Postmortem cooling aging can affect flavor components of meat. In order to explore the effect of cooling aging process on volatile flavor components in yak meat, the Longissimus dorsi muscle from yak in Sunan county was used to determine volatile flavor components by gas chromatography-mass spectrometry (GC-MS). Compared with yak meat without aging treatment, the sulfur compounds (meat flavor) in yak meat with aging treatment exhibited an increase of 24%, especially for 2-acetyl thiazole (meat flavor) and methylthiopropionaldehyde (broth flavor). Both kinds of compounds in yak meat with cooling aging treatment exhibited an increase of 100% and 78%, respectively. Meanwhile, the content of carbonyl compounds exhibited an increase of 311%, including an increase of 331% for 3-hydroxyl-2-butanone (milky aftertaste). The relative content of 3-hydroxyl-2-butanone in yak meat with aging treatment was up to 20.54%. This volatile compound exhibited the highest relative content and the highest level of increase in yak meat with aging treatment. However, phenols, terpenes and sesquiterpenes derived from herbage exhibited a decrease of 34%, which included a reduction of 70% for 4-methyl phenol (pastoral flavor), and a decline of 40% for β-caryophyllene. Therefore, postmortem aging process is beneficial to the improvement of flavor components in yak meat and the reduction of negative impact on the flavor of yak meat due to some special components in herbage.

In this experiment, the post-harvest fruits of kiwifruit cultivar  Hayward  were selected to create a damage model through free-fall movement from a height of 50 cm. An intelligent LCR Hioki tester was used to determine changes in 6 electrical parameters of fruits such as complex impedance (Z), parallel equivalent capacitance (Cp), parallel equivalent inductance (Lp), loss coefficient (D), conductance (G) and impedance phase angle (θ) at electric shock frequencies of 100, 158, 251, 398, 631 kHz and 1000 kHz with the extension of storage time. Results indicated that both damaged and control fruits presented a decrease trend of Z and Lp, an increase trend of Cp and G, an initial increase and then final decrease of D, and an initial decrease and then final increase of θ as electric shock frequency increased at (25 ± 1) ℃. The complex impedance Z at 6 selected electric shock frequencies in damaged fruits was much lower than that in undamaged fruits. Therefore, the parameter can distinguish damaged and healthy fruits as a sensitive electrical parameter. Meanwhile, a significant difference in loss coefficient D between impaired and healthy fruits was determined at electric frequencies of 100 kHz and 251 kHz. As a result, both fruit impedance Z and loss coefficient D can be chosen as an electronic indicator for kiwifruit impairment.

In order to obtain the peanut allergen Ara h1, ammonium sulfate precipitation and size exclusion chromatography were used for the purification. The identification of peanut allergens was carried out using SDS-PAGE and Western blot analysis. The results indicated that peanut allergen Ara h1 was isolated with purity of more than 90%.

In order to explore changes in biochemical properties of muscle proteins from Chinese shrimps (Fenneropenaeus chinensis) during storage at 0 or 4 ℃, basic nutrients, protein composition, salt soluble actomyosin, sulfhydryl content, Ca2+-ATPase activity and hydrophobicity were determined and SDS-PAGE analysis was also conducted at two-day intervals. The results showed that the muscle of Chinese shrimps was a typical food with relatively high protein ((21.75 ± 0.12)%) and low fat ((1.21± 0.03)%). With the extension of storage time, a decrease trend in myofibrillar protein and muscle matrix protein, a pattern of initial increase and final decrease in sarcoplasmic protein and actomyosin, a gradual increase trend in alkali soluble protein and a slow decrease in sulfhydryl content were observed for the muscle of Chinese shrimps. Meanwhile, a significant reduction of Ca2+-ATPase activity was also determined, which exhibited an obvious linear relationship with storage time (R0 ℃= 0.991, R4 ℃ = 0.998). However, the values of the above parameters at 0 ℃ did not significantly differ from those at 4 ℃. Hydrophobicity significantly increased with the extension of storage time, and revealed an obvious linear relationship with storage time (R0 ℃ = 0.976, R4 ℃ = 0.995). SDS-PAGE analysis showed that actin, myosin heavy chain, actomyosin and the protein with a molecule weight of 67 kD were obviously degraded during the storage. Based on a comprehensive consideration of these changes in various indicators, the denaturation of proteins was enhanced due to the extension of storage time. The degree of degradation at 4 ℃ was higher than that at 0 ℃. Ca2+-ATPase activity and hydrophobicity displayed a strong correlation with storage time, which can be considered to indicate the degradation of muscle protein during chilled storage.

On the basis of protein content, amino acid composition and molecular weight distribution of corn oligopeptides (COP), the antioxidant activity of COP in vitro was evaluated by determining the abilities to scavenge DPPH, hydroxyl and superoxide anion free radicals as well as reducing power. Results indicated that the content of total protein was 89.28%, of which acid soluble proteins accounted for 94.31%; amino acid composition was unique and COP was rich in amino acids such as leucine, proline and alanine with strong antioxidant activity. The major molecular weight of COP was less than 1000 (93.05%), and small peptides with a molecular weight range of 132－576 were dominant. The median inhibitory concentrations (IC50 values) of COP for scavenging DPPH, hydroxyl and superoxide anion free radicals on the basis of scavenging rate were 1.9, 5.4 mg/mL and 14.9 mg/mL, respectively. The reducing power of COP at a concentration of 5.0 mg/mL was similar to that of ascorbic acid at 0.02 mg/mL. The antioxidant activity of COP exhibited a dose-dependent relationship.

The antioxidant activities of ethanol extracts from the mycelia and fruit bodies of twenty polypores fungi were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method. Meanwhile, these extracts were tested for their anti-tumor activities by Alamar Blue method. The results showed that the DPPH free radical scavenging and anti-tumor activities of the extracts from fruit bodies of each of these fungi were significantly higher than those of the extracts from mycelia. A DPPH radical scavenging rate of 70% was observed for the ethanol extract of fruit body at a concentration of 5 mg/mL, and the inhibition rates of the ethanol extract against two cancer cell lines such as non-small lung cancer cell NCI-H460 and human hepatoma cell HepG2 were both around 90% at 500 μg/mL. In addition, compared with the normal cell lines, a slightly low inhibition rate of the ethanol extract on drug-resistant cells such as Bel-7402/5-Fu was also observed.

The inhibitory effects of trilobatin separated from Lithocarpus polystachyus Rehd on the activities of α-glucosidase and α-amylase were determined and compared with those of the anti-diabetic drug acarbose as a positive control and the type of the enzymatic inhibition on α-amylase was investigated. Also, rutin was used as a positive control to measure the ability of the trilobatin from Lithocarpus polystachyus Rehd to scavenge DPPH free radicals. The results showed that α-glucosidase activity was inhibited remarkably by the trilobatin, and the inhibition was noncompetitive and did not exhibit a significant difference when compared to acarbose. Its inhibition rate against α-amylase, however, was lower than that of acarbose despite of having stronger DPPH free radical scavenging effect than rutin. From these experimental results, a conclusion could be drawn that the trilobatin from Lithocarpus polystachyus Rehd is a potential anti-diabetic compound.

The bacteriostatic effects of extracts from Russula and Cyclobalanopsis glauca were studied in this paper. Russula roots and Cyclobalanopsis glauca roots and nut were subjected to solvent extraction with 80% ethanol under ultrasonic assistance, and the extracts from both plants were comparatively evaluated for their bacteriostatic effects on Escherichia coli, Micrococcus lueus, Staphylococcus aureus, Aerobacter aerogenns, Karlperth yeast, Penicillium adametzi Zaleski. Results indicated that three extracts had inhibitory effects on Escherichia coli, Micrococcus luteus, and Karlperth yeast. Meanwhile, the inhibitory effects of these extracts on Escherichia coli and Micrococcus luteus were more obvious and exhibited a concentration-dependent manner. Minimum inhibitory concentrations against Karlperth yeast increased in the following order: Cyclobalanopsis glauca root extract ＜ Cyclobalanopsis glauca nut extract ＜ Russula extract. Moreover, the optimal inhibitory concentrations of these extracts were all 2.0 g/mL.

A series of single factor experiments were conducted to evaluate effects of high-pressure intensity (200－600 MPa) and pressure-holding time (10－30 min) on preservative properties of roast chicken during storage at 4 ℃. Results indicated that sterilization effect exhibited an obvious improvement with the increase of high-pressure intensity. A better sterilization effect at a high-pressure intensity of 500 or 600 MPa was observed, which reduced total bacterial and lactic acid bacterial counts by three or four magnitude order. Moreover, the bacterial count in these treated samples remained the lowest level over the whole storage period of 7 days. Sterilization effect was also improved with the extension of pressure-holding time up to 15 min and   tended to be stable in spite of longer pressure-holding time during the whole storage period. The lowest growth rates of total bacteria and lactic acid bacteria were both achieved in treated samples with 20 min of pressure-holding time or longer, which   showed the best preservative properties. Considering comprehensively, the optimal treatment conditions for roast chicken were high-pressure intensity of 500 MPa and pressure-holding time of 20 min.

In order to evaluate the antioxidant activity of persimmon peel extracts (PPE) in vitro, different antioxidant evaluation assays and a mouse model of liver mitochondrial damage induced by Fe2+-H2O2 or Fe2+-VC in vitro were used. The results showed that PPE possessed excellent total antioxidant activity, reducing power, inhibitory activity against lipid peroxidation and radical scavenging activity. The IC50 values against DPPH, superoxide anion and hydroxyl radicals were 57, 137μg/mL and 425 μg/mL, respectively. In addition, PPE could significantly protect mitochondria from lipid peroxidation, swelling, protein oxidation and the reduction of ATPase activity in rats. In conclusion, the current study showed that PPE can resist oxidation obviously in vitro and be utilized as a new natural source of antioxidant.

Gel properties of porcine myofibrillar protein (MP) after heat treatment at varying temperatures (50, 60, 70, 80 ℃and 90 ℃) were investigated. The results showed that gels prepared at 70 or 80 ℃ had a better water holding capacity (WHC) compared with those at other temperatures; gels prepared at 50 or 60 ℃ had a darker color, while those at higher temperatures had similar color (P＞0.05). The hardness and chewiness rose at the beginning of heating and then decreased with increasing temperature; the best functional properties were obtained at a temperature ranging from 70 to 80 ℃. Turbidity first went up with increasing temperature and then changed little when the temperature was above 70 ℃. SDS-PAGE studies indicated that visible 45－65 kD bands appeared when the temperature reached 70 ℃ or higher, suggesting the occurrence of partial protein degradation. Thus, MP gels formed at a temperature between 70 ℃and 80 ℃ have better functional properties.

The oxidative effect of 4 h exposure to H2O2 at different concentrations on HepG2 cells was measured by determining DNA damage by single cell gel electrophoresis technique and assaying MDA content and the activities of SOD and GSH-Px in HepG2 cells. An experimental model of oxidative stress was established based on the optimal concentration of H2O2. The results showed that the optimal H2O2 concentration determined was 100μmol/L and construction of the HepG2 cell model of oxidative injury came to success after 4 h treatment with H2O2 at this concentration.

Whey protein isolate (WPI) is one of commonly used film-forming materials and has been considered as a good barrier to oxygen but a poor one to water vapor. In the present study, film-forming properties of Maillard reaction products (MRPs) formed from WPI and xylose such as physical and mechanical properties and water vapor permeability were investigated at different amounts of xylose and glycerol with the aim of optimizing film-forming conditions and a comparison with those of WPI was carried out. In addition, the effects of coating with WPI or WPI/xylose MRPs on lipid peroxidation in walnut kernel were probed. The results indicated that the optimal film-forming conditions of WPI/xylose MRPs were determined to be heating a reaction system containing 10 g of WPI, 5 g of xylose and 5 mL of glycerol per 100 mL at 80 ℃ for 45 min or at 90 ℃ for 30 min. Compared with WPI film, WPI/xylose MRPs film revealed a two-fold increase in penetration strength, an around 2.5-fold elongation strength and a decrease in water vapor permeability by about 24%. Coating with WPI/xylose MRPs film could delay the increase in acid value of walnut kernel, whereas coating with WPI film had no obvious inhibitory effect.

Analysis of the effect of microwave treatment at different levels of power on the secondary structure of wheat gluten protein (WGP) was carried out using FTIR. The results showed that the secondary structure of WGP varied with different levels of microwave power. To indirectly figure out the effect of microwave on the spatial structure of WGP, changes in the hydroxyl stretching intensity, surface hydrophobicity, and free sulfhydryl group and disulphide bond contents of WGP were measured before and after microwave treatment. A decrease in hydroxyl stretching intensity, an increase in surface hydrophobicity, the breaking of disulphide bond and its conversion into sulfhydryl group were observed for WGP after microwave treatment. From these results, it could be concluded that microwave has an impact on the secondary bonds deciding the spatial structure of WGP. Furthermore, the particle distribution and apparent viscosity of microwave treated WGP were determined, and the results of decreases in volume particle size and in apparent viscosity demonstrated that the compact structure of WGPwere disrupted and became incompact.

Changes in physical and chemical indexes of frying oil and their correlations were analyzed during potato chips frying in this study. The results showed that the refractive index, color, acid value, carbonyl value and total polar material of frying oil increased with prolonged frying time, peroxide value first increased and then decreased, iodine value displayed a decrease, and changes in specific gravity, viscosity and saponification value were irregular. There were very significant positive correlations among acid value, carbonyl value, total polar material, color and refractive index, and all the correlation coefficients were greater than 0.9. Moreover, total polar material of frying oil could be predicted by acid value and color.

Comparisons on quality characteristics and textural properties of salty doughnut samples based on glutinous rice, japonica rice or indica rice were conducted. Based on this, physico-chemical characteristics of different cultivars of indica rice and sensory and texture properties of processed salty doughnut were determined and meanwhile, an investigation to analyze correlations between indica rice characteristics and sensory and texture properties of processed salty doughnut was studied in order to provide evidence for selection of rice material for salty doughnut. The results showed that chalkiness degree and the contents of protein and amylose were major characteristic indicators of rice cultivars. The content of amylase had significantly positive correlation with the quality of salty doughnut. Thus, it can be used an indicator for selection of rice material for salty doughnut.

Schisandrin B obtained from the fruits of Schisandra chinensis by supercritical carbon dioxide extraction and subsequent preparative HPLC separation was tested for its free radical-scavenging and antimicrobial activities in vitro. The results showed that Schisandra chinensis-derived schisandrin B had higher hydroxyl radical scavenging effect (IC50 = 0.2 mg/mL) but lower superoxide anion radical scavenging effect (IC50 = 0.24 mg/mL) when compared with vitamin C at the same concentrations. The compound could inhibit Staphylococcus aureus, Candida albicans, Salmonella, E.coli and Bacillus subtilis, especially against Candida albicans and Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 0.25 mg/mL. However, no obvious inhibitory effect on Rhizopus, Aspergillus niger or Nanyang yeast was observed.

DPPH radical scavenging assay was used to evaluate the antioxidant activities of ethanol extracts from twenty edible spices, and the results showed that most of them had antioxidant effect and Zanthoxylum bungeanum was the strongest antioxidant among them, followed by clove, cinnamon, bay leaf and lesser galangal. Meanwhile, the contents of total flavonoids and total phenols in twenty spices were determined by aluminium chloride and Folin-Ciocalteu colorimetric assays, respectively, and their correlations with DPPH radical scavenging effect were analyzed. It was found that DPPH radical scavenging effect was correlated with the contents of total flavonoids or total phenols, especially with the content of total flavonoids (R2 = 0.8111). Furthermore, Zanthoxylum bungeanum was found to contain the highest amount of total flavonoids among twenty spices. Hence, the spice is expected to be exploited as a new source of antioxidant.

In this study, DPPH radical scavenging activities and reducing powers of flavonoids from 9 different varieties of citrus peel were compared. Meanwhile, the effect of macroporous resin purification on these antioxidant activities was studied. The results indicated that both DPPH radical scavenging activities and reducing powers of flavonoids differed significantly among 9 varieties of citrus peel (P < 0.05). Both crude and purified flavonoids from Nanfeng citrus peel revealed the strongest DPPH radical scavenging activity and reducing power, with median inhibitory concentrations (IC50)  of (0.38 ± 0.03) mg/mL and (0.086 ± 0.003) mg/mL for scavenging DPPH radicals, respectively and reducing powers of  for flavonoids from Nanfengju before and after purification were (0.166 ± 0.002) mg/mL and (45.69 ± 1.38)μg/mL, respectively. On the other hand, flavonoids from Fujian sweet mandarin peel revealed the weakest DPPH radical scavenging activity and reducing power. The IC50 values for DPPH radical scavenging activity of flavonids from Fujian sweet mandarin peel before and after purification were (0.88 ± 0.02) mg/mL and (0.281 ± 0.003) mg/mL, and those for reducing ferric ion before and after purification were (0.306±0.003) mg/mL and (97.80 ± 1.06)μg/mL, respectively. Therefore, macroporous resin purification could result in a significant enhancement in antioxidant activities of flavonoids from citrus peel. The DPPH radical scavenging activities of flavonoids from Xinhui mandarin peel and Jiangxi navel orange peel revealed 8.3- and 2.6-fold enhancement after purification, and the reducing powers of flavonoids from Jiangxi navel orange peel and Jiangxi Liucheng orange peel exhibited 4.5- and 2.8-fold increase after purification, respectively.

In this study, rheological properties of κ-carrageenan gum, konjac gum and their mixed gel (5.5:4.5, m/m) in aqueous solution all at a concentration of 1 g/100mL were measured and compared. This was followed by an investigation to explore effects of temperature and electrolytes on rheological properties of these three solutions. Results indicated that the storage modulus (G＇) of the compound gel was obviously higher than that of κ-carrageenan gum and konjac gum; while, the loss modulus (G") was lower than that of κ-carrageenan at 30 ℃. In addition, the compound gel revealed obviously enhanced gelling properties. With the increase of temperature, the storage modulus (G＇) was always bigger than the loss modulus (G") in the compound gel so that the compound gel had typical viscoelatic fluid properties. Moreover, respective additions of KCl and CaCl2 at a concentration of 0.1 g/100mL could result in the decrease in storage modulus (G＇) and the increase in translation temperature of the compound gel.

Corn germ was harvested during germination in a light or dark environment at different levels of temperature, and immersed in 0.05 mol/L phosphate buffer at pH 7.8 for different periods of time before SOD extraction and subsequent SOD activity measurement in order to explore the effects of germination and extraction conditions on SOD activity in corn germ. A maximum SOD specific activity of 4487.28 U/mg was obtained after the following operations: corn germination for 4 d under light illumination at 30 ℃, immersing of resulting corn germ in 200 mL of 0.05 mol/L phosphate buffer at pH 7.8 for 36 h, milling on a colloid miller, extraction for 1 h, thermal precipitation at 60 ℃ for 15 min, SOD precipitation from the supernatant by adding a 1.5-fold volume of －20 ℃ acetone, and sequential separation on cellulose-DE-52 and SephadexG-75 chromatographic columns, which exhibited a 3.86-fold increase in comparison with ungerminated corn germ (924.18 U/mg).

Chinese wolfberry fruits were fermented separately by two types of yeasts to produce fruit wines. Changes in flavonoid content, pH and alcohol content were measured during the fermentation period. Results indicated that both the contents of flavonoid and alcohol revealed a gradual increase and then remained at a stable level during the fermentation process. A quadratic regression model for flavonoid content as a function of alcohol content was developed, revealing a good correlation between both parameters based on regression analysis. pH decreased slightly at first and then was kept at a stable level during the fermentation period. Neither flavonoid content nor pH presented significant change. However, different change rates of the three parameters were observed.

The contents of total polyphenols total antioxidant activity, reducing power and hydroxyl radical scavenging capacity of 70% methanol extracts from raw, processed and preserved Carya cathayensis Sarg kernel were determined by Folin-Ciocalteu colorimetry and their total antioxidant activity, reducing power and hydroxyl radical scavenging capacity were measured. Total polyphenols contents were 1065.4, 319.78 mg/L and 204.4 mg/L in the extracts from raw, processed and preserved Carya cathayensis Sarg kernel, respectively. The total antioxidant activity and reducing power of the three extracts as evaluated with 2140 mg/L vitamin E as a reference standard decreased sequentially in the following order: raw Carya cathayensis Sarg kernel ＞ vitamin E ＞ processed Carya cathayensis Sarg kernel ＞ preserved Carya cathayensis Sarg kernel. In the case of hydroxyl radical scavenging rate, the order was vitamin E ＞ raw Carya cathayensis Sarg kernel ＞ processed Carya cathayensis Sarg kernel ＞ preserved Carya cathayensis Sarg kernel. Furthermore, total antioxidant activity, reducing power and hydroxyl radical scavenging rate had close correlation with the content of total polyphenols. Therefore, polyphenols are the important antioxidant components in Carya cathayensis Sarg kernel.

In order to explore the mechanism by which propolis controls postprandial blood glucose, the inhibitory effect of ethanol extract from propolis (EEP) on α-glucosidase was evaluated by using α-glucosidase inhibition model in this paper. Inhibitory kinetic parameters were determined by Lineweaver-Burk plot. The results indicated that the median inhibitory concentration (IC50) of EEP was (0.8260 ± 0.1754) mg/mL and the inhibition constant (KI) was (0.0265 ± 0.0060) mg/mL. Kinetic analysis showed that the inhibitory mechanism of EEP on α-glucosidase was a typical noncompetitive inhibition. Therefore, propolis seems to be a healthy food choice for the adjustment of blood glucose.

In this work, changes in nitrogen existing form, taste, free amino acid composition and the contents of delicious and bitter amino acids in chicken bone protein were investigated during enzymatic hydrolysis with Flavourzyme. The results indicated that both amino nitrogen and soluble nitrogen gradually increased with the extension of Flavourzyme-catalyzed hydrolysis, while peptide nitrogen first increased up to its maximum and then decreased. As the hydrolysis time was prolonged, the umami taste of chicken bone protein hydrolysate presented an increase, and the bitter taste gradually tended to be stale during later stages of the hydrolysis. The content of free amino acids reached its maximum level after 24 hours. Therefore, a large number of released tasty amino acids seem to be responsible for the flavor of chicken bone protein hydrolysate. Tricine-SDS-PAGE analysis showed that polypeptides were gradually degraded during the hydrolysis of chicken bone protein and that all peptide molecules in the 24 h hydrolysate had a molecular weight of less than 10.0 kD.

Brown pigment extracted from hickory shell with 95% alcohol and purified on AB-8 macroporous resin column was subjected to evaluation of antioxidant and antimicrobial activities and infrared spectroscopic analysis. The results showed that the total antioxidant capacity of the brown pigment at a concentration of 3.0 g/L was equivalent to 126.65 mmol/L α-tocopherol. The EC50 value (the effective concentration at which the absorbance was 0.5) of reducing power for the pigment was 0.286 g/L. The scavenging rate against hydroxyl free radicals reached 60.84 % at 1.0 g/L. The MIC (minimum inhibitory concentration) values of antibacterial effects on Saccharomyces cerevisiae, Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Aspergillus niger were 0.125, 0.25, 0.25, 1.0 g/L and 0.5 g/L, respectively. IR spectral analysis revealed the presence of benzene ring and phenolic hydroxyl in the pigment.

In this study, 70% ethanol extract from the bulbs of Allium macrostemon Bunge was tested for its antibacterial activities against five common microbes. Meanwhile, the stability of its inhibitory effects on E. coli, Aspergillus niger and Saccharomyces cerevisiae was explored. The results showed that the extract sequentially inhibited five common microbes in the following order: E. coli ＞ S. aureus ＞ Penicillium ＞ Saccharomyces cerevisiae ＞ Aspergillus niger. Stability experiments revealed that temperature and pH had strong influence on the antibacterial effect of the extract. The extract exhibited the strongest inhibitory activity at a temperature ranging between 50 ℃ and 60 ℃, which became lower when the temperature was higher than 100 ℃. In addition, the antibacterial activity of the extract was strong under neutral, slightly acidic and slightly alkaline conditions, and decreased with decreasing acidic pH or increasing alkaline pH, and was little affected by UV light illumination and K+, but was affected obviously by some divalent cations such as Mg2+, Ca2+ and Zn2+ as well as Fe3+ as a tervalent cation which had larger effect than these divalent cations.

In order to explore the spoilage characteristics of dominant spoilage bacteria, Pseudomonas spp., Brochothrix thermosphacta and Enterbacteriaceae were inoculated into sterilized pork at different storage temperatures of 4, 0 ℃ and－5 ℃. Sensory evaluation score, aerobic bacteria count, total volatile basic nitrogen (TVB-N) value and thio-barbituric acid (TBA) value were determined on each storage day. Bacterial poilage capability was evaluated based on TVB-N production factor Y(TVB-N/CFU), which was calculated from TVB-N value divided by colony forming unit (CFU). The results indicated that strong spoilage odor occurred on the 5th storage day. The counts of B. thermosphacta in thawed pork were 11.28 lg(CFU/g), 9.36 lg(CFU/g) and 6.62 lg(CFU/g) at storage temperatures of 4, 0 ℃ and －5 ℃, respectively; while TVB-N values were 14.92, 14.50 mg/100g and 9.10 mg/100g, according to relative storage conditions. Similarly, the counts of Pseudomonas spp. were 9.46 lg(CFU/g), 8.87 lg(CFU/g) and 5.37 lg(CFU/g) under the storage temperature of 4, 0 ℃ and －5 ℃, respectively; while TVB-N values were 21.59, 14.49 mg/100g and 8.97 mg/100 g, respectively. This study showed that B. thermosphacta and Pseudomonas spp. were dominant in thawed pork, with significantly stronger spoilage capability than others dominant bacteria.

Changes in the microbial community and quality of black-gill bighead croaker meatballs with added chitosan at levels of 0, 0.05%, 0.15%, 0.25%, 0.35% and 0.5% as an excellent biological food preservative were investigated during storage at 0 ℃ in a vacuum packaging environment. It wad found that adding chitosan at 0.5% could markedly extend the shelf life of black-gill bighead croaker meatballs, and inhibit microbial growth, revealing a significant (P ＜ 0.05) inhibitory effect against the dominant microbes including Enterobacteriaceae, Pseudomonads, Micrococcaceae and Staphylococcus. No obvious antimicrobial effect was observed when chitosan was added at a level of less than 0.5%; meanwhile, both the pH and total volatile basic nitrogen of black-gill bighead croaker meatballs showed a notable decrease, the harness was remarkably elevated, and little change in the springiness was observed. 

The aim of this work was to study the effect of milk protein fortification on the sensory quality, viscosity and water holding capacity (WHC) of stirred yogurt, where reconstituted milk was fortified with skim milk powder (SMP) or whey protein concentrate (WPC-80) to different protein contents of 2.7%, 3.1%, 3.5% and 3.9%, respectively. The results showed that the quality, viscosity and WHC of stirred yogurt were significantly improved after protein fortification with SMP or WPC-80. Stirred yogurts fortified with different levels of SMP showed an obvious difference in texture, a slight difference in flavor, and no difference in color. Identical results were found for fortification with different levels of WPC-80. In addition, the viscosity and WHC of yogurt were both dramatically elevated as the fortification level increased. Protein fortification with SMP at 2.7% provided the best sensory quality of yogurt, and the amount of WPC-80 addition for the best sensory quality of yogurt was 3.5%. WPC-80 was more beneficial to the sensory quality and WHC of yogurt than SMP at the same fortification levels, while SMP fortification provided higher viscosity. Based on a comparison between perceived and instrumentally measured viscosity values, stirred yoghurt with higher viscosity did not necessarily have better quality, and the best viscosity was between 537 mPa·s and 712 mPa·s. It can be concluded from this study that the best protein fortification protocol for stirred yoghurt is adding WPC-80 at 3.5%.

Changes in the content, and composition and antioxidant activity of phenolic compounds during oat germination were analyzed. The results showed that total phenol content in oat went up notably with the extension of germination, and oat buds and roots had higher total phenol content than oat grains, which resulted in a difference in antioxidant activity. Ungerminated oat seeds, 6-day germinated oat grains, 6-day germinated oat buds and 6-day germinated oat roots had strong reducing power, with EC50 (median effective concentration) of 86.47, 61.96, 98.54μg/mL and 51.98μg/mL, respectively, and strong abilities to scavenge DPPH free radicals, with IC50 (median inhibitory concentration) of 26.90, 15.43, 30.71μg/mL and 21.30μg/mL and nitrite, with IC50 of 0.653, 0.441, 1.353 mg/mL and 0.227 mg/mL. Therefore, germination is an effective method to elevate the utilization value of oat.

The isolation, purification and physi-cochemical characterization of mycelial polysaccharides from Phellinus baumii were studied. Two polysaccharide fractions were separated from crude deproteinized polysaccharides from Phellinus baumii mycelia by DEAE-52 cellulose column chromatography, followed by purification on Sephadex G-100 gel filtration column. The two fractions were determined by HPLC to contain neither protein nor nuclear acid and to be pure non-starch polysaccharides, their molecular weights were 4.74×104 D and 8.71×103 D, respectively, and they were both composed of rhamnose, arabinose, xylose, galactose and glucose in a molar ratio of 3.47:1.99:1:63.27:13.44 and 10.46:1:1.03:182.75:30.94, respectively.

Potato starch was formed into sodium carboxymethyl starch (CMS) by solvent method, and the rheological properties of potato CMS in aqueous solutions were studied. Based on the fact that potato CMC can be dissolved and gelatinized at a low temperature, potato CMS aqueous solutions at concentrations of 0.5, 1.0, 2.0 g/100 mL and 4.0 g/100 mL were tested using a NDJ-9S rotation viscometer in a low-temperature range (20, 30, 40, 50 ℃ and 60 ℃) for their apparent viscosities at different shear rates, and a rheological model for potato CMS solutions was constructed, followed by deduction of rheological properties. In addition, the effects of adding sodium chloride at a concentration of 1.5 g/100 mL, citric acid at 0.2 g/100 mL or sugar at 5 g/100 mL on the rheological properties of 4 g/100 mL potato CMS solution were explored. Potato CMS solution was found to be a pseudo-plastic fluid, of which the apparent viscosity was markedly affected by temperature, concentration, shear rate, and so on. Adding sucrose had little effect on the rheological properties of potato CMS solution, while potato CMS solution displayed an obvious decline in its apparent viscosity and shear stress after addition of sodium chloride or citric acid.

Soybean is a versatile food and a rich source of essential nutrients but contains many antinutritional factors. The effective elimination of antinutritional factors has key significance for better absorption of nutrients from soybean. In this study, soybean was homogenated in various modes of heat treatment, and obtained homogenates were measured for their contents of several antinutritional factors such as phytic acid, saponin and trypsin inhibitors and nutrients including protein, total amino acids, free amino acids, fatty acids and minerals. The results indicated that various modes of heat treatment had some effect on the major nutrients in soybean homogenate. Compared with other heat treatment modes investigated in this study, 10 min homogenization at 125 ℃ and 0.135 MPa resulted in slightly higher contents of total protein and total amino acids, an increase in some free amino acids but a decrease in others. Meanwhile, the heat treatment mode could eliminate phytic acid, saponin and trypsin inhibitors and the eliminating effect on saponin and trypsin inhibitors was especially obvious. Therefore, it is an ideal heating method for soybean product processing.

Acrylamide inhibition through reducing the acrylamide precursors including asparagine and reducing sugars, by the use of asparaginase and/or substituting some of the added sugar using stevioside were investigated for their effects on dynamic rheology, hardness of dough, and for baking and sensory properties of the prepared cookies. Using 1000 Asparaginase Unit (ASNU) reduced the asparagine contents 67% of the asparagine content of control sample (0.045 mg/g), and that could inhibit 95% of the formed acrylamide in the control sample without affecting the cookie quality attributes. Together with substituting sugars achieved more than 96% inhibition of acrylamide formed in the control sample (160.6). Dynamic rheological results showed that asparaginase did not have effects on G＇, G〃or tanδ, while sugar substitution increased G＇ and G〃 because of the development of gluten network in the cookie dough with the sugar substitution because of the absence of 15%, 30%, 45% and 60% of sugar. Substituting sugars altered some of the cookie quality attributes such as, increased moisture contents, less color development, less spread ratio, less breaking forces which was reflected to the lower acceptance for the panelists which did not accept the 45% and 60%, but substituting 15% or 30% sugar was accepted for the panelists.

Yersinia enterocolitica has been paid so much attention as a kind of foodborne pathogen. The pre-enrichment of Yersinia enterocolitica was conducted by using the cultivation in TSB, PSB and ITC media. The pre-enrichment effect was evaluated by real-time PCR. The results indicated that the cultivation in TSB medium was better than other two media for pure Yersinia enterocolitica system. The enrichment time was 24 h. In addition, an enhanced sensitivity and shorten enrichment time (8 h) of Yersinia enterocolitica were achieved in the mixed microbe system containing TSB and ITC. Therefore, PSB can be used in the detection of Yersinia Enterocolitica in samples.

Pleurotus cituinopileatus is an important kind of edible medicinal fungi. Totally 18 kinds of Pleurotus cituinopileatus strains were collected from some markets in China. Inter-simple sequence repeat (ISSR) method was used to analyze genetic polymorphism of Pleurotus cituinopileatus strains. A total of 102 DNA fragments were amplified by using eleven ISSR primers, and 78 of these fragments were polymorphic with polymorphism rate of 76.4%. Meanwhile, high-level genetic polymorphism was observed in Pleurotus cituinopileatus and the genetic similarity coefficients (GSC) were between  0.50 and 0.96. These 18 strains were divided into 2 groups at GSC of 0.62 and 7 groups at GSC of 0.75 according to the cluster analysis of UPGMA method. Strain 16 had an independent genetic system. These results will provide a scientific fundament to accelerate genetic breeding and identification of cultivated strains of Pleurotus cituinopileatus.

Chitooligosaccharides exhibit a broad range of potential applications in the fields of biomedicine, pharmaceuticals, food, cosmetics and agriculture. In the present study, based on the results from single factor tests, response surface methodology (RSM) combined with central composite design was used to optimize cultivation conditions of Bacillus thuringiensis ZJOU-010 for producing chitosanase. The optimal conditions were achieved to be shrimp shell powder (SSP) concentration of 44.96 g/L, (NH4)2SO4 concentration of 1.48 g/L, and pH of 6.78. Under the optimal conditions, the chitosanase activity from Bacillus thuringiensis ZJOU-010 was 4.25 U/mL. The obtained value of chitosanase activity was in good agreement with the predicted value (4.16 U/mL). Meanwhile, 18.47% improvement on chitosanase activity after the optimal cultivation was achieved, when compared with the chitosanase activity of 3.59 U/mL before optimization. These results indicated that oligosaccharides could be produced using shrimp processing by-products as the carbon and nitrogen sources.

A bacterial strain designated as XJU-8 was isolated from alkaline sewage samples from Shihezi city, Xinjiang. This bacterial strain was a gram-positive, spore-forming, aerobic bacillus. It could grow in LB medium with a broad range of pH (5.0－13.0). The optimal growth conditions for this bacterial strain were 37 ℃ and pH 10.5. Its tolerance to NaCl was up to 15%. The 16S rRNA gene sequence analysis showed that the strain XJU-8 was highly related to B. claussi with 99% similarity. The G+C content in its genomic DNA was 43.67%. The strain XJU-8 was confirmed as B. claussi by comparing its physiological, biochemical and genetic characteristics with those of B. claussi GMBAE 42. Due to its excellent pH tolerance and several phenotypic characteristics, this strain was further confirmed and classified as a new member of B. claussi species. This strain also could produce an extracellular alkaline pectinase with the maximum enzyme activity at 50 ℃ and pH 10.0. More than 80% activity of this alkaline pectinase was remained at pH value ranging from 9.0 to 12.0. The activity of the alkaline pectinase could be enhanced in the presence of Ca2+. These properties demonstrated that this enzyme might be suitable for paper-making, coffee and tea fermentation, textile industries and other industrial applications.

Destarched bracken roots were solid-state fermented with Ganoderma lucidum and the fermentation residue was harvested and submitted to enzymatic hydrolysis and subsequent absolute ethanol precipitation to obtain soluble dietary fiber (SDF). The amounts of destarch bracken roots and water in fermentation medium and culture temperature were identified as main factors that influence SDF yield, and optimized by response surface methodology combined with central composite design. The results showed that the optimum amounts of destarch bracken roots and water in fermentation medium and culture temperature were 84%, 63% and 27 ℃, respectively. Under these conditions, the predicted and experimental values of SDF yield were 13.034% and 12.885%, respectively. The fact that they were not significantly different demonstrated that the developed regression model could experimental data well and was qualified. Moreover, the experimental value of SDF yield (12.885%) was significantly higher than the value of 1.733% obtained without Ganoderma lucidum fermentation before enzymatic hydrolysis.

The optimal process for the hydrolysis of cotton stalks with dilute acid was investigated by orthogonal array design on the basis of the highest cellulose content and the lowest lignin content. The optimal acid hydrolysis conditions for cotton stalks was dilute acid concentration of 1.0%, solid-to-liquid ratio of 1:15, hydrolysis temperature of 100 ℃ and hydrolysis time of 2.0 h. Plackett-Burman design was used to screen 4 major factors including material-loading amount in a 250 mL fermentation vessel, bran content, co-fermentation time and Penicillium inoculation amount from 9 factors such as yeast inoculation amount, yeast inoculation time, Penicillium inoculation amount, co-fermentation time, initial pH, water content, temperature, bran content and material-loading amount, and their optimum levels were determined by response surface methodology to be 1/3, 4%, 53 h and 10%, respectively. An average content of single cell protein of 25.38% was obtained in validation experiments developed under the optimal parameters, between which and the theoretical value of 22.79%, there was 2.59% difference. Therefore, this established model is feasible.

The bacteriocin produced by Lactobacillus plantarum KLDS1.0391 was separated using ultrafiltration membranes with molecular weight cut off (MWCO) of 1 kD and 3 kD. The effects of major parameters on membrane flux and antibacterial activity of bacteriocin were studied. The antibacterial activity of bacteriocin was analyzed and compared after ultrafiltration. Results indicated that the optimal ultrafilitration conditions were ultrafiltration pressure of 0.140 MPa, ultrafiltration temperature of 30 ℃ and ultrafiltration time of 120 min. MWCO of 3 kD was selected for separating bacteriocin produced by Lactobacillus plantarum KLDS1.0391. The antibacterial activity of bacteriocin was increased from 574.99 to 1849.40 IU/mL. The specific activity was 185.96 IU/mg, which revealed 8.0 folds and 3.0 folds enhancement in purification and condensation.

Due to the lack of effective monitoring parameters for anaerobic lactic acid fermentation process, it is difficult to observe the change in physiological status of lactic acid bacteria during the fermentation process. Oxidoreduction potential (ORP) can reflect the status change of anaerobic lactic acid fermentation system. In this study, the optimal addition concentration and time of corn syrup were explored through the evaluation of ORP change. Results indicated that the optimal addition concentration and time of corn syrup were 0.5% and 30 h, respectively. The addition of corn syrup could effectively regulate carbon-nitrogen ratio during the late stage of fermentation and maintain a beneficial reducing environment for lactic acid synthesis, which resulted in a 20% enhancement of lactic acid production. Therefore, ORP can be a monitoring parameter of lactic acid fermentation process, and corn syrup can modulate the ORP during fermentation process.

Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method was used to determine the polymorphism of exon 4 of CAPN1 gene in 147 Shouguang chicken, and analyze the correlation between CAPN1 gene and meat quality traits in Shouguang chicken. Three genotypes were identified as AA, AB and BB with the genotype frequencies of 0.286, 0.510 and 0.204, respectively. Statistical analysis indicated that type BB Shouguang chicken had significantly higher breast muscle pHu value than type AA (P＜0.05). However, type AA Shouguang chicken had significantly higher content of intramuscular fat than type BB (P＜0.05).

A surfactant-stable alkaline protease was isolated and purified from Bacillus licheniformis XG12, and its enzymatic properties were also characterized. A protease with high purity from strain XG12 was purified by precipitation with ammonium sulfate, DEAE-Sepharose ion exchange chromatography and Sephadex G-75 gel filtration chromatography. The purified protease exhibited a 42.6-fold enhancement in specific activity and its recovery rate was 25.3%. The enzyme was composed of a single polypeptide chain with an apparent molecular mass of 29.5 kD as determined by SDS-PAGE. This alkaline protease was highly active and stable in the pH range of 7.0－11.0 with an optimal pH of 10.0. The maximum activity of this alkaline protease was observed at 40 ℃. In addition, this protease could be activated by divalent cations such as Mg2+, Ca2+ and Mn2+ and inhibited by serine-protease inhibitors, suggesting that this alkaline protease was a serine-protease. Moreover, this alkaline protease also exhibited extreme stability towards anionic (0.1% SDS), cationic (0.1% CTAB), non-ionic surfactants (1% Tween-80, 1% Tween-20 and 1% Triton X-100) and oxidants. Due to its promising properties, this alkaline protease from Bacillus licheniformis XG12 will have potential applications in food and laundry detergents.

In order to increase the storage time and ensure edible safety of crab paste and salted mudsnail, bacterial analysis of crab paste and salted mudsnail was conducted. Three bacterial strains were isolated from salted mudsnail and identified as Bacillus flexus, Aerococcus viridans and Brevibacterium casei. Similarly, 4 bacterial strains were isolated from crab paste and identified as Staphylococcus gallinarum, Moraxella catarrhalis, Micrococcus luteus and Photobacterium angustum. In addition, highly consistent results were observed between 16S rRNA analysis and MIS identification among these strains expect for Photobacterium angustum. Most bacterial strains exhibited faster growth with the increase of temperature. Six bacterial strains had significantly tardy growth under the condition of low-temperature refrigeration (4 ℃), indicating that low-temperature storage could inhibit bacterial growth and is suitable for the extension of shelf-life time. Seven bacterial strains had protease activity, Micrococcus luteus and Photobacterium angustum could not decompose starch, and all bacterial strains could not decompose ester. These bacterial strains could grow in the temperature range of 4－35 ℃ with the optimal temperature of 35 ℃, in the pH range of 5.0－9.0 with the optimal pH of 7.0, in the NaCl concentration range of 3%－7% with the optimal concentration of 3%.

In this study, the genomic DNA of Asparagus officinalis L. was extracted by plant genome extraction method, and its fragment of 18S rDNA was amplified by PCR method, followed by ligation, transformation, and screening. An 18S rDNA fragment of 1684 bp in length was sequenced. The accession number of the sequence in Genbank was GU217543. The gene sequence of Asparagus officinalis L. was analyzed. The results indicated that Asparagus officinalis L. had close genetic relationship with the species of Liliales and Asparagales. Based on these investigations, the classification of Asparagus officinalis L. has been further understood at the molecular level.

In this study, the effects of some rare earth elements such as La3+, Ce3+, Nd3+, Pr3+ and Er3+ on the production of polysaccharides and triterpenoids by liquid fermentation of Ganoderma lucidum were explored. The results indicated that obvious stimulation effects of these rare earth elements on the production of polysaccharides and tritepenoids were observed. Moreover, Pr3+ at concentrations of 0.01, 0.001 mmol/L and 0.1 mmol/L revealed the most obvious improvement on the production of intracellular polysaccharides (IPS), extracellular polysaccharides (EPS) and intracellular triterpenoids (IGT) with yields of 772.56, 452.76 mg/L and 398.49 mg/L, respectively. Compared with the control group, three components were increased by 4.67, 3.05 folds, and 1.91 folds due to Pr3+ treatment. However, La3+ at a concentration of 0.001 mmol/L showed a remarkable enhancing effect on EPS and the yield of EPS was up to 610.08 mg/L with a 2.03-fold enhancement. Therefore, the rare earth elements at appropriate concentrations can obviously increase the production of polysaccharides and triterpenoids in Ganoderma lucidum during liquid fermentation.

A strain with higher acid phytase activity isolated from soil was identified as Aspergillus niger. The optimal fermentation conditions for improved production of phytase by the strain were incubation in a medium composed of 3 g/100mL wheat bran and 0.5 g/100mL (NH4)2SO4, at an initial pH of 5.5 for 84 h. Under the optimal fermentation conditions, the phytase activity was up to 12.06 U/mL. The optimal reaction pH and temperature of this enzyme were 5 and 45 ℃, respectively. The relative enzyme activity remained to be 60% after heating treatment at 55 ℃ for 30 min. In addition, the enzyme was stable in acidic and neutral media. The phytase activity was inhibited by Ca2+, Fe2+, Na+, K+, Zn2+ and Cu2+, while activated by Mg2+ and Ba2+.

In this study, an alkaliphilic strain (HSL38) producing xylanase was isolated from mangrove soil, and identified as Bacillus halodurans C-125 (GenBank: NC_002570.2) based on 16S rDNA analysis, which revealed a similarity of 99%. Specific primers based on theβ-1,4-xylanase gene xynA of Bacillus halodurans C-125 were designed, and theβ-1,4-xylanase gene (xyl-BH-G10) from HSL38 strain was amplified. Sequence analysis showed 99% similarity between the xynA gene and the amplified gene encoding a precursor of 396 amino acid residues (45.27 kD), which belonged to glycoside hydrolase family 10 GH10. A recombinant expression plasmid was constructed by linking xyl-BH-G10 to the expression plasmid pET-30a-c(+), and then transformed into E. coli BL21(DE3). The expression of recombinant protein was achieved under IPTG induction. These investigations indicated that theβ-1,4-xylanase gene xyl-BH-G10 was highly expressed in E. coli BL21 (DE3) cells under the optimal induction conditions, and an xylanase activity of 55.28 U/mL was obtained, which exhibited a 4-fold enhancement when compared to the fermentation of original HSL38 strain.  

The aim of the present study was to optimize the continuous ultrasonic extraction process for isoflavone aglycones including genistein, daidzein and glycitein produced by Streptomyces roseolus (ATCC 31047) based on Plackett-Burman design and orthogonal array design. Results indicated that the order of three positive factors affecting extraction efficiency from strong to weak was solvent composition (ethanol aqueous solution), ultrasonic treatment time and eluent volume. However, extraction temperature and eluent flow rate exhibited a negative impact on extraction efficiency. Ultrasonic treatment time of 7 min and solvent composition of 70% ethanol concentration were found optimal, and the extraction rate of total isoflavone aglycones reached up to (98.7 ± 1.23)% under the optimal conditions. The application of solid-phase extraction (SPE) could effectively reduce the interference of impurity substances during the quantitative analysis of the above three isoflavone aglycones so that the detection limit of the developed SPE-HPLC method could reach 10-3μg/mL. The detection procedure was less than 10 min and the recovery rate was between 96.2% and 103.4% with a RSD of less than 2.34%. Therefore, this method can meet the requirements for high-efficiency extraction and rapid quantitative analysis of isoflavone aglycones produced by microbial fermentation.  

Objective: To explore the effects of propolis and iron supplements on iron status and free radical content in blood of exercise rats, and to investigate the antioxidative protection of propolis on oxidative damage derived from exercise and/or iron supplement. Methods: Forty Sprague-Dawley male rats aged 3 months were randomly divided into 5 groups of 8 each: control group (C group), exercise group (E group), exercise plus iron supplement group (EI group), exercise plus propolis supplement group (EP group) and exercise plus supplement with iron and propolis group (EIP group). The rats were subjected to treadmill training with an incremental loading for 6 weeks. Red blood cell indices including red blood cell count (RBC) and hemoglobin (Hb) and hematocrit (Hct), plasma iron status including plasma iron (PI) and total iron binding capacity, and serum MDA and SOD contents of rats were measured. Results: Compared with C group, a significantly lower level of red blood cell indices, iron status and SOD, and an obvious higher level of MDA were observed in E group. Compared with E group, a significantly higher level of red blood cell indices and iron status was observed in rats from EI, EP and EIP groups; meanwhile, MDA content in rats from EI group was higher than that in E group; SOD content in rats from EI group was lower than that in E group. MDA content of rats in EP and EIP groups was lower than that in E group and SOD content of rats in EP and EIP groups was higher than that in E group. MDA content in rats from EIP group was lower than that in EI group and SOD content in rats from EIP group were higher than that in EI group. No significant difference between EP and EIP groups was also observed. Conclusion: Iron supplement can increase the risk of oxidative stress in spite of improving anemia symptom and lower iron status of exercise rats. Propolis can effectively improve the ability of organism to scavenge free radicals, reduce lipid peroxidation, and enhance antioxidant function. Therefore, propolis can improve the exercise-induced or iron-deficient anemia. 

Factor analysis and system clustering were used to study the classification of mirror carps in different seasons based on body parameters and nutritional composition in their back and abdominal muscles. The results showed that the major body characteristics of mirror carps in spring and summer exhibited larger bodies, higher proportion of viscera and lower proportion of skin; in contrast, mirror carps in autumn and winter had smaller bodies, lower proportion of scale and viscera, and higher proportion of fish muscle. The major nutritional characteristics of abdominal muscle from mirror carps in spring and summer revealed lower contents of proteins, free amino acids and ash, and higher content of water; the major nutritional characteristics of abdominal muscle from mirror carps in autumn had higher contents of proteins and ash, and lower content of water; the major nutritional characteristics of abdominal muscle from mirror carps in winter had higher contents of proteins, crude fat and total sugar, and lower content of water. The major nutritional characteristics of back muscle from mirror carps in spring revealed the lower contents of proteins, crude fat, total sugar and ash, and higher contents of free amino acids and water; the major nutritional characteristics of back muscle from mirror carps in summer had lower contents of crude fat and total sugar, and lower contents of free amino acids, ash and water; the major nutritional characteristics of back muscle from mirror carps in autumn and winter had lower contents of crude fat, total sugar and water, and higher contents of proteins, free amino acids and ash.

Multivariate analysis was conducted to evaluate the amino acid composition and nutritional values of 7 types of Chlorella including Chlorella vulgaris, Chlorella autotrophica, Chlorella minutissim, Chlorella spp., Chlorella pyrenoidosa, Chlorella protothecoides and Chlorella ellipsoidea. The results showed all kinds of amino acids were detected in the 7 types of Chlorella. The ratios between essential amino acids and total amino acids were 35.86%, 39.75%, 37.58%, 36.35%, 38.05%, 37.98% and 40.28%, and the essential amino acid indexes were 66.63, 79.41, 67.96, 71.17, 57.69, 70.02 and 65.39 in Chlorella vulgaris, Chlorella autotrophica, Chlorella minutissim, Chlorella spp., Chlorella pyrenoidosa, Chlorella protothecoides and Chlorella ellipsoidea, respectively. Cluster analysis and principal component analysis indicated that Chlorella cultured in seawater-based medium and freshwater-based medium could be classified as two different types according to the contents of amino acids. Three principal components were analyzed to reveal a contribution rate of 73.727% for the first principal component, 10.021% for the second principal component and 7.052% for the third principal component, respectively. The cumulative contribution rate of three principal components was 90.80%.

Objective: To explore the toxicity of sodium selenite. Methods: Wistar rats were used to explore acute toxicity and accumulative toxicity of sodium selenite by the modified Karber method and the dose-increasing method, respectively. In addition, rats administered with sodium selenite at doses of 1/20 LD50, 1/10 LD50 and 1/5 LD50 for 30 consecutive days were used to explore its sub-acute toxicity. The growth status, histopathological change and blood biochemical indices of rats were determined. Results: The LD50 of sodium selenite was 11.75 mg/kg and the accumulative coefficient was 3.3, which revealed a moderate capacity of accumulative toxicity for rats. However, the growth of rats was inhibited when the concentration of sodium selenite was up to 0.588 mg/kg. The major organs including heart, liver, spleen, lung and kidney were damaged to different extents and blood biochemical indices were affected by sodium selenite at high concentrations. Conclusion: Sodium selenite is a material with high toxicity, which can cause acute, accumulative and sub-acute toxicity to rats.

Objective: To explore the effect of Tenebrio molitor oil on blood lipid and antioxidant function in ICR male mice with hyperlipidemia. Methods: High fat diet was used to create a hyperlipidemic model. Fifty healthy male ICR mice were randomly divided into 5 groups of 10 each: normal control group (fed basal diet), high fat model group (fed high fat diet) and low-, middle- and high-dose Tenebrio molitor oil groups (fed high fat diet and administered intragastrically with Tenebrio molitor oil at doses of 5, 10 mL/(kg·d) and 20 mL/(kg·d), respectively). After 30 consecutive days of intragastric administration, all the mice were measured for their body weight, liver index, blood lipid levels and antioxidant function in liver. Results: Tenebrio molitor oil could reduce serum total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) levels as well as arteriosclerosis index (AI), and increase high-density lipoprotein cholesterol (HDL-C) level. It could also reduce the content of malondialdehyde (MDA) content, increase hepatic catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, and improve liver total antioxidant capacity (T-AOC). Conclusion: Tenebrio molitor oil can regulate blood lipid and enhance antioxidant function.

The macronutrients, trace nutrients, amino acid compositon and fatty acid composition of tree spinach grown in Chongqing were determined and compared with those previously reported for tree spinach and other vegetable species in order to understand the change in nutritional composition of tree spinach in a different eco-system and evaluate the nutritional value of tree spinach. The results indicated that tree spinach was rich in proteins, α-linolenic acid, vitamin B1, vitamin B2, vitamin B6, niacin, vitamin C, potassium, calcium, magnesium, iron, zinc and manganese, while the content of sodium was low. Therefore, tree spinach is a kind of new food resource with high nutritional value.

Objective: To investigate the inhibitory effects of total flavones from Vitis vinifer L. on hepatitis B virus (HBV) replication and their toxicity in cultured human hepatocellular liver carcinoma cell line HepG 2.2.15 transfected with HBV DNA. Methods: After 8 days of treatment with total flavones from Vitis vinifer L., the contents of HBsAg and HBeAg in the cell culture supernatant of HepG 2.2.15 were measured by ELISA to calculate the inhibitory rates against the secretion of HBsAg and HBeAg, the change in HBV DNA was monitored by real-time PCR, and cytotoxicity test was performed using MTT assay. Results: Addition of total flavones from Vitis vinifer L. in a dosage range of 12.5 to 100μg/mL could reduce the contents of HBsAg and HBeAg in the cell culture supernatant of HepG 2.2.15 to different extents. Little cytotoxic effect was observed with a median toxic concentration (TC50) of 284.91 μg/mL. The median effective doses (IC50) on HBsAg and HBeAg were 327.56 μg/mL and 215.34 μg/mL, and the therapeutic index for HBsAg and HbeAg were 0.87 and 1.32, respectively. Total flavones from Vitis vinifer L. at 100 μg/mL could inhibit HBV DNA by 47.63%. Conclusion: Total flavones from Vitis vinifer L. have inhibitory effects on HBV in vitro.

Silkworm pupae oil extracted from the waste after silk reeling by supercritical carbon dioxide fluid extraction, which was found to contain 68% of unsaturated fatty acids, was administered intragastrically to normal rats and high fat model rats for 6 successive weeks and then fasted for 12 h after the last administration. The levels of hepatic total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C) and malonyldialdehyde (MDA) and the activities of related lipases such as lipoprotein lipase (LPL) and hepatic lipase (HL) were measured to clarify the effect of silkworm pupae oil on hepatic lipid metabolism and related lipase activity in rats. The results showed that silkworm pupae oil could significantly reduce the levels of hepatic TC and TG, increase HDL-C level, decrease atherosclerotic index and MDA level, and notably improve the activities of LPL and HL. It could be concluded from these results that silkworm pupae oil is capable of regulating lipid metabolism and decreasing blood lipid in rats.

In order to evaluate the protein quality of milk products commercially available in Heilongjiang, protein and non-protein nitrogen contents in sweetened whole milk powder, yoghurt, milk beverage, and sterilized pure milk were determined by micro-Kjeldahl method and trichloroacetic acid precipitation method, respectively, and protein and non-protein nitrogen indexes were calculated. The results showed that it was feasible to evaluate protein quality of milk products based on protein and non-protein nitrogen indexes. Four models for protein and non-protein nitrogen indexes in milk products were established. The protein nitrogen indexes of certified sweetened whole milk powder, yoghurt, milk beverage, and sterilized pure milk were in the range of 0.990 to 0.995, 0.870 to 0.956, 0.402 to 0.633, and 0.929 to 0.943, and the non-protein nitrogen indexes were in the range of 0.005 to 0.010, 0.084 to 0.130, 0.367 to 0.598, and 0.069 to 0.071, respectively. On the whole, protein content of commercially available milk products in Heilongjiang is generally consistent with the national standard, although part of them needs to be improved due to poor protein quality.

Purpose: To understand changes in nutrient and hazardous substances during the growth of unearthed bamboo shoots. Methods: The starting point of the growth period of bamboo shoots from selected bamboo forests under the same cultivation conditions was just before breaking through the soil. Unearthed bamboo shoots with different heights labeled on the same day were harvested and analyzed for their nutrients and hazardous substances. The results revealed that crude protein content basically tended to decrease during the growth of bamboo shoots and decreased by 0.017 mg/(kg·cm) with increasing height. The proportion of essential amino acids occupying total amino acids displayed a gradual increase. No obvious change in crude fiber content was observed. The maximum content of nitrate in bamboo shoots was 175 mg/kg. In the height range of 5 to 15 cm, both nitrite and nitrate contents were less than 10 mg/kg. Conclusion: The nutritional value of unearthed bamboo shoots increases with the extension of growth period, and a very small amount of nitrite is accumulated. Therefore, higher bamboo shoots are a nutritional and safe food.

The purpose of the present work was to study the antioxidant effect of water soluble polysaccharides from Hippophae rhamnoides leaf tea (WPHT), a commercially available product processed from the leaves of the plant, in subacute aging model mice induced by subcutaneous injection of D-galactose. Fifty mice were divided into 5 groups of 10 ones each: blank control group, aging model group, low-dose 10 mg/(kg·d) WPHT group, middle-dose 50 mg/(kg·d) WPHT group and high-dose 100 mg/(kg·d) WPHT group. The aging model group and the low-, middle- and high-dose WPHT groups were all injected with D-galactose (0.5 g/(kg·d)) subcutaneously for 40 consecutive days, and normal saline instead of D-galactose was given to the blank control group. Intragastric administration of WPHT began after 10 days of subcutaneous injection of D-galactose, was carried out once a day and lasted 30 days. All the mice were fasted for 12 hours after the last intragastric administration of WPHT, and were then scarified to determine the activities of plasma superoxide dismutase (SOD), the content of malondialdehyde (MDA) in plasma, and the activities of SOD, catalase (CAT) and MDA content in liver homogenate. The results revealed that WPHT administration at 50 mg/(kg·d) and 100 mg/(kg·d) could elevate the activities of plasma SOD and liver homogenate SOD and CAT and decrease the contents of plasma MDA and liver homogenate MDA, with a significant difference from the model group (P ＜ 0.05). Therefore, WPHT has antioxidant potential in vivo.

Objective: To study the effects of quercetin (Que) and apigenin (Api) at the same dose on blood uric acid and antioxidant capacity in hyperuricemic rats induced by adenine combined with ethambutol hydrochloride. Methods: SD rats were divided into 5 groups, normal control, model control, allopurinol group, Que group, and Api group. Hyperuricemia and renal failure in rats were induced by adenine and ethambutol hydrochloride tablets intragastrically, and then Que and Api were separately administrated for 3 weeks. Enzyme activity and serum biochemical indicators in liver and serum were measured at the end of 21-day administration. Results: Que and Api could effectively lower the levels of serum uric acid (SUA), serum urea nitrogen (SUN), serum creatinine (SCr) and malondialdehyde (MDA), and elevate the activity of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) in serum and liver. Conclusion: Que and Api can reduce serum uric acid and lipid peroxidation level so as to improve antioxidant and free radical scavenging capacities in hyperuricemic rats.

Purpose: To investigate the hypoglycemic effect of Chaya leaf total flavonoids extract (CLTFE) on alloxan (ALX)-induced diabetic rats. Methods: A total of 44 rats were randomly divided into normal control group (normal feed), model control group (ALX), drug treatment control group (ALX + Metformin hydrochloride) and CLTFE treatment groups (ALX + CLTFE at the high and low dosages of 0.21 g/kg and 0.14 g/kg, respectively). The serum levels of fasting blood glucose (FPG), oral glucose tolerance test (OGTT), glycosylated serum protein (GSP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) of rats in each group were determined after consecutive feeding for 28 days. Results: CLTFE significantly reduced the serum levels of FPG, OGTT, GSP, ALT, AST, BUN, TG and LDL-C (P＜0.05) in ALX-induced rats, and significantly increased the serum level of HDL-C and body weight of ALX-induced rats (P＜0.05). Conclusion: CLTFE can improve the situation of weight loss in diabetic rats, and have auxiliary hypoglycemic effect in alloxan-induced diabetic rats.

In order to explore the hepatoprotective effect of peanut peptide (PP) on D-galactose (D-Gal)-induced liver damage in rats, fifty rats were randomly divided into five groups designated as control group, model group and three PP-treated groups. Except for the control group, the other groups were subcutaneously injected with D-Gal solution at a daily dosage of 400 mg/kg for 50 successive days to establish oxidative damage model. Meanwhile, rats in PP treatment groups were orally administered with PP at dosages of 200, 500 mg/kg and 800 mg/kg, respectively. The biochemical index, lipofuscin (LF) content, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities in liver were analyzed. In addition, histopathological characters in liver tissues were observed under a light microscope. The results showed that a D-Gal-induced rat model with liver damage was successfully established. PP significantly decreased the levels of TBA, ALT and ALP in serum and LF in liver, and obviously increased the levels of SOD, GSH-Px and CAT in liver in a dose-dependent manner. Furthermore, the histopathological characters of liver tissues in PP treatment group at high dosage were close to those in the control group. Therefore, PP has an excellent protective capability against liver damage in D-Gal-induced rats.

Frost in chocolate can result in the decrease of product quality, which is a worldwide problem in the confectionery industry. The mechanisms of frost in chocolate are varied as the change of matrix oil types. In this article, the effects of matrix oil compositions, processing conditions and storage conditions on frost in chocolate have been discussed. Meanwhile, the possible mechanisms of frost in chocolate have been summarized. Moreover, the corresponding strategies for attenuating the formation of frost in chocolate have also been proposed. All of these investigations will provide a theoretical guidance for chocolate production.

Myofibrillar proteins are a kind of proteins, which reveal an important effect on water-holding capacity, texture properties and sensor quality of foods due to the functional properties of myofibrillar proteins. Glycosylation is an effective method to modify proteins, which have a wide range of application prospects. In this paper, the mechanisms and methods of glycosylation reaction between myofibrillar proteins and reducing sugars, and enhanced effect of glycosylation on solubility, emulsion and thermal stability have been reviewed. The future research directions have also proposed.

The wine aroma is mainly due to complex reactions between aroma components as well as aroma components and non-aromatic matrix components. Chemical components for grape and wine aroma have been comprehensively studied, which is focused on the complexity of volatile aromatic compounds responsible for wine aroma, and their changes caused by different grape varieties, growing areas and wine age. In this article, the types of aroma components in wine, corresponding factors, analytical methods and applications are reviewed.

Metabolomics can quantitatively evaluate subtle dynamic change of metabolic pathways in organisms resulting from external stimuli including diets, living habits, bioactive substances and intestinal flora. It also provides a promising strategy to explore personalized nutrition, nutritional diseases and nutritional epidemiology. Therefore, metabolomics has been widely applied to nutrition research. In this article, metabolomic applications in nutrition research is briefly reviewed.

Marennine, a kind of water-soluble azure polyphenol pigment produced by marine diatom—Haslea ostrearia, can enhance the green color of oysters   gills and labial palps and increase the economic value. Studies on marennine involved in its physicochemical properties, chemical structure, biological activity, purification and determination methods are discussed in this paper. Haslea ostrearia is the only marennine-producing marine diatom from Bacillariophyta. Moreover, the productivity and accumulation of marennine are affected by irradiation, nutrients, temperature, algal competition, interaction between algae and oysters. Bioreactors are also used to cultivate Haslea ostrearia under the controlled conditions for achieving high yield of marennine.

Electrical impedance refers to the ability of media to impede current in circuit. When the texture structure of muscle has been changed, the capability to impede current will also change. The quality of meat can be fast and accurately controlled on the basis of the relationship between electronic impendence parameters and meat quality parameters. In this paper, the basic principle of electrical impedance technology is introduced. The applications of electronic impedance technology in detecting pH change in bovine, pork carcass rigor mortis and aging process, controlling the aging process and evaluating intramuscular fat are also discussed. Meanwhile, the future development trend of electronic impedance technology is proposed, which will provide a reference for the quality control of meat by electronic impedance technology.

Fatty acids produced by oil-producing microorganisms are stored in cells as the form of triglyceride. The extraction of these fatty acids from the cells is involved in complex processing, high production cost and serious environmental pollution. Targeted regulation for the production of free fatty acids by engineered E. coli strains is becoming one of the hottest topics in current research, which will be an effective strategy for reducing energy crisis and providing high-quality and low-cost raw materials of oil. The research progress of some genes (tesA, fadD and fadL) and regulatory protein (MsbA) related to extracellular secretion of fatty acids in E. coli has been reviewed in this paper. Meanwhile, the target regulation of fatty acid metabolism by using molecular biology and metabolic engineering strategies has been proposed, with the aim of provideing a new direction for producing extracellular fatty acids.

The phenolic compounds in carya (Carya cathayensis) include a big category of compounds. They play a key role in stabilizing the taste, as well as maintaining the secondary metabolites that are involved in a variety of physiological activities and protecting carya from physical damages. Previous studies on the antioxidant activities of carya phenolic compounds were focused on the extraction and purification of total polyphenols and the identification of individual compound. This paper reviews the progress of the domestic and foreign researches on extraction, purification, and antioxidant activities of total polyphenols from carya in recent years, in order to provide a reference for the comprehensive utilization of functional compounds in carya and other nuts.

Surface plasmon resonance (SPR) has been widely applied in various fields owing to its simplicity, low cost, no labeling, high selectivity, and real-time monitoring. SPR can be used not only for detecting analytes, but also determining kinetic parameters of molecular interactions. Interest in the development of SPR based immunosensors for the detection of low molecular weight pesticides in foods and environment has been rapidly increased over the last ten years. In this paper, the SPR principle and instrument types are briefly introduced. The category of recognized molecules immobilized on the SPR sensor surface, detection methods and their applications in pesticide detection are introduced emphatically. In addition, trends of SPR in the area of pesticide detection are also prospected.

β-Agonists can increase protein synthesis rates and promote animal growth, but its residues in foodstuffs of animal origin may pose health risks to human. Most of β-agonists are banned to be used in animal feeds, and many countries have passed a series of laws and regulations to limit the use of β-agonists in animal feed and to enhance the control and monitoring of β-agonists used in farm animals. This article discusses the safety issues of β-agonist residues in foodstuffs of animal origin and compares the regulations on β-agonists among main international organizations and countries including Codex Alimentarius Commission, EU, USA, Japan and China, and summarizes the technologies used for qualitative and quantitative analyses of β-agonists.