Table of Content

01 February 2010, Volume 31 Issue 3
Effect of Calcium-induced Whey Protein Encapsulation System on Stability of Vitamin B12
CHAI Zhi,LENG Xiao-jing*
2010, 31(3):  1-4.  doi:10.7506/spkx1002-6300-201003001
Asbtract ( 1451 )   HTML ( 3)   PDF (306KB) ( 418 )  
Related Articles | Metrics

Whey protein was used as the carrier to encapsulate and protect vitamin B12. Results indicated that network microstructure formed by heat-denatured whey protein isolate (WPI) under the induction of Ca2+ could effectively encapsulate vitamin B12. The optimal concentrations of WPI and calcium for encapsulation efficiency of vitamin B12 were 8% and 0.2 mol/L, respectively. The highest encapsulation efficiency was up to 50% under this optimal condition. Moreover, under mimic gastric conditions, this encapsulation system exhibited a delayed release of vitamin B12 to reduce the damage of vitamin B12 by acid or pepsin. On the other hand, under mimic intestinal environments, vitamin B12 could be completely released from protein encapsulation system within 2 h.

Inhibition Effect of Antioxidants on Whey Protein Oxidation Caused by Hydroxyl Radical Generation System
KONG Bao-hua1,SUN Yan1,XIONG You-ling2
2010, 31(3):  5-10.  doi:10.7506/spkx1002-6300-201003002
Asbtract ( 1581 )   HTML ( 2)   PDF (506KB) ( 582 )  
Related Articles | Metrics

The inhibition effect of antioxidants on whey protein isolate (WPI) oxidation caused by reactive oxygen species was investigated. Experiments were divided into three groups designated as control group without antioxidants, α-tocopherol group with and BHA group. Protein oxidation was evaluated by the change of carbonyl group, total sulfydryl group, bityrosine, hydrophobicity and SDS-PAGE after oxidation for 1, 5 or 12 h. Results indicated that protein oxidation significantly increased the content of carbonyl group, dityrosine and hydrophobicity of WPI (P < 0.05). However, compared with control group, WPI with α-tocopherol or BHA after 5 h oxidation exhibited 35.11% and 50.15% decrease in carbonyl group and 27.73% and 38.82% increase in sulfydryl group, respectively. Therefore, the addition of antioxidants can result in the decrease in polymerization of proteins to inhibit the oxidation of WPI.

Effects of Washing Media and Thermal Treatment on Gel Properties of Painted Lizardfish (Trachinocephalus myops) Surimi
CHEN Hai-hua1,2,XUE Chang-hu2
2010, 31(3):  11-18.  doi:10.7506/spkx1002-6300-201003003
Asbtract ( 1559 )   HTML ( 0)   PDF (640KB) ( 457 )  
Related Articles | Metrics

Lizardfish are considered as a low-market-value fish in Southeast Asia due to their appearance and susceptibility to spoilage. Most studies focused on the gel-forming ability of Saurida, while no information regarding gel-forming ability of painted lizardfish (Trachinocephalus myops) has been available. The present study aimed to investigate the effects of washing media and thermal treatment on gel properties of painted lizardfish surimi. Results showed that no modori phenomenon of lizardfish surimi occurred during preheating at a temperature from 30 to 100 ℃. Washing with CaCl2 solution could remarkably improve the gelforming properties of lizardfish surimi. Maximum values of break force and deformation were obtained using sequential treatment of washing with 0.5% CaCl2 followed by directly heating at 100 ℃ for 20 min, which resulted in the formation of an ordered and compact structure with finer strands and smaller pores in the matrix revealed by scanning electronic microscopy (SEM) observation.

Evaluation of in vitro Antioxidant Activities of Extracts from Pyrola corbieri
MO Zheng-chang1,2,DENG Jing1,2,JI Guang-quan1,2,YANG Juan2,*
2010, 31(3):  19-21.  doi:10.7506/spkx1002-6300-201003004
Asbtract ( 1367 )   HTML ( 2)   PDF (300KB) ( 367 )  
Related Articles | Metrics

Antioxidant activities in vitro of extracts from Pyrola corbieri using petroleum ether, chloroform, ethyl acetate, n-butanol or water were evaluated by salicylic acid, 2,2-diphenyl-1-picrylhydrazyl (DPPH·) and ferric reducing/antioxidant power (FRAP) assays under the reference of vitamin C. Results indicated that antioxidant activities of extracts exhibited an obvious difference due to different evaluation methods. Similarly, the antioxidant activities of extracts with different polarities measured by the identical assay method also exhibited a significant difference.

Colony Structure and Nutritional Composition Analysis of Cultivated Nostoc commune Vauch.
YAN Chun-lan1,2,DENG Zhong-yang1,HU Zheng-yu1,*
2010, 31(3):  22-25.  doi:10.7506/spkx1002-6300-201003005
Asbtract ( 1588 )   HTML ( 0)   PDF (443KB) ( 946 )  
Related Articles | Metrics

Cultivated Nostoc commune Vauch. was used as the raw material to determine its biochemical composition and structure. Results indicated that surface trichomes of cultivated N. commune exhibited more tight arrangement than that of the interiors. Meanwhile, some trichomes in the interior were enveloped by sheath. Cultivated N. commune contained 17.46% protein that was composed of 16 kinds of amino acids and 0.53% fatty acid. Compared to wild N. commune, lower fatty acid and vitamin contents were determined in cultivated N. commune, which, however, was rich in mineral elements and exhibited contents of heavy metals such as As, Pb, Hg and Cd that were much lower than the maximum threshold stipulated in the Chinese national food hygiene standards.

Characteristics of Intramuscular Connective Tissues during Growth of Wuzhumuqin Sheep
HOU Xiao-wei,LI Jin-zhuang,BORJIGIN Gerelt*
2010, 31(3):  26-29.  doi:10.7506/spkx1002-6300-201003006
Asbtract ( 1385 )   HTML ( 0)   PDF (189KB) ( 338 )  
Related Articles | Metrics

Wuzhumuqin sheep aged from 1 to 18 months were used as the subjects to study the change in total amount of collagen, thermal solubility of collagen and thermal denaturation temperature in intramuscular connective tissues by hydroxyproline and DSC methods during the growth process. Results showed a significant decrease in total amount of collagen and thermal solubility of collagen in connective tissues, endomysium and perimysium during the growth of sheep (P < 0.05). Moreover, the collagen amount and thermal solubility of collagen in endomysium were significantly higher than that in perimysium. Thermal denaturation temperature in connective tissues and endomysium exhibited a gradual increase during the growth of sheep. However,thermal denaturation temperature in perimysium exhibited a reverse change. These investigations reveal significant impacts in livestock industry and product processing.

Isolation and Characterization of Polysaccharides from Momordica charantia L. Fruits
LIU Guo-ling1,NING Zheng-xiang2,GUO Hong-hui1
2010, 31(3):  30-34.  doi:10.7506/spkx1002-6300-201003007
Asbtract ( 1424 )   HTML ( 1)   PDF (346KB) ( 407 )  
Related Articles | Metrics

Crude polysaccharides (MCP) were extracted from dried fruits of Momordica charantia L. through sequential steps of hot water extraction, ethanol precipitation and Sevag protein removal and purified/fractionated by DEAE-cellulose-52 exchange chromatography to obtain four fractions (MCP-A, MCP-B, MCP-C and MCP-D). MCP-A1 with high purity was obtained through further purification of MCP-A by Superdex G-100 gel filtration chromatography and its purity was identified by high performance gel permeation chromatography (HPGPC). Results indicated MCP-A1 was a homogeneous polysaccharide with average molecular weight of 93577 D. Qualitative chemical reaction showed that MCP-A1 was a neutral polysaccharide that contained uronic acid, rather than proteins, nucleic acids and starch. Typical absorption peaks of this polysaccharide were also observed in infrared (IR) spectrum.

Granular Property and Digestibility of Yinmi Starch
ZHAO Na1,WANG Lan2,SHEN Jie1,SUN Zhi-da1,*,XIE Bi-jun1
2010, 31(3):  35-38.  doi:10.7506/spkx1002-6300-201003008
Asbtract ( 1354 )   HTML ( 1)   PDF (495KB) ( 792 )  
Related Articles | Metrics

The morphological and physicochemical properties of Yinmi (a Chinese traditional food made from selected glutinous rice through sequential steps of soaking, cooking and shade drying) starch including granular structure, color and crystal structure were studied using scanning electronic microscope, colorimeter and X-ray diffraction techniques. Results showed that Yinmi starch was gel-like granules or diffused crystals. Digestion rate of Yinmi starch was increased due to the enhanced amount of rapid digestible starch (RDS) and declined amount of resistant starch (RS). The glycemic index (GI) was estimated using the equation of GI = 39.71 + 0.549HI built by Goni’s research group. A negative correlation between glycemic index or hydrolysis index and resistant starch content was observed.

Effect of High-voltage Pulsed Electric Field on Proanthocyanidins Content in Freshly Brewed Dry Red Wine
SU Hui-na,HUANG Wei-dong,ZHAN Ji-cheng,WANG Xiu-qin*
2010, 31(3):  39-43.  doi:10.7506/spkx1002-6300-201003009
Asbtract ( 1452 )   HTML ( 0)   PDF (554KB) ( 359 )  
Related Articles | Metrics

In order to shorten the aging time of red wine and improve its quality, high-voltage pulsed electric field was used to treat red wine. Compared with spontaneous aging, the evolution of proanthocyanidins was monitored by reversed-phase high performance liquid chromatography (RP-HPLC) coupled with UV-visible detector to evaluate the effect of high-voltage pulsed electric field on proanthocyanidins content in freshly brewed dry red wine. After the treatment of high-voltage pulsed electric field, the content, average polymerization degree and monomer composition of proanthocyanidins exhibited a significant change, which revealed the similar effect with the spontaneous aging of red wine in a bottle. During the treatment of electric field below 18 kV/cm, the aging effect of treated wine was more close to the spontaneous evolution of wine with increasing electric field intensity. However, the aging effect on red wine exhibited a decrease trend when the electric filed intensity was over 24 kV/cm. These investigations suggest that appropriate pulsed electric field treatment could accelerate the mature and aging of red wine and improve its quality.

Improved Textural Properties of Sausages Made from PSE Pork with Transgluminase
SHANG Yong-biao1,2
2010, 31(3 ):  44-48.  doi:10.7506/spkx1002-6300-201003010
Asbtract ( 1110 )   HTML ( 0)   PDF (286KB) ( 276 )  
Related Articles | Metrics

In order to explore the effects of transgluminase (TG) and treatment processing on textural properties of sausages made from PSE pork, the cooking loss, breaking strength and color parameters of PSE and RFN pork were determined under the conditions of various TG concentrations, TG treatment time, and heating methods. Results showed that gel strength of sausages exhibited a significant enhancement at the condition of 0.3% TG added in pork, but the cooking loss also exhibited an obvious increase at this condition. The optimal TG treatment time at 4 ℃ was 2 h. In addition, compared to direct heating in 75 ℃ water bath, heating in water batch with a gradual increase in temperature from 25 ℃ to 75 ℃ resulted in higher gel strength and lower cooking loss for pork. Although TG concentration and treatment time exhibited less effect on color parameters, L* and a* of gel could exhibited a significant effect due to heating methods. In conclusion, TG treatment can promote protein cross-linking in pork and improve the quality of sausages made from PSE pork.

Pasting and Rheological Properties of Rice Starch and Starch Phosphate with Different Degrees of Substitution
LIN Qin-lu1,XIAO Hua-xi1,LI Li-hui1,LIU Yi-yang2,TIAN Wei2
2010, 31(3):  49-54.  doi:10.7506/spkx1002-6300-201003011
Asbtract ( 1468 )   HTML ( 0)   PDF (375KB) ( 509 )  
Related Articles | Metrics

Rice starch phosphate with substitution degrees of 0.028, 0.049, 0.073 and 0.14 were obtained through esterification reaction between rice starch and sodium dihydrogen phosphate at different temperatures. The pasting and rheological properties of rice starch and starch phosphate with different degrees of substitution (DS) were determined using rapid viscosity analyzer (RVA) and rheometer. Results showed that the incorporation of phosphate in rice starch resulted in reduced pasting temperature and increased of viscosity. Compared to rice starch, rice starch phosphate exhibited better anti-retrogration property. In addition, starch phosphate with high DS had high capacity to resist shearing force and declined pasting hardness and enhanced pasting viscosity.

Effect of Processing Technology on Properties of Surimi-Konjac Compound Gel
YANG Li-li1,2,XIONG Shan-bai1,2,*,SUN Jian-qing1,2
2010, 31(3):  55-59.  doi:10.7506/spkx1002-6300-201003012
Asbtract ( 1334 )   HTML ( 3)   PDF (634KB) ( 624 )  
Related Articles | Metrics

In order to optimize the preparation processing of surimi-konjac compound gel, konjac powder and silver carp surimi were used as the materials to investigate the effects of processing technologies including addition order of NaCl, konjac gel types, heating and cooling methods on texture properties, whiteness, water-holding capacity (WHC) and sensory quality of surimireversible konjac gel. In addition, the microstructure of this compound gel was examined using scanning electron microscope and HE staining. Results indicated that NaCl addition order had a significant effect on textural properties of the compound gel. The best quality of the compound gel was achieved through mixing 50% surimi and 50% reversible konjac gel followed by adding 1.5% NaCl, which revealed compact microstructure, high hardness and WHC. Meanwhile, no obvious difference in textural properties and sensory quality of the compound gel was observed between one-step heating and two-step heating. However, one-step heating provided higher whiteness, WHC and more compacted microstructure for the compound gel. Moreover, reversible konjac gel offered higher texture properties, whiteness, WHC and sensory quality of the compound gel than konjac sol or irreversible konjac gel.

Propolis Essential Oil Extracted by Different Methods: Chemical Composition Analysis and Antibacterial Activity Evaluation
XU Xiang1,2,DONG Jie1,2,DING Xiao-yu1,YANG Jia-lin1,SUN Li-ping1,2,*
2010, 31(3):  60-63.  doi:10.7506/spkx1002-6300-201003013
Asbtract ( 1708 )   HTML ( 0)   PDF (216KB) ( 478 )  
Related Articles | Metrics

In this work, propolis essential oil was obtained by steam distillation extraction and supercritical CO2 extraction, respectively. Added together, 50 components in resulting propolis essential oils were identified by GC-MS method. Propolis essential oils extracted by both methods exhibited strong inhibition effects against Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa in vitro. Stronger inhibition effect of propolis essential oil extracted by supercritical CO2 extraction on the three species of bacteria than that of propolis essential oil extracted by steam distillation extraction was observed.

Effect of Freezing Rate on Characteristics of Wenshi Chicken
LIAO Cai-hu,RUI Han-ming*
2010, 31(3):  64-68.  doi:10.7506/spkx1002-6300-201003014
Asbtract ( 1378 )   HTML ( 0)   PDF (340KB) ( 518 )  
Related Articles | Metrics

In order to investigate the characteristics of Wenshi chicken during freezing process, four freezing rates such as ultrarapid freezing at 11.46 cm/h, rapid freezing at 4.21 or 2.07 cm/h and slow freezing at 0.25 cm/h were studied to examine the effect on characteristics of chicken through evaluating its drip loss rate, protein denaturation and texture. Results indicated that the reduction rate of salt-soluble protein content and Ca2+-ATPase activity and drop loss rate in Wenshi chicken displayed a change trend to first drop and then rise as freezing rate rose. However, No obvious change in the activity of other ATPase enzymes was observed at different freezing rate conditions. Differential scanning calorimetric (DSC) analysis exhibited that protein denaturation after being frozen had a good correlation with traditional methods (R2 = 0.8367). Denaturation degree of myosin heads was larger than sarcoplasmic protein and myosin tails throughout freezing process. With increasing freezing rate, the hardness and chewiness of Wenshi chicken exhibited an increase, while the elasticity and resilience exhibited a decrease. According to comprehensive evaluation and texture analysis, increasing freezing rate will be helpful to maintain original quality of Wenshi chicken, but ultra rapid freezing rate can result in the damage of its original quality.

Quality Characteristic Analysis of Three Apple Varieties during Growth and Development Periods
DUAN Liang-liang1,GUO Yu-rong1,*,LI Jin-yun1,KONG Xiang-hong2,QIU Nong-xue1,DENG Hong1
2010, 31(3):  69-73.  doi:10.7506/spkx1002-6300-201003015
Asbtract ( 1698 )   HTML ( 0)   PDF (277KB) ( 544 )  
Related Articles | Metrics

Three apple varieties including Qinguan, Fuji and Granny Smith were selected to investigate the quality characteristics during growth and development periods. The contents of total soluble solids and vitamin C were determined according to relevant Chinese national standards. The content of total acids was determined according to Trade Standards. The fruit firmness was determined using texture analyzer. The aromatic components in ripe fruits were analyzed by head-space solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrophotometer (GC-MS). Results showed a significant difference in the above indicators among the apple varieties during growth period. The content of total acids, ascorbic acid, and fruit firmness of the apple varieties exhibited a decrease trend, while the content of total soluble solids and soluble solid-acid ratio exhibited an increase trend. Qinguan and Fuji contained higher soluble solids than Granny Smith and Qinguan exhibited little change in fruit firmness during fruit development. Granny Smith contained higher total acids and vitamin C than Qinguan and Fuji. Added together, a total of 43 aromatic compounds were identified from three ripe apple varieties. There were significant differences in aromatic components among the apple varieties. Major aromatic components in Qinguan and Fuji were esters and alcohols, which belonged to fruit flavor type; however, major aromatic components in Granny Smith were aldehydes and alcohols, which belonged to green flavor type. Ethyl caproate, hexyl acetate and 2-methyl-1-n-butyl in Fuji and Qinguan had smaller difference. Compared to Granny Smith, 2-methyl-1-n-butyl in Fuji and Qinguan exhibited a significant difference. The content of (E)-2-hexenal in Granny Smith was 37.042%, which was much higher than that in Qinguan.

Effect of Sucrose on Thermal Stability and Degradation Kinetics of Peony Anthocyanins
FAN Jin-ling1,ZHU Wen-xue1,*,GONG Wei-dong2,SHEN Jun-wei1,HAN Jiang-nan1,MA Hai-le1,GUO Bing-yin1
2010, 31(3):  74-78.  doi:10.7506/spkx1002-6300-201003016
Asbtract ( 1690 )   HTML ( 0)   PDF (408KB) ( 601 )  
Related Articles | Metrics

In this work, thermal stability and degradation kinetics of peony anthocyanins were investigated under various sucrose concentrations (11, 30, 45 or 62°Brix) during heating. Results indicated that thermal degradation kinetic model of peony anthocyanins was a first-order degradation kinetic process. The half-life of anthocyanin degradation was shortened due to increased temperature. During the degradation process of anthocyanin monomers in solution, the degradation rate exhibited a drop order of cyanidin-3-O-glucoside > peonidin-3-O-glucoside >cyanidin-3,5-di-O-glucoside > peonidin-3,5-di-O-glucoside. Degradation of anthocyanins exhibited a decrease trend with increasing sucrose concentration during heating. However, the thermal degradation of anthocyanins did not obey the first-order kinetic model. In addition, the browning index was increased with increasing temperature and heating time. However, the degradation of anthocyanins with sucrose revealed the lower browning index than the sample without sucrose. These results suggest that the presence of sucrose reduces anthocyanin degradation in time-, temperature- and concentration-dependent manners.

Hydrolyzed Rape Bee Pollen Ethanol Extract: Qualitative and Quantitative Analysis of Flavonol and Antioxidant Activity Evaluation
YANG Jia-lin1,SUN Li-ping1,*,XU Xiang1,ZHU Qing2
2010, 31(3 ):  79-82.  doi:10.7506/spkx1002-6300-201003017
Asbtract ( 1253 )   HTML ( 0)   PDF (393KB) ( 618 )  
Related Articles | Metrics

Ethanol (80% concentration) extract of rape pollen was hydrolyzed with hydrochloric acid and the resulting hydrolysate was analyzed for the qualification and quantitation of flavonol by thin layer chromatography (TLC), UV-Vis spectroscopy and HPLC, and was subjected to antioxidant activity evaluation. TLC results showed that bands with 0.59 and 0.71 of Rf value were quercetin and kaempferol, respectively. The contents of quercetin and kaempferol in the hydrolysate were 0.40 mg/g and 3.98 mg/g, respectively. The scavenging capacity of rape pollen ethanol extract against DPPH free radicals was poorer than that of its hydrolysate. Preparative high performance liquid chromatography was used to separate a flavonol, which was identified as kaempferol 3-O-(2"-O-β-D-glucopyranosyl)-β-D-glucopyranoside by MS and NMR. In this work, TLCDPPH was used to track the antioxidant activity of flavonol in rape pollen, which will provide useful references for further studying the antioxidant activity of active compounds in rape pollen.

Effect of Cooking Temperature during Preparation on Properties of Instant Rice
ZHENG Zhi,ZHANG Yuan-ji*,ZHOU Hui-xi,LUO Shui-zhong,JIANG Shao-tong
2010, 31(3):  83-86.  doi:10.7506/spkx1002-6300-201003018
Asbtract ( 1506 )   HTML ( 1)   PDF (378KB) ( 441 )  
Related Articles | Metrics

The effect of cooking temperature during preparation on properties of hot-air dried instant rice were investigated. Results indicated that cooking temperatures of 100, 106 ℃ and 110 ℃ had no significant effect on rehydration rate and ratio of hot-air dried instant rice, but had a significant effect on hardness and viscosity. Instant rice prepared at cooking temperature of 100 ℃ exhibited higher rehydration rate and ratio than at cooking temperature of 106 ℃ or 110 ℃ An increase from 215.199 g to 279.332 g in hardness and an increase from 30.966 g to 43.608 g in stickiness were exhibited in instant rice after rehydration due to increased cooking temperature during preparation. The porous and harsh surface of instant rice prepared at cooking temperature of 100 ℃ was observed under scanning electronic microscope (SEM), in contrast, less porous and smooth surface of instant rice prepared at cooking temperature of 106 ℃ or 110 ℃ was observed. These studies suggest that the appropriate cooking temperature for the preparation of hot-air dried instant rice is 100 ℃.

Adsorption Kinetics of Modified Pomelo Peel Cellulose towards Lead Ions
LUO Jun,GE Jing-wei,YANG Xiao-bo,LI Xiao-ding*
2010, 31(3):  87-90.  doi:10.7506/spkx1002-6300-201003019
Asbtract ( 1538 )   HTML ( 0)   PDF (300KB) ( 485 )  
Related Articles | Metrics

Succinic anhydride modified pomelo peel cellulose as biosorbents, Cell 5 and Cell 6 were used to remove lead ions from aqueous solutions. Adsorption equilibrium and kinetics of lead ions from aqueous solutions onto modified pomelo peel cellulose were investigated. Adsorption kinetics of lead ions onto Cell 5 and Cell 6 obeyed pseudo-second-order equation. Adsorption equilibrium studies demonstrated that the bio-adsorption complied with Langmuir isotherm model. The maximum adsorption capacities of Cell 5 and Cell 6 were 142.86 mg/g and 181.82 mg/g, respectively. These investigations suggest that modified pomelo peel cellulose is an attractive candidate for removing lead ions from aqueous solutions.

Effect of Freeze Condensation on Quality of Litchi Juice
ZENG Yang,ZENG Xin-an*
2010, 31(3):  91-93.  doi:10.7506/spkx1002-6300-201003020
Asbtract ( 1416 )   HTML ( 0)   PDF (226KB) ( 485 )  
Related Articles | Metrics

In order to investigate the effect of freeze condensation on quality of litchi juice, the concentrated litchi juice obtained through multiple-step freeze condensation with various soluble solid content was used to analyze nutrient content, pH, total acids, reducing sugar, protein as well as vitamin C after the recovery. Results showed that soluble solid content in the concentrated juice reached up to 45.3°Brix through a three-step condensation; while, no obvious change of nutrient content in recovered juice was observed. Although vitamin C exhibited a decreasing trend, retention rate of vitamin C in recovered juice was up to 85%. These investigations suggest that freeze condensation is an effective strategy to concentrate litchi juice with intact original quality.

Optimal Roller Speed of Drum-type Dehydrated Vegetable Drier
MA Rong-chao,QIN Wen,WU Wei-xiong
2010, 31(3):  94-96.  doi:10.7506/spkx1002-6300-201003021
Asbtract ( 1585 )   HTML ( 0)   PDF (218KB) ( 487 )  
Related Articles | Metrics

Vegetables can reduce water content after dehydration, which is benefit for long-term preservation, transportation as well as carryover at normal temperature after dehydration. Drum-type drier has been widely employed in some small processing plants to produce dehydrated vegetables. However, the roller speed is one of the key factors that affect the quality of dehydrated vegetables. In this study, stress condition and movement track of vegetables in drum were analyzed to acquire the optimal roller speed and corresponding parameters, which will provide theoretical basis to improve the quality of dehydrated vegetables.

Comparison of Nutritional Components in Surface Mucus and Muscle of Catfish Grown in Dongting Lake Area
HAN Qing1,LI Li-li2,HUANG Chun-hong1,ZHU Zhi-hong1,WANG Bo1
2010, 31(3):  97-101.  doi:10.7506/spkx1002-6300-201003022
Asbtract ( 1662 )   HTML ( 1)   PDF (220KB) ( 810 )  
Related Articles | Metrics

This study deals with comparisons of nutritional components in surface mucus and muscle of catfish (Silnrus asotus) from Dongting Lake area. Results showed that water content, crude protein, crude fat and crude ash were (95.34 ± 2.38) %, (2.54 ± 0.22) %, (0.52 ± 0.08) % and (1.55 ± 0.17) % in surface mucus; (77.68 ± 3.14) %, (13.81± 0.43) %, (3.79 ± 0.11) % and (4.54 ± 0.15) % in muscle of catfish, respectively. The water content in surface mucus of catfish was significantly higher than that of muscle (P<0.01), while crude protein, crude fat and crude ash in muscle were significantly higher than those of surface mucus (P<0.01). In dry samples, minerals such as Ca, Zn, Fe and Cu in surface mucus were much higher than those in muscle. The ratios of Zn and Cu, Zn and Fe were rational. Surface mucus of catfish contained 18 kinds of amino acids; so did muscle. The contents of total amino acids (WTAA), total essential amino acids (WEAA), total half-essential amino acids (WHEAA), total nonessential amino acids (WNEAA) in dry samples were (80.46 ± 0.89) %, (25.62 ± 0.69) %, (4.94 ± 0.19) % and (49.91 ± 0.38) % in surface mucus; (81.65 ± 0.80) %, (32.74 ± 0.29) %, (7.35 ± 0.07) % and (41.57 ± 0.55) % in muscle of catfish, respectively. The content of WEAA, WHEAA and WNEAA was significantly difference between surface mucus and muscle (P <0.05). The essential amino acids index (EAAI) was 59.43 and 64.53, respectively. According to nutrition evaluation, amino acid score (AAS) and chemical score (CS), limited amino acids in surface mucus and muscle were Trp, Met and Cys. There were 6 saturated fatty acids (SFA), 5 mono-unsaturated fatty acids (MUFA) and 5 poly-unsaturated fatty acids (PUFA) in surface mucus of catfish, while 6 SFA, 2 MUFA and 4 PUFA in muscle of catfish were observed. The SFA, MUFA and PUFA in fatty aids were (30.98 ± 1.91) %, (28.76 ± 0.68) % and (30.93 ± 0.73) % in surface mucus; (35.03 ±1.31) %, (21.64 ± 0.83) % and (21.41 ± 0.85) %, respectively. The amount of EPA + DHA in fatty acids was (22.27 ± 0.28) % and (7.40 ± 0.22) %, respectively. The amount of MUFA, EPA, DHA, OUFA and EPA + DHA in surface mucus of catfish was significantly higher than muscle (P<0.01). The amount of SFA in surface mucus was significantly lower than muscle (P<0.05). The ARA in fatty aids of surface mucus was (3.21 ± 0.38) %, but not detected in muscle.

Properties of Carboxymethylation Product from Mechanically Activated Cassava Starch (Ⅰ)
TAN Yi-qiu1,ZHAO Han-min1,NONG Ke-liang1,HUANG Zu-qiang2
2010, 31(3):  102-105.  doi:10.7506/spkx1002-6300-201003023
Asbtract ( 1167 )   HTML ( 0)   PDF (253KB) ( 361 )  
Related Articles | Metrics

Carboxymethyl starch was prepared by dry method from cassava starch that was mechanically activated for 60 min using a stirring-type ball mill as the starting material, NaOH as the catalyst and ClCH2COOH as the etherification agent. The solubility, transparency, frozen-thaw stability, anti-aging capability, anti-biodegradation capability and apparent viscosity of prepared carboxymethyl starch were investigated. Results indicated that carboxymethyl starch products from activated cassava starch exhibited high solubility, better transparency, strong anti-biodegradation capability, high apparent viscosity, excellent frozen-thaw stability and anti-aging capability.

Structure and Properties of Konjac Glucomannan Membrane in Alcohol Solution
CHEN Shi-yong1,LU Wen-ping1,WANG Chao1,2,*,CHEN Wen-ping1,JIANG Gui-lin1, JIANG Fa-tang1,2,ZHONG Xiao-ling1
2010, 31(3):  106-109.  doi:10.7506/spkx1002-6300-201003024
Asbtract ( 1575 )   HTML ( 0)   PDF (641KB) ( 1018 )  
Related Articles | Metrics

Konjac glucomannan membrane (KGM) was prepared in alcohol solution through sequential treatments of swelling followed by casting. The aggregation structure and properties of KGM membrane were investigated in this study. Results indicated that alcohol could promote the formation of partially ordered and stacked membrane structure of konjac glucomannan, increase microcrystalline rate of KGM and improve thermal stability of KGM. In addition, with increasing alcohol concentration, an increase in the break strength of thin membrane was observed, along with a decrease in elongation, transmission, water activity and water-absorption rate of KGM membrane.

Chaya (Cnidoscolus spp.) Leaves: Antinutritional Factor Analysis and Effect of Treatment Processing on Cyanogenic Glycosides Content
FAN Dong-cui,ZHOU Cai-qiong*
2010, 31(3):  110-113.  doi:10.7506/spkx1002-6300-201003025
Asbtract ( 1558 )   HTML ( 0)   PDF (259KB) ( 307 )  
Related Articles | Metrics

In order to study anti-nutritional factors in introduced chaya leaves, major anti-nutritional compositions were analyzed and cyanogenic glycosides in chaya leaves were also determined to evaluate their change due to different treatment processing methods. Results indicated that chaya leaves contained cyanogenic glycosides, alkaloids, steroidal saponins and tannins. Cyanogenic glycosides were major anti-nutritional factors. The content of cyanogenic glycosides exhibited a gradual decrease in chaya through treatments such as steam heating, hot-air drying, microwave treatment and boiling water treatment. The residual cyanogenic glycosides were 31.31%, 40.69%, 3.74% and 2.17% in chaya leaves treated by the above methods, respectively. According to experimental investigations, the content of cyanogenic glycosides was lower than 5 mg/kg after treatment with microwave or boiling water, which meets the edible requirements.

Effect of C/N Ratio on Astaxanthin Synthesis in Yeast Phaffia rhodozyma CS0217
MEI Yan-zhen,WANG Li-mei,ZHENG Li-xue,QI Bin*
2010, 31(3):  114-117.  doi:10.7506/spkx1002-6300-201003026
Asbtract ( 1191 )   HTML ( 0)   PDF (305KB) ( 372 )  
Related Articles | Metrics

Astaxanthin synthesis in yeast Phaffia rhodozyma CS0217 was greatly dependent on C/N ratio. The amount of synthesized astaxanthin exhibited a dramatic decrease due to the decrease of C/N ratio. The highest astaxanthin productivity was 2.48 mg/g at the C/N ratio of 4.5:0.1. High C/N ratio could result in a low budding rate of yeast, which was benefit for astaxanthin synthesis. The optimal budding rate of yeast should be controlled below 0.5. Furthermore, the addition of cycloheximide in the culture medium for yeast could inhibit the activity of critical enzymes that involved in the conversion from β -carotene to astaxanthin.

Granular Properties of Water Caltrop Starch from Three Varieties
YANG Feng1,GU Nan1,ZHAO Guo-hua1,2,*
2010, 31(3):  118-122.  doi:10.7506/spkx1002-6300-201003027
Asbtract ( 1583 )   HTML ( 0)   PDF (585KB) ( 366 )  
Related Articles | Metrics

The granular properties of water caltrop starch from three varieties (Trapa acornis Nakano from Nanhu, Trapa quadrispinosa Roxb from Nanhu and Trapa biocornis Osbeck from Xichang) were investigated using scanning electron microscope, laser light scattering analyzer, X-ray diffraction and differential scanning calorimeter. Results indicated that most starch granules of water caltrop from three varieties were oval-shaped and some starch granules were round-shaped. The starch granules exhibited smooth surface with obvious birefringence phenomena and “X” polarized mode with the umbilical point close to the center of starch granules. The granular size of more than 85% of water caltrop starch from three varieties was ranged 7.96- 63.37 μm. Average volume of water caltrop starch granules from Trapa acornis Nakano, Trapa quadrispinosa Roxb and Trapa biocornis Osbeck were 21.24, 19.67 μ m and 38.52 μ m, respectively. Starch from Trapa acornis Nakano and Trapa quadrispinosa Roxb displayed an A-type X-ray diffraction pattern with relative crystallinity of 39% and 28%, respectively. While starch from Trapa biocornis Osbeck displayed a Ca-type diffraction pattern with relative crystallinity of 40%. The initial, peak and termination temperatures for the gelatinization of water caltrop starch from three varieties were 75.2-78.1, 76.6-81.8 ℃ and 80.7 - 86.0 ℃, respectively. The enthalpy for the gelatinzation of three kinds of starch was 15.3 - 19.7 J/g.

Effects of Ripening Temperature and Time on the Quality Characteristics of Semi-hard Cheese
HE Jia-liang1,LI Kai-xiong2,*,CHEN Shu-xing1,KANG Huai-bin1
2010, 31(3):  123-126.  doi:10.7506/spkx1002-6300-201003028
Asbtract ( 1223 )   HTML ( 0)   PDF (300KB) ( 371 )  
Related Articles | Metrics

The changes in quality characteristics of cheese stored at 4, 10 ℃ or 16 ℃ during 90 days of ripening period was determined. Results revealed that pH exhibited a change trend to first decrease and then gradually increase until a stable platform during ripening period of 90 days. Soluble nitrogen content of semi-hard cheese at pH 4.6 or in 12% trichloroacetic acid exhibited a gradual increase. The total number of lactic acid bacteria exhibited a gradual decrease. A significant effect of ripening temperature on cheese sensory quality, pH, protein degradation and total number of lactic acid bacteria was observed. The best sensory quality of cheese was achieved at 4 ℃ for 90 days of ripening period or at 10 ℃ for 45 days of ripening period. However, weak sensory quality of cheese was observed at 16 ℃ of ripening temperature. Therefore, according to the variation rule of sensory quality and other parameters, the optimal ripening temperature and time for semi-hard cheese are 10 ℃ and 45 days, respectively.

in vitro Antioxidant and Antibacterial Activities of Pepsin Hydrolysate of Half-fin Anchovy (Setipinna taty)
SONG Ru1,2,WANG Dong-feng2,XIE Chao1,WANG Xian1
2010, 31(3 ):  127-131.  doi:10.7506/spkx1002-6300-201003029
Asbtract ( 1148 )   HTML ( 0)   PDF (245KB) ( 513 )  
Related Articles | Metrics

Half-fin anchovy (Setipinna taty) homogenate was hydrolysated by pepsin. Protein yield, contents of soluble peptides and degree of hydrolysis were analyzed and in vitro antioxidant and antibacterial activities of the hydrolysates were also evaluated. Results showed protein extract rate, soluble peptides contents, degree of hydrolysis of half-fin anchovy pepsin hydrolysate were (110 ± 4.81)%, (81.78 ± 0.04)% and (18.12 ± 0.39)%, respectively. The relative contents of essential amino acids in half-fin anchovy hydrolysate (HAH) reached 37.91%. HAH showed strong radical scavenging activity against hydroxyl and DPPH radicals with the ED50 values of 4.55μg/mL and 4.46 μg/mL, respectively. The reducing power increased with rising concentration and the metal chelating ability was equivalent to that of EDTA at the 3.4μg/mL or 13.6 μg/mL. HAH displayed broad antibacterial spectra in vitro and the antibacterial effecacy against Escherichia coli was equal to 13.21-15.44 mcg/mL of ampicillin of and 325.00 - 340.00 U/mL of streptomycin sulfate (P> 0.05).

Purification and Anti-bacterial Activity Evaluation of Anti-bacterial Peptides from Skin of Rana chensinensis
WANG Zhan-yong1,LI Ning1,SU Ting-ting2
2010, 31(3):  132-135.  doi:10.7506/spkx1002-6300-201003030
Asbtract ( 1235 )   HTML ( 2)   PDF (235KB) ( 822 )  
Related Articles | Metrics

Rana chensinensis skin was extracted using acidified methanol for preparing anti-bacterial peptides and the resulting crude extract was then purified by gel filtration chromatography. Purified anti-bacterial peptides were found to be rich in F2 fraction up to 90% by tandem Sephadex G-50 and G-25 column chromatography. The purified anti-bacterial peptides could effectively inhibit the growth of Gram-positive bacteria, Gram-negative bacteria and fungus. The minimum inhibitory concentrations (MIC) were 0.2 mg/mL against Staphylococcus aureus and Streptococcus, 0.4 mg/mL against Bacillus subtilis and Escherichia coli, 0.8 mg/mL against Bacillus cereus, 1.2 mg/mL against Candida albicans, 1.5 mg/mL against Saccharomyces cerevisia and Mucor, and 2.0 mg/mL against Rhizopu.

Basic Research
Processing and Quality Evaluation of Dumplings
LAN Jing1,FU Bin-xiao2,Esey Assefaw2,WANG Le-kai1, ZHAO Lin1,DAI Chang-jun1,LI Hui1,LI Wan1,ZHAO Nai-xin1
2010, 31(3):  136-141.  doi:10.7506/spkx1002-6300-201003031
Asbtract ( 2472 )   HTML ( 23)   PDF (254KB) ( 770 )  
Related Articles | Metrics

In order to establish a protocol for dumpling processing and quality evaluation method in laboratory, fifteen flour samples from wheat areas in China, Canada, Australia and USA were selected as the subjects in this study. The effects of mixing speed and time, water-absorbing capacity of dough, resting time and sheeting gaps on quality of dumpling were examined. Results indicated that mixing at the speed of 68 r/min in a GRL-1000 mixer for 12 min, 40%-47% water-absorbing amount for flour, two-step dough mixing method including first step mixing for 10 min followed by 5 min of resting and second step mixing for 2 min followed by 5 min of resting, seven-step dough sheeting including the gap settings of 5.0, 4.0, 3.0, 2.0, 1.5, 1.2mm and 1.0 mm generated the dough with optimal quality for dumpling processing. Raw and cooked dumpling wraps were evaluated from appearance and texture through a sensory panel and instruments. A positive correlation between the color of raw dumpling skin L*1h and the color evaluated by sensory panel was observed (r = 0.79, P < 0.01); Similarly, a positive correlation between the elasticity index of cooked dumpling determined by instruments and the elasticity index evaluated by sensory panel was also achieved (r = 0.88, P < 0.01). However, a difference in appearance and texture of dumplings was exhibited due to different resources of flour. Although Chinese wheat flour provided good elasticity during dumpling preparation, acceptable firmness of dumplings during cooking was not exhibited. Australian and American flour offered good color and elasticity for dumplings, but processed dumplings exhibited soft texture. Canadian wheat flour was characterized by good appearance, acceptable elasticity, and better firmness and texture during cooking.

Depletion of Organophosphorus Pesticide Residues in Vegetables during Boiling Process
HUANG Yu1,PAN Kang-biao1,SHEN Juan1,TIAN Zi-hua1,LAI Jue-qiong2,WANG Can-nan2
2010, 31(3):  142-144.  doi:10.7506/spkx1002-6300-201003032
Asbtract ( 1495 )   HTML ( 0)   PDF (201KB) ( 379 )  
Related Articles | Metrics

Depletion of pesticide residues during boiling process is the important data for risk assessment. However, the related investigations have not been yet reported in China. The effect of boiling process on the residual level of acephate, dimethoate, triazophos, fenitrothion and chlorpyrifos in samples of cucumber, eggplant, round green pepper, Chinese cabbage, green vegetable, carrot, cabbage, celery, cauliflower and beans were determined by gas chromatography. Results showed that during boiling process different residual amounts of organophosphorus pesticides were observed in different species of vegetables. The depletion rate was ranged from 71.1% to 100% for acephate, 16.2% to 45.6% for dimethoate, 40.1% to 85.5% for triazophos, 25.8% to 61.5% for fenitrothion and 12.8% to 26.6% for chlopyrifos.

Correlation Analysis between Tenderness and Texture of Compound Oat Flour Sausages
XIA Jian-xin1,WANG Hai-bin1,*,XU Qun-ying2
2010, 31(3):  145-149.  doi:10.7506/spkx1002-6300-201003033
Asbtract ( 1431 )   HTML ( 0)   PDF (249KB) ( 494 )  
Related Articles | Metrics

Compound oat flour sausages were prepared by adding oat flour as the substitute for starch at various amounts such as 0, 8%, 11%, 14%, 17% and 20% (m/m, calculated on the basis of 100 of total sum of pork plus oat flour), respectively. The tenderness and texture of compound oat flour sausages was determined using tenderometer and texture analyzer, respectively. The correlation analyses between tenderness and texture parameters were conducted. Results indicated that the tenderness of compound oat flour sausages exhibited an increase with increasing addition amount of oat flour and the optimal addition amount of oat flour was 14%. Meanwhile, texture analysis results suggested that hardness of compound sausages with 14% addition amount of oat flour exhibited a significant difference with the control sausages (P<0.05). Moreover, the hardness of compound sausages with 17% or 20% oat flour exhibited a exceedingly significant difference with the control sausages (P < 0.01). Furthermore, the increasing amount of oat flour resulted in the increased chewiness. The chewiness of compound sausages with 14% or 17% oat flour revealed a significant difference with that of control sausages (P<0.05) and a highly significant difference at the evel of 20% oat flour (P< 0.01). Therefore, the tenderness of compound sausages is significantly correlated with hardness and chewiness (r=0.980, 0.984, respectively), but not correlated with elasticity and cohesiveness (r=-0.479, -0.700, respectively).

Objective Characterization and General Measurement Equation of Food Crispness
XIE Wei-ni,CHEN Jian-yang
2010, 31(3):  150-152.  doi:10.7506/spkx1002-6300-201003034
Asbtract ( 1614 )   HTML ( 2)   PDF (206KB) ( 778 )  
Related Articles | Metrics

Food crispness is so complex due to multiple factors that have been less explored as yet. Currently, no objective characterization and general measurement equation of food crispness have been available. In this study, vegetables and fruits were used as the subjects to establish the correlation between sensory evaluation and texture analysis profile for food crispness. The correlations between average sensory crispness and parameters including force, slope, area and area-distance ratio were analyzed. Results indicated that the highest correlation between slope and sensory crispness was observed and an evaluation model for food crispness was established based on this. Several kinds of biscuits were used to validate the evaluation model. The validation results demonstrate a good practical prospect of this model in predicting the crispness of vegetables and fruits as well as biscuits.

Antioxidant Activity of Extracts from Leontopodium leontopodioides
2010, 31(3 ):  153-159.  doi:10.7506/spkx1002-6300-201003035
Asbtract ( 1064 )   HTML ( 2)   PDF (520KB) ( 487 )  
Related Articles | Metrics

In this study, water and ethanol extracts from Leontopodium leontopodioides were confirmed to be polyphenols, which was mainly composed of flavonoids. The antioxidant activities of the water and ethanol extracts were evaluated by in vitro total reducing power, superoxide anion, hydroxyl and sodium nitrite free radical scavenging capacity, lipid peroxidation inhibition, and nitrosamine synthesis blocking assays. Both the extracts exhibited strong reducing power and scavenging effect against free radicals. Above 60% inhibition rate against lipid peroxidation was observed in the ethanol extract. Moreover, both the extracts revealed strong capacity to scavenge sodium nitrite and block nitrosamine synthesis. The maximum scavenging rate of the water extract against sodium nitrite was 77.7% and the blocking rate of the ethanol extract against nitrosamine synthesis 98%.

Optimization of Fermentation Medium for Thermostable Cellulase Production by Engineered Bacteria Using Quadratic Regression Orthogonal Composite Design Coupled with Integrated Correlation Coefficient Analysis
DU Rui-qing1 LU Wen-ping2,* WANG Li1
2010, 31(3):  160-164.  doi:10.7506/spkx1002-6300-201003036
Asbtract ( 1159 )   HTML ( 1)   PDF (446KB) ( 403 )  
Related Articles | Metrics

Objective: To provide reference for large-scale production of thermostable cellullase by engineered bacteria fermentation. Methods: The optimal fermentation medium of recombinant Escherichia coli obtained from Clostridium thermocellum for the production of thermostable cellullase were investigated using quadratic regression orthogonal composite design coupled with integrated correlation coefficient analysis, where four factors and their relative importance were analyzed. Results: The quadratic regression equation between four experimental factors and cellulose activity was presented as follows: Y2 = 45.858-1.653Z1-1.258Z2Z3-2.012Z12-1.499Z22-1.415Z32-1.719Z42. Variance analysis exhibited a significant difference. The optimal fermentation medium of the recombinant strain for the production of thermostable cellullase consisted of 15.9 g/L lactose, 10 g/L wheat bran, 15 g/L ammonium sulfate, 5 g/L corn syrup and 1.0 g/L calcium carbonate. The theoretical cellullase activity was 46.19 U/mL after 4 h of induction time. However, the actual cellullase activity was 70.78 U/mL. Integrated correlation coefficient analysis showed the importance of four factors according to the following order of inducer X1 (lactose)>nitrogen source X3 (ammonium sulfate and corn syrup)>calcium concentration X4 (calcium carbonate)>carbon source X2 (wheat bran). The indirect effects from cross-interaction on cellulase activity were all larger than the direct effects. Conclusion: The combinatorial application of integrated correlation coefficient and quadratic regression orthogonal composite design exhibits a complementary effect, which benefits the optimization of fermentation medium of recombinant Escherichia coli obtained from Clostridium thermocellum for the production of thermostable cellullase.

Optimizing Fermentation Conditions of Lactobacillus helveticus for Preparing ACE Inhibitory Peptides from Whey Protein
LU Hui-hui1 PAN Dao-dong1,2,* LU Li-shuang1
2010, 31(3):  165-169.  doi:10.7506/spkx1002-6300-201003037
Asbtract ( 1542 )   HTML ( 0)   PDF (408KB) ( 414 )  
Related Articles | Metrics

In this work, the effect of fermentation conditions on the preparation of ACE (angiotensin converting enzyme) inhibitory peptides from whey protein fermented by Lactobacillus helveticus was investigated. The optimal fermentation conditions were determined using single factor method combined with response surface methodology as follows: 17.52 h of fermentation time, 37.07 ℃ of fermentation temperature, and 114.1 g/L whey protein. The inhibitory activity of anti-ACE peptides obtained under the optimal conditions was up to 89.337%.

Enzymatic Properties ofβ-1,3-1,4-Glucanase from Recombinant Industrial S. cerevisiae
ZHANG Qiang1,2 CHEN Qi-he1 HE Guo-qing1
2010, 31(3):  170-172.  doi:10.7506/spkx1002-6300-201003038
Asbtract ( 1470 )   HTML ( 0)   PDF (318KB) ( 379 )  
Related Articles | Metrics

Enzymatic properties of β-1,3-1,4-glucanase secreted by recombinant S. cerevisiae strain SC-βG was examined using Congo-Red method and compared with the native β-1,3-1,4-glucanase from original strain B. subtilis. Results showed that obvious differences in enzymatic properties of β-1,3-1,4-glucanase from S. cerevisiae strain SC-βG and original strain B. subtilis except substrate specificity were observed. The optimal reaction temperature was 35 ℃ for recombinantβ-1,3-1,4-glucanase and 55 ℃ for native β-1,3-1,4-glucanase. As for thermal stability, recombinantβ-1,3-1,4-glucanase remained 63.4% activity after 40 ℃ heat treatment for 20 min and 45.9% activity after 70 ℃heat treatment; in contrast, the nativeβ-1,3-1,4-glucanase was stable below 50 ℃ and its activity exhibited a significant loss after heat treatment at 60 ℃. Moreover, the optimal reaction pH for both enzymes also exhibited an obvious difference, such as pH 5.0 for recombinant β-1,3-1,4-glucanase and pH 6.5 for native β-1,3-1,4-glucanase. Similarly, the optimal pH for stability of both enzymes was 5.5 for recombinant β-1,3-1,4-glucanase and 7.0 for native β-1,3-1,4-glucanase. Therefore, the optimal reaction conditions of recombinant β-1,3-1,4-glucanase are closer to beer brewing conditions so that this enzyme should reveal better effect on beer brewing.

Immobilization of Recombinant Chitinase with Two Functional Magnetic Carriers
FENG Li1,2 YAN Rui-xiang2 FENG Chun-yu2 LIN Yan1,2 LI Xi-hong1,*
2010, 31(3):  173-176.  doi:10.7506/spkx1002-6300-201003039
Asbtract ( 1430 )   HTML ( 2)   PDF (408KB) ( 460 )  
Related Articles | Metrics

Two kinds of functional magnetic carriers (A-type and P-type) were prepared and used for the immobilization of recombinant chitinase. A-type carrier was prepared by 3-aminopropyltriethoxysilane (APTES) and Fe3O4 magnetic microsphere. P-type carrier was prepared by co-polymerization of glycidyl methacrylate (GMA) on the surface of Fe3O4 magnetic microsphere in the presence of polyethylene glycol. Results indicated that P-type carrier had higher protein loading capacity and purification fold compared with A-type carrier, which were 1689.74 mg/g and 6.8013, respectively. The activity of immobilized recombinant chitinase onto P-type carrier could maintain 69.66% at 4 ℃ for 10 days. The activity of immobilized recombinant chitinase onto P-type carrier remained more than 44 % of original activity after being repeatedly used 7 times.

Cloning and Expression of Maize Transglutaminase in Escherichia coli
QIN Lan-xia1 WANG Li2 ZHANG Lan-wei3,*
2010, 31(3):  177-181.  doi:10.7506/spkx1002-6300-201003040
Asbtract ( 1311 )   HTML ( 0)   PDF (465KB) ( 482 )  
Related Articles | Metrics

In this study, total RNA was extracted from young leaves of maize. Reverse transcription PCR (RT-PCR) method was used to obtain full-length transglutaminase (TGase) gene. The amplified fragment was sequenced to have 1605 bp. The gene consisted of 535 amino acid residues with a calculated molecular mass of 60.9 kD. It was identical to the published TGase gene (GenBank NO. AJ421525). This gene fragment was cloned into pET-28a expression vector. The pET-28a-TGase was transformed into E. coli Rosetta (DE3) and expressed in E. coli cells with the induction of 1 mmol/L IPTG. According to quantitative analysis, the expression amount of this protein was approximately 15% of total protein. Western-blot analysis confirmed that this protein was a His-tag recombinant protein. After the purification by Ni2+-NTA affinity chromatography, the purified protein exhibited high purity and one single band was shown in SDS-PAGE. The TGase activity was up to 16 U/mg after purification.

Effect of Dissolved Oxygen on Production of L-cysteine Synthetase by Pseudomonas sp. TS1138
HUAI Li-hua1 CHEN Ning2
2010, 31(3):  182-184.  doi:10.7506/spkx1002-6300-201003041
Asbtract ( 1294 )   HTML ( 0)   PDF (286KB) ( 306 )  
Related Articles | Metrics

Pseudomonas sp. TS1138 has potential to produce L-cysteine synthetase through asymmetrical hydrolysis of DL-2-amino-Δ2-thiazoline-4-carboxylic acid (DL-ATC). The effect of dissolved oxygen level on the production of L-cysteine synthetase was investigated in shake flasks or 7 L bioreactor. Results indicated that the cell growth and the production of L-cysteine synthetase were inhibited at low dissolved oxygen level. Although cell growth was improved at the high dissolved oxygen level, the inhibition against production of L-cysteine synthetase was still observed in shake flasks. In 7 L bioreactor, dissolved oxygen concentration controlled at more than 30% was helpful for improving the cell growth and the production of L-cysteine synthetase through regulating agitation rate and air flow rate during the middle and late stage.

Enzymatic Properties of Chymosin from Mucor pusillus
GAO Wei-dong1,2 GAN Bo-zhong1,* DING Fu-jun2 ZHANG Yu-ping2 ZHU Xiong-ying2 JI Yin-li2
2010, 31(3):  185-188.  doi:10.7506/spkx1002-6300-201003042
Asbtract ( 1453 )   HTML ( 1)   PDF (389KB) ( 327 )  
Related Articles | Metrics

To study enzymatic properties of chymosin from Mucor pusillus (HL-1), the optimal temperature, pH and thermal stability of chymosin were investigated. Along with this, the effects of metal ions, chemical materials, calcium ions and enzyme amount on the activity of the enzyme were examined, and the proteolytic activity, relative molecular weight, Km and Vm of the enzyme were measured. The optimal reaction temperature and pH of the enzyme was 60 ℃ and 5.5. Incubation at 65 ℃ for 5 min resulted in 95% loss of enzyme activity. Calcium ion, an enzyme activator, could improve the enzyme activity in a concentration-dependent manner; in contrast, potassium ion was an inhibitor of the enzyme. Sodium chloride did not affect the enzyme activity, but SDS led to the severe inactivation of the enzyme. Meanwhile, a negative relationship between enzyme amount and reaction time was observed. The proteolytic activity, relative molecular mass, Km and Vm of the enzyme were 485.3 U/g, 42000, 0.0238 mol/L and 1.1227 mg/min, respectively.

Optimization of Fermentation Medium for Production of Antibacterial Peptides by Bacillus subtilis BSD-2
ZHANG Lei1,2 ZHANG Duo3 ZHANG Li-ping1,* CHENG Hui-cai1 HU Rui-ping1,2 ZHANG Gen-wei1
2010, 31(3):  189-192.  doi:10.7506/spkx1002-6300-201003043
Asbtract ( 1535 )   HTML ( 2)   PDF (358KB) ( 427 )  
Related Articles | Metrics

Plackett-Burman design was used to evaluate the importance of fermentation medium factors of Bacillus subtilis BSD-2 affecting the inhibitory zone diameter of produced antibacterial peptides. Subsequently, 7 steepest ascent experiments involving 3 most important factors (i.e., peptone, starch and soybean meal) were conducted for approaching their optimal response region. Finally, the optimal fermentation medium formula was obtained by optimizing the most important factors using central composite design combined with response surface methodology. Results indicated that the optimal fermentation medium formula consisted of 14.29 g/L peptone, 14.07 g/L amylum, 6.49 g/L soybean power, 2.0 g/L CaCO3 and 1.0 g/L MgSO4. There was a 1.77-fold increase in the yield of antibacterial peptides obtained using the optimal fermentation medium, compared with that before optimization.

Fermentation of Passion Fruit Pomace for Dietary Fiber Preparation
MAO Hui-jun1 WEN Liang-juan1,* LI Ying-jun1 ZHANG Yuan-chun1 LIANG Yu2 LI Geng-feng2
2010, 31(3):  193-197.  doi:10.7506/spkx1002-6300-201003044
Asbtract ( 1198 )   HTML ( 0)   PDF (432KB) ( 368 )  
Related Articles | Metrics

Passion fruit pomace, a by-product from passion fruit juice processing, was fermented with a mixed strain of Lactobacillus bulgaricus and Streptococcus thermophilus to prepare dietary fiber. To maximize soluble to total dietary fibre ratio (SDF/TDF ratio), the optimal fermentation process of passion fruit pomace was investigated using single factor method combined with orthogonal array design. In addition, the physico-chemical properties of dietary fiber obtained were analyzed. Results showed that the optimal fermentation conditions were determined as follows: 5% mixture of Lactobacillus bulgaricus and Streptococcus thermophilus, 1:10 of solid/liquid ratio, 33 ℃ of fermentation temperature and 21 h of fermentation time. The soluble dietary fiber (SDF) content was up to (29.01±0.41)% under the optimal fermentation conditions, which was higher than that obtained by chemical methods. Therefore, this fermentation method yields passion fruit dietary fibre with better water-holding capacity compared with chemical methods, but there is no obvious difference in expansion capacity.

Purification and Enzymatic Properties of Inulinase from Kluyveromyces marxianus
JIU Min WANG Lun-ji
2010, 31(3):  198-202.  doi:10.7506/spkx1002-6300-201003045
Asbtract ( 1476 )   HTML ( 1)   PDF (420KB) ( 753 )  
Related Articles | Metrics

Crude extracellular inulinase from Kluyveromyces marxianus was purified through sequential steps of ultrafiltration, DEAE-cellulose anion exchange chromatography and SephadexG-100 gel filtration to obtain two components, designated as Exo I and Exo II inulinase. The molecular weight of Exo I inulinase was 85 kD. The optimal reaction pH and temperature of Exo I were 4.0 and 60 ℃, respectively. In addition, Mn2+and Mg2+ could improve the activity of Exo I inulinase; in contrast, Cu2+ and Fe2+ exhibited a strong inhibition effect on Exo I inulinase activity. Enzymatic hydrolysates of inulin by Exo I inulinase were fructose and a small amount of glucose.

Fermentation of Lixivium of Distiller’s Grains for Bacterial Cellulose Preparation
SHEN Jin-peng LUO Qing-ping DUAN Xiao-hui PEI Chong-hua*
2010, 31(3):  203-206.  doi:10.7506/spkx1002-6300-201003046
Asbtract ( 1529 )   HTML ( 0)   PDF (421KB) ( 302 )  
Related Articles | Metrics

Bacterial cellulose (BC) was prepared from lixivium of three distiller’s grains fermented by Acetobacter xylinum. Results showed that the lixivium from three distiller’s grains was rich in nutrients. However, the lixivium from distiller’s grains with rice husk was more suitable to produce BC. The yield of BC was 2.7 g/L when the lixivium with the addition of 2% sucrose was conducted to static fermentation at pH 5.0 and 30 ℃ for 15 days. The pH exhibited an increase trend after fermentation. The structural characteristics of BC were demonstrated using scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectrum and X-ray diffraction (XRD) with the diameter between 20 nm and 100 nm.

Isolation and Identification of Mycetes from Viili
LIU Xu-chuan1 WANG Yong1 LUO Cheng2 LIU Yong1,*
2010, 31(3):  207-208.  doi:10.7506/spkx1002-6300-201003047
Asbtract ( 1334 )   HTML ( 0)   PDF (293KB) ( 347 )  
Related Articles | Metrics

In order to understand the fermentation strain composition and major polysaccharides-producing strains in Viili, isolated strains from cultivated Viili were used for milk fermentation. According to morphological observation, polysaccharides are mainly produced by Geotrichum candidum Lk, which belongs to mycetes.

Contamination, Virulence Genes and Drug Resistance of Vibrio parahaemolyticus from Aquatic Products
AN Xiu-hua NING Xi-bin* LI Tao
2010, 31(3):  209-212.  doi:10.7506/spkx1002-6300-201003048
Asbtract ( 1732 )   HTML ( 1)   PDF (392KB) ( 382 )  
Related Articles | Metrics

Added together, 105 strains of Vibrio parahaemolyticus (Vp) were isolated from 273 aquatic products in three species collected from farmers’ markets in Shanghai. The average Vp contamination rate of aquatic products was 38.46%. In addition, the Vp contamination rates of crustacean, shellfish and fish were 50.96%, 27.12% and 15.79%, respectively. A significant difference was observed in three species of aquatic products (P<0.01). Only tlh gene was detected in isolated Vp strains through multiplex-PCR, while no tdh gene and trh gene were detected. These isolated Vp strains exhibited strong resistance to 10 kinds of antibiotics including ceftriaxone, nalidixic acid and norfloxacin according the evaluation by K-B method. Some of these isolated Vp strains exhibited 69.50% resistance to ampicillin and 12.38% resistance to amoxicillin. Moreover, the analysis of plasmid DNA from 105 isolated strains revealed that seven isolated strains harbored 1-3 plasmids with size ranging from 1 to 24 kb. In analyzing fingerprinting images of plasmids and drug resistant types, no direct relationship between drug resistance and plasmid size or amount was observed. These results suggest that the drug resistance to these antibiotics mainly results from chromosomal mutation of Vp strains.

Nutrition & Hygiene
Hepatoprotective Effect of Ganoderma lucidum Peptides against Alcohol-induced Liver Injury in Mice
HE Hui,SHI Yan-ling,XU Shu-fen,ZHANG Sheng,GUO Hui
2010, 31(3):  213-216.  doi:10.7506/spkx1002-6300-201003049
Asbtract ( 1431 )   HTML ( 0)   PDF (209KB) ( 519 )  
Related Articles | Metrics

The hepatoprotective effect of Ganoderma lucidum peptides (GLP) against alcohol-induced liver injury in mice was investigated. Totally 60 mice were randomly divided into 6 groups of 10 mice each: normal group, alcohol model group, tioronin positive control group and GLP treatment groups. The mice in GLP groups were daily administered GLP via gavage tubes at doses of 60, 120 mg/kg bw and 180 mg/kg bw, respectively. Positive control group was administered tioronin at the dose of 50 mg/kg bw and other groups were administered saline at the identical volume. At 3 h postadministration, mice in all other groups except normal group were induced with 50% alcohol at 16 mL/ kg bw administration level to create a liver injury model, while mice in normal group were administered normal saline at the same volume. The indexes of liver and spleen were calculated. The alanine transaminase (ALT), aspartate transaminase (AST) and triglyceride (TG) level in serum, as well as malondialdehyde (MDA) and glutathione (GSH) levels, and superoxidedismutase (SOD) activity in liver were measured. GLP treatment at the dose of 60 mg/kg bw significantly reduced the elevation of AST, ALT, MDA and TG (P < 0.01), and significantly inhibited the decrease of SOD activity and GSH levels (P<0.05-0.01) in mice suffering from liver injury. In conclusion, GLP treatment at the dose of 60 mg/kg bw has a significant hepatoprotective effect against alcohol-induced liver injury in mice and a better hepatoprotective effect of GLP treatment at the dose of 180 mg/kg bw was achieved compared to tioronin treatment at the dose of 50 mg/kg bw.

Digestibility of Coarse Cereal Starch in Piglets
ZHANG Zhen-zhen1,2,YIN Fu-gui2,3,HUANG Ju2,YIN Yu-long1,2,*,RUAN Zheng1,DAI Zhi-kai1,LIAO Chun-long1
2010, 31(3):  217-219.  doi:10.7506/spkx1002-6300-201003050
Asbtract ( 1418 )   HTML ( 0)   PDF (164KB) ( 344 )  
Related Articles | Metrics

Piglets of 60 days old were used as the animal model to evaluate in vivo apparent digestibility of starch of different coarse cereals such as taro, potato, Chinese yam and cassava. Results indicated that starch content varied in different species of coarse cereals. The apparent digestibility of taro and cassava starches in ileal digesta was significantly higher (P<0.05) than that of potato and Chinese yam starches. The apparent digestibility of starches of all the coarse cereal species in faeces reached up to 99%. These investigations suggest that taro and cassava starches could supply piglets more glucose when digested in small intestine due to higher digestibility. Higher digestibility of potato and Chinese yam starches in feces could be resulted from the co-fermentation of microorganisms in hindgut of piglets.

Hawthorn Flavonoid Extract: Antioxidant Activity and Growth Inhibition Effect on Cancer Cells
LIU Jia1,David Glen POPOVICH2,JING Hao1,*
2010, 31(3):  220-223.  doi:10.7506/spkx1002-6300-201003051
Asbtract ( 1305 )   HTML ( 4)   PDF (414KB) ( 650 )  
Related Articles | Metrics

Objective: To study antioxidant activity of hawthorn (Crataegus pinnatifida Bunge) flavonoid extract (HFE) as well as its growth inhibition effect on Hep-G2 and Caco-2 cells. Methods: Total flavonoid content was determined by NaNO2-Al(NO3) 3 colorimetric method. Antioxidant activity was evaluated by 2,2’-azinobis(3-ethylbenzothiazoline-6-suslfonic acid (ABTS) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assays. Cell growth inhibition effect of HFE was assessed by MTT assay. Results: Flavonoids were dominant in HFE with a content of 98% (calculated on the basis of dry weight). Both ABTS and DPPH scavenging capacities exhibited an increase with increasing HFE concentration. The EC50s of HFE was 88μg/mL and 112μg/mL in ABTS and DPPH assays, respectively; while those of Trolox were 111μg/mL and 118μg/mL. Cell growth of Hep-G2 and Caco-2 cells were remarkably inhibited by HFE in a dose-dependent manner. Whereas, HFE had stronger growth inhibition effect against Hep-G2 cells than against Caco-2 cells. The IC50s of HFE were 115μg/mL and 376μg/mL for Hep-G2 and Caco-2 cells, respectively. Conclusion: HFE has high content of flavonoids, strong antioxidant activity, and strong inhibitory effect against cancer cell growth. Therefore, it has a promising potential as an effective natural antioxidant and an anticancer functional component.

Pathological Roles and LC-MS/MS Determination of Salbutamol
GU Li-li1,LI Fei1,NIU Ying-hao1,GE Lan1,ZHANG Yan2,ZHAO Bao-hua1,*
2010, 31(3):  224-229.  doi:10.7506/spkx1002-6300-201003052
Asbtract ( 1313 )   HTML ( 0)   PDF (876KB) ( 482 )  
Related Articles | Metrics

A pathological mouse model induced by salbutamol was established for evaluating its pathological roles. HE staining of frozen sections showed serious damages in liver tissues, which exhibited scattered distribution rather than radial-arranged central veins in liver leaflets and obvious apoptotic bodies in liver tissues. Simultaneously, coagulation necrosis was also observed in heart tissues due to the coagulation of a large number of myocardial fibers. Moreover, the liver of pathological mice was used as a positive sample to detect its enzymatic hydrolysis using LC-MS/MS. Results indicated that β -D-glucuronic glucosidase or arylsulfatase was the effective enzyme for salbutamol determination and the determination results obtained using enzymatic hydrolysis was three times as high as those obtained without using enzymatic hydrolysis.

Effect of Lonicera caerulea Anthocyanin on Lipid Metabolism and Antioxidant Function in High Fat Diet-induced Obese Rats
JIAO Yan1,WANG Zhen-Yu1,2,*
2010, 31(3):  230-234.  doi:10.7506/spkx1002-6300-201003053
Asbtract ( 1468 )   HTML ( 0)   PDF (207KB) ( 522 )  
Related Articles | Metrics

Objective: To study the effect of anthocyanin extracted from Lonicera caerulea residue (LCRA) on lipid metabolism and antioxidant function in high fat diet-induced obese rats. Methods: Rats were divided into 5 groups, inluding normal control group, obesity model group and LCRA low-, medium- and high-dose groups treated with LCRA at doses of 4.0, 40.0 mg/kg bw·d and 120 mg/kg bw·d. Normal control and obesity model groups were fed normal saline at the dose of 1.2 g/kg bw·d for 28 consecutive days. After administration, body and liver weight, body fat percentage, total triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), activities of HL, LPL, LPS, SOD and GSH-Px, and MDA content in liver were measured. Results: Compared with obesity model group, LCRA treated groups exhibited a significant reduction in serum lipid level and MDA content in liver and a significant increase in the activities of HL, LPL, LPS, SOD and GSH-Px in liver. Conclusion: LCRA can improve lipid metabolism in high fat diet-induced obese rats, which reveals strong functions for reducing peroxidative liver injury and preventing arteriosclerosis.

Effect of Extract from Medicago sativa L. on Weight Loss in Rats with Nutritional Obesity
LI Lan-fang,LI Guo-feng,HAO Na,ZHANG Qin-zeng,XIE Li-jun,SHANG Tao,LI Li-ping,WANG Wei
2010, 31(3):  235-238.  doi:10.7506/spkx1002-6300-201003054
Asbtract ( 1464 )   HTML ( 2)   PDF (435KB) ( 420 )  
Related Articles | Metrics

Objective: To investigate the effect of extract from Medicago sativa L. (MSE) on weight loss in rats with nutritional obesity. Methods: Sixty weaning male rats were randomly divided into 6 groups, including control group, obesity model group, positive control group administered sibutramine and MSE treatment groups at the doses of 1.80, 0.90 g/kg bw and 0.45 g/kg bw. The rats in control group were fed normal diet and those in other groups were fed nutritional diet and administered experimental drugs once a day for 70 consecutive days. All rats were weighed twice a week. Body weight, body fat percentage, Lee’s index, contents of TC and TG in serum and liver, albumin, blood sugar and hemoglobin were determined at the end of experiments. Results: MSE exhibited a significant reduction effect on body weight, fat tissue around testicle and kidney, body fat percentage and Lee’s index. Meanwhile, MSE also resulted in a significant decrease in total cholesterol and an inhibition effect on growth of fat cells around the genitals in obese rats. However, no obvious change of blood sugar, albumin, TG and hemoglobin was observed in obese rats treated with MSE. Conclusion: MSE has a function of weight loss in obese rats without side effects, which is worthy of in-depth development.

Hypoglycemic Effect of Water Extract from Hubei Rubus chingii Hu Leaves on Reducing Blood Sugar in Alloxan-induced Diabetic Mice and Human Adults with High Blood Sugar
FAN Bo-lin,GONG Chen-rui,SUN Fan-zhong,TIAN Hui,TIAN Jie,WANG Yu-e,ZHANG Qi-ai,LI Xin-lan,
2010, 31(3):  239-242.  doi:10.7506/spkx1002-6300-201003055
Asbtract ( 1662 )   HTML ( 0)   PDF (184KB) ( 470 )  
Related Articles | Metrics

Objective: To study the hypoglycemic effect of water extract from Hubei Rubus chingii Hu leaves in alloxan-induced diabetic mice and adults with high blood sugar. Methods: In animal trails, diabetic mice induced by tail vein injection of alloxan were administered water extract from Hubei R. chingii Hu leaves at doses of 0.40, 0.80 g/kg bw and 1.20 g/kg bw for 30 consecutive days. Fasting blood sugar and post-glucose blood sugar in mice were measured. In human trials, 106 patients with type II diabetes were recruited and randomly divided into two groups, namely experimental and control groups. The experiment group was administered capsules made of water extract from Hubei R. chingii Hu leaves for 30 consecutive days, while the control group was given placebo. Fasting blood sugar and 2 h post-meal blood sugar were measured. Blood biochemical index, liver function and kidney function were measured to evaluate the safety of water extract from Hubei R. chingii Hu leaves. Results: In animal trials, compared with the control group, fasting blood sugar of mice administered the water extract at doses of 0.80 g/kg bw and 1.20 g/kg bw exhibited a significant decrease. In human trials, diabetic symptoms in the experimental group were significantly attenuated. Compared to the pre-administration experimental group, fasting blood sugar and 2 h post-meal blood sugar in the post-administration experimental group revealed the reductions of 16.9% and 16.0%, respectively. Meanwhile, there were extremely significant differences between the post-administration experimental group and pre-administration one or the control group. Conclusion: Water extract from Hubei R. chingii Hu leaves has an obvious hypoglycemic effect in diabetic mice and human adults with high blood sugar.

Effect of Dioscorea opposita on Learning and Memory Ability in Mice
WANG Li-juan1,2,LI Jie2,ZHANG Yun2,WANG Qing-yan3
2010, 31(3):  243-245.  doi:10.7506/spkx1002-6300-201003056
Asbtract ( 1729 )   HTML ( 0)   PDF (176KB) ( 292 )  
Related Articles | Metrics

Acquired dysmnesia and memory disorder models caused by scopolamine and alcohol, respectively, were used to compare the effects of Dioscorea opposita and piracetam on learning and memory function in mice by maze and step-down methods. Results indicated that aqueous extract of Dioscorea opposita could obviously improve learning and memory ability in mice. Compared with model group, groups treated with the extract at doses of 20 g /kg and 30 g/kg or piracetam exhibited fewer error times, longer latent period and shorter total time of electronic shock (0.01 < P < 0.05). While no significant difference between Dioscorea opposite-treated and piracetam-treated groups was observed (P > 0.05). Therefore, Dioscorea opposita can obviously improve the ability of learning and memory in mice. However, further investigations on the related mechanisms are needed.

Effect of Soluble Polysaccharide PGEB-3-H from Gastrodia elata Blume on Scopolamine-induced Learning and Memory Disorders in Mice
MING Jian1,2,ZENG Kai-fang1,2,WU Su-rui4,FU Ai-ling3,ZHAO Guo-hua1,2,GUI Ming-ying4,CHEN Zong-dao1,2,*
2010, 31(3):  246-249.  doi:10.7506/spkx1002-6300-201003057
Asbtract ( 1547 )   HTML ( 1)   PDF (321KB) ( 379 )  
Related Articles | Metrics

Objective: To investigate the effect of PGEB-3-H, a soluble polysaccharide from Gastrodia elata Blume, on scopolamine-induced learning and memory disorders in mice. Methods: Learning and memory ability in mice were evaluated by Morris water maze. Acetylcholine and malondialdehyde (MDA) content were measured in brain tissues of mice. Results: Compared with model group, the time for passing water maze of mice treated with PGEB-3-H at doses of 100, 200 mg/kg bw·d and 400 mg/kg bw·d (namely, PGEB-3-H low-, medium- and high-dose groups, respectively) was obviously shorter in a dosedependent mode, and there was an extremely significant difference between PGEB-3-H high-dose group and model group (P <0.01). Moreover, PGEB-3-H high-dose group exhibited higher acetylcholine content in brain tissues when compared to normal saline group or positive control group. In addition, MDA content in brain tissues of PGEB-3-H medium-dose group exhibited a significant decrease (P <0.05). Conclusion: PGEB-3-H can improve scopolamine-induced learning and memory disorders in mice, and its mechanism may be due to the increase of acetylcholine content in brain tissues.

Effect of Honeybee Pupae Peptide-rich Protein Powder on Immune Function, Blood Glucose and Blood Lipid in Rats
SHENG Sheng,ZHOU Jie*,SHEN Yong-zhou,ZHANG Jia,ZHU Feng-qiao
2010, 31(3):  250-252.  doi:10.7506/spkx1002-6300-201003058
Asbtract ( 1372 )   HTML ( 0)   PDF (178KB) ( 709 )  
Related Articles | Metrics

Fifty 3-week-old SD rats were selected and randomly divided into 2 groups, namely treatment and control groups administered honeybee pupae peptide-rich protein powder and honeybee pupae protein powder for 4 consecutive weeks. Results showed that the contents of serum IgG, IgA and spleen index of rats treated with peptide-rich protein powder exhibited a significant increase (P<0.05), whereas no effect on serum IgM content and thymus index. In addition, compared with the control group, an extremely significant decrease in blood glucose (P < 0.01), a significant decrease in density lipoprotein cholesterol (LDL-C) content (P <0.05), and an increase in serum triglyceride (TG) content and density lipoprotein cholesterol (HDL-C) content (P < 0.05) were observed in rats treated with peptide-rich protein powder. However, peptide-rich protein powder had no significant effect on the contents of serum free fatty acids (FFA) and serum total cholesterol (TC). Therefore, peptide-rich protein powder can enhance immune function, decrease blood glucose, and prevent the occurrence of atherosclerosis.

Regulatory Effect of Supernatant of Bacillus natto-fermented Rice Bran on Intestinal Tract System in Mice
QI Hong-bing1,CHEN Jun2
2010, 31(3):  253-257.  doi:10.7506/spkx1002-6300-201003059
Asbtract ( 1328 )   HTML ( 0)   PDF (278KB) ( 395 )  
Related Articles | Metrics

Objective: To exploit the resource of rice bran and investigate the regulation role of supernatant of Bacillus nattofermented rice bran (SBRB) for intestinal tract system in mice. Methods: The culture supernatant of Bacillus natto in rice bran fermentation medium was co-cultured with Bacillus bifidus. Mice were treated with SBRB via a gavage tube and the quantity of normal flora of intestinal tract in mice was detected. Results: Individual Bacillus natto could not promote the growth of Bacillus bifidus under anaerobic environment in vitro. However, both SBRB and aqueous extract of rice bran (AERB) could promote the growth of Bacillus bifidus by 65.2% and 17.8%, respectively. After enzymatic digestion by pepsin and trypsin, 51.6% promotion capacity of SBRB was remained. Similarly, the growth promotion of anaerobic bacteria and growth inhibition of aerobic bacteria were also observed in the intestinal tract in mice treated with SBRB. Individual application of Bacillus natto and its fermentation broth exhibited a regulatory effect on normal flora of intestinal tract in mice. In additions, a synergistic effect of combinatorial application on normal flora of intestinal tract in mice was also observed. Conclusion: SBRB has the function for regulating intestinal tract flora and has a promising potential to be used as synbiotic preparation.

Preventive Effect of Chaenomeles Fruits on Non-alcoholic Steatohepatitis in Mice
LI Bin1,LIU Chao-qi1,*,SHI Ji-jing1,DONG Man-man2,LI Meng-pei2,LIU Qian2,QIN Xiao-lin1,LU Bai-rui1
2010, 31(3):  258-261.  doi:10.7506/spkx1002-6300-201003060
Asbtract ( 1934 )   HTML ( 0)   PDF (291KB) ( 428 )  
Related Articles | Metrics

Objective: To investigate the preventive effect of Chaenomeles fruits on non-alcoholic steatohepatitis (NASH) in mice. Methods: NASH model was established by high fat diet feeding combined with hypodermic injection at low dose of CCl4. NASH model group fed high fat diet containing Chaenomeles fruits for 5 consecutive weeks was served as Chaenomeles fruitsintervened group, while the mice in control group were fed normal diet. At the end of experiments, all the mice were sacrificed to analyze ALT, AST, TG and CHO levels in serum. Pathological changes of hepatic tissues were observed under microscope and mRNA expression of genes such as TGF-β, PD-L1, TLR-2, TLR-4 and IL-1β in hepatic tissues was detected by the real time RT-PCR technique. Results: Compared to normal mice, ALT, TG and CHO levels in serum exhibited an obvious increase in NASH mice and a significant reduction in Chaenomeles fruits-intervened NASH mice (P<0.05). Hepatocyte swelling, as well as neutrophilic infiltration and hepatocyte ballooning exhibited a decrease in Chaenomeles fruits-intervened NASH mice. Meanwhile, a significant decrease in hepatic TLR-2, TLR-4, IL-1β, TGF-β and PD-L1 were also observed in Chaenomeles fruits-intervened NASH mice. Conclusion: Chaenomeles fruits have a significant preventive effect on non-alcoholic steatohepatitis in mice, which is achieved by regulating TLR and death receptor expression and the secretion of inflammatory cytokines.

Antioxidant Function of Black Soybean Peptide in D-Galactose-induced Senescent Mice
WANG Chang-qing1,REN Hai-wei2,WANG Hai-feng1,LIU Jia-lu1,LU Peng1
2010, 31(3):  262-266.  doi:10.7506/spkx1002-6300-201003061
Asbtract ( 1455 )   HTML ( 0)   PDF (312KB) ( 291 )  
Related Articles | Metrics

In order to investigate the antioxidant function of black soybean peptide (BSP) in D-galactose-induced senescent mice, fifty Kunming mice were divided into five groups, designated as control group, oxidative injury model group, VC positive control group, and BSP high- and low-dose groups. Except the control group, all other groups were intraperitoneally injected with D-galactose solution at the daily dose of 400 mg/kg bw·d for 56 successive days. At the same time, BSP-treated mice were administered BSP by gavage at the daily dose of 400 mg/kg bw·d and 800 mg/kg bw·d, respectively. Malondialdehyde (MDA) content, glutathione peroxidase (GSH-Px) activity and lipofuscin (LPF) content in serum or in liver were assayed. Moreover, the indexes of spleen, kidney, liver and thymus gland were also determined. Results showed that thymus index, spleen index and MDA content exhibited a significant decrease. While GSH-Px activity revealed a significant decrease both in serum and in liver of oxidative injury mouse model. Both 400 mg/kg bw·d and 800 mg/kg bw·d BSP administrations resulted in a significant increase in thymus index, spleen index and GSH-Px activity in serum or liver and a significant decrease in MDA content. Furthermore, BSP at the dose of 800 mg/kg bw·d also resulted in a significant decrease in LPF content in liver. Therefore, BSP has obvious antioxidant activity in vivo due to its free radical scavenging activity and improved immune organ index for accomplishing anti-aging effect in a dose-dependent mode.

Research Progress in Antioxidant Activity of Anoxygenic Photosynthetic Bacteria
XU Ming-shuang,SHENG Ji-ping,SHEN Lin*
2010, 31(3 ):  267-270.  doi:10.7506/spkx1002-6300-201003062
Asbtract ( 1336 )   HTML ( 0)   PDF (200KB) ( 775 )  
Related Articles | Metrics

Anoxygenic photosynthetic bacteria not only are abundant in nutritional components and bioactive materials, but also possess the functions of biological nitrogen fixation, production of hydrogen and degradation of toxic substances. Therefore, anoxygenic photosynthetic bacteria have been gain tremendous attention. In this paper, taxonomy, antioxidant mechanisms and applications of anoxygenic photosynthetic bacteria are reviewed. Meanwhile, the current problems are also discussed.

Research Progress in Methods for Geographical Origin Traceability of Agricultural Products
ZHANG Xiao-yan1,2,SU Xue-su3,*,JIAO Bi-ning1,2,FU Chen-mei2,CAO Wei-quan3
2010, 31(3):  271-278.  doi:10.7506/spkx1002-6300-201003063
Asbtract ( 1455 )   HTML ( 3)   PDF (266KB) ( 891 )  
Related Articles | Metrics

The geographical origin traceability of agricultural products, an important part of traceability system, is effective in protecting the quality and safety of agricultural products. Using physical, chemical and biological methods, geographical origin of agricultural products can be analyzed according to specific indexes such as organic constituents, volatile compounds, isotope content and ratio, and DNA mapping. Combined with chemometrics, fingerprint profiles of agricultural products can be established by analyzing component data related to geographical origin of samples. Current analytical techniques used for determining geographical origin of agricultural products are reviewed in this paper. Furthermore, the future development trends are also discussed.

Surface Layer Protein from Lactobacillus spp. and Its Application: A Review
LIU Yuan-yuan,YANG Xiu-hua,WANG Yuan-liang,LI Zong-jun*
2010, 31(3):  279-283.  doi:10.7506/spkx1002-6300-201003064
Asbtract ( 1183 )   HTML ( 1)   PDF (192KB) ( 676 )  
Related Articles | Metrics

S-layer (surface layer) has been identified as the outermost structure of cellular envelopes in numerous organisms from bacteria and archaea domains. Despite high similarity of amino acid composition in all known S-layer proteins, the typical characteristics of S-layer proteins from Lactobacillus are small molecular weight, high isoelectric point and alkaline protein, which are distinguished from other S-layer proteins. Several species of Lactobacilli contain multiple S-layer protein genes. Intensive attentions have been paid to the applications of surface layer proteins from Lactobacillus, including applications as a functional molecule to covalently absorb fixed matrix, as a carrier of cellular surface display and as a molecular sieve. Therefore, it should have tremendous development perspectives.

A Review of Application of X ray Diffraction in Crystal Structure Determination of Starch Granules
CHEN Fu-quan,ZHANG Ben-shan*,LU Hai-feng,ZHAO Yong-qing,ZHANG Xiang-yang
2010, 31(3):  284-287.  doi:10.7506/spkx1002-6300-201003065
Asbtract ( 1486 )   HTML ( 6)   PDF (271KB) ( 1050 )  
Related Articles | Metrics

Crystallinity of starch granules is important for properties of starch crystals. Current main X ray diffraction methods including Herman method, Wakelin method and Zhang Binshang’s method for the determination of crystal structure are introduced in this paper. The current application status quo, basic principles, advantages and disadvantages of these methods are discussed here. Meanwhile, crystallinity of several common starches such as potato starch, cassava starch, corn starch, rice starch, wheat starch and waxy rice starch determined by these methods is compared. Finally, the prospect development trends for the determination of crystallinity for starch granules are proposed based on the analysis of current problems.

Advance in the Research of Analytical Approaches to Trace Geographical Origin of Animal-derived Foods
SUN Shu-min1,2,GUO Bo-li1,WEI Yi-min1,*,FAN Ming-tao2
2010, 31(3):  288-292.  doi:10.7506/spkx1002-6300-201003066
Asbtract ( 1633 )   HTML ( 0)   PDF (200KB) ( 514 )  
Related Articles | Metrics

Due to the change in diet habits and increasing health awareness, consumers are paying tremendous attentions to the geographical origin of animal-derived food products. As one of the most important parts in food traceability system, geographical origin of food products can be used to not only protect interests of consumers, regional brand and specialty products for ensuring fair competition, but also effectively implement product recall for preventing against the transmission of food-borne pathogens. Analyses of stable isotopes, trace elements and chemical compositions of foods are effective analytical tools to trace geographic origin of food products, which exhibits quite prospects. In this paper, current development status quo and problems in the determination of geographical origin of animal-derived foods, and basic principles of these methods are discussed. The future development directions are also proposed.

A Review of Analysis of Diacetyl-producing Factors during Wine Brewing
QU Hui-ge,XIAO Bo,FENG Zhi-bin,ZHANG Yu-xiang
2010, 31(3):  293-296.  doi:10.7506/spkx1002-6300-201003067
Asbtract ( 1589 )   HTML ( 1)   PDF (361KB) ( 508 )  
Related Articles | Metrics

Diacetyl with appropriate concentration can enhance the complexity of wine flavor. Most diacetyl in wine is produced during malolactic fermentation process. Factors affecting the formation and concentration of diacetyl in wine during wine brewing are reviewed in this paper. Effects of wine components, malolactic bacterial strains, malolactic fermentation parameters and brewing styles are discussed in detail. Therefore, controlling diacetyl concentration at the appropriate level will provide references to improve the flavor of wine.

Research Progress of Chitosanase from Microorganisms
JI Geng-sheng,CHEN Ai-chun
2010, 31(3):  297-301.  doi:10.7506/spkx1002-6300-201003068
Asbtract ( 1129 )   HTML ( 3)   PDF (202KB) ( 791 )  
Related Articles | Metrics

Chitosanase, a glycoside hydrolase, catalyzes the hydrolysis of chitosan to chitosanoligosaccharides. Current research progress of chitosanase at home and abroad including microbial origins, physicochemical properties, molecular characteristics and development status quo are discussed in this paper. The future development trend of chitosanase is also proposed.

Framework of GS1 Full Supply Chain Traceability System for Beef
CAO Wei-zhu,ZHENG Li-min,ZHU Hong*,WU Ping
2010, 31(3):  302-306.  doi:10.7506/spkx1002-6300-201003069
Asbtract ( 1396 )   HTML ( 0)   PDF (267KB) ( 1003 )  
Related Articles | Metrics

GS1 is a new name of EAN/UCC, which is composed of encoding system, automatic identifiable data carriers and electronic data exchange standards. Due to unsolved problems related to the origin tracing of foods, standardization of RFID tags and sharing of dynamic data, it is urgent to establish a full supply chain traceability system for beef. In this study, a general framework of GS1 full supply chain traceability system for beef was established using RFID tags and EAN/UCC codes with EPCglobal tag data standards to conduct tracking from farm to fork. Each information server contained access layer, business layer and resource layer. These servers were heterogeneously distributed to provide user an accessing interface through SOAP or HTTP protocol. In order to accomplish the sharing of dynamic data, information-searching service combined with target-name service was used to locate dynamically distributed information servers.

Current Advances in Preservation Technology of Fresh-cut Fruits and Vegetables
LUO Hai-bo1,JIANG Li1,YU Jian-yong2,ZHOU Xue-ting1,SONG Liu-li1,FU Lin-ran1,YU Zhi-fang1,*
2010, 31(3):  307-311.  doi:10.7506/spkx1002-6300-201003070
Asbtract ( 1433 )   HTML ( 4)   PDF (210KB) ( 896 )  
Related Articles | Metrics

Due to freshness, healthy, hygiene and convenience, fresh-cut fruits and vegetables have been gained extensive attentions in developed countries. However, cleaning, peeling and cutting processes also can result in the quick loss of quality, the acceleration of biological reactions, microorganism contamination and the shorten of shelf-life for fresh-cut fruits and vegetables. This article describes the reasons for the decline of quality of fresh-cut fruits and vegetables, and reviews current advances in preservation technologies such as physical, chemical, biological and combinatorial preservation technologies for fresh-cut fruits and vegetables, which will provide the further understanding of current problems and guidance of future research directions.

Advance in the Research of Techniques for Tannin Removal from Fruits Juice
ZHANG Lei,LU Yuan-ping*
2010, 31(3):  312-315.  doi:10.7506/spkx1002-6300-201003071
Asbtract ( 1392 )   HTML ( 0)   PDF (201KB) ( 1471 )  
Related Articles | Metrics

Tannin, a botanic polyphenolic substance, extensively exists in a variety of vegetables and fruits. In fruits juice processing, a large amount of tannin is easy to enter into fruits juice and results in undesired mouth feeling, color and clarity. So, tannin removal from fruits juice is essential for improving the quality of fruits juice. This article summarizes mechanisms, advantages and disadvantages, and application status quo of current tannin removal techniques, including physical, chemical and biological techniques and others.