The pH effect on the oxidation of (+)-catechin was investigated in B-R buffers at pH range from 1.8 to 11.5. During the potentiostatic oxidation, the dynamic UV-Vis spectra were recorded in a long-optical-path thin-layer cell. The natural chemical oxidation of (+)-catechin in alkaline media was also examined in the same cell for the purpose of comparison. The results showed that the electro-oxidation of (+)-catechin abides by transformation polymerization mechanism, in which the following polymerization steps are accelerated and the electro-oxidation steps are inhibited at higher pH. Moreover, the oxidation products of (+)-catechin vary markedly with pH values of media. In acidic media the products are catechin dimmers, whereas in alkaline media they are possible oligomers with different degrees of polymerization. Controlled by O2 concentration, the natural oxidation of (+)-catechin is slower than the electro-oxidation in the same alkaline medium but they lead to the same products.

Rapid viscosity analyzer (RVA) was used to determine viscosity profiles of cereal, tuber and legume starches, and the correlation between starch digestibility and RVA profile characteristics was investigated in this study. The results showed that the total breakdown values of different starches are positively correlated with rapidly digestible starch (RDS) (r=0.741, p＜0.01) but negatively correlated with slowly digestible starch (SDS) (r=－0.833, p＜0.01). For cereal starches, the breakdown value of hot paste is positively correlated with RDS (r=0.970, p＜0.01) but negatively correlated with SDS and resistant starch (RS) (r=－0.906, p ＜ 0.05; r= － 0.978, p ＜ 0.01, respectively). For tuber starches, the breakdown value is negatively correlated with SDS (r=－ 0.987, p ＜ 0.05) but positively correlated with RS (r=0.989, p ＜ 0.05). For legume starches, the breakdown value is negatively correlated with SDS (r=－1.000, p＜0.05), but the gelatinization temperature is positively correlated with RDS (r=0.998, p＜0.05).

In this study, static adsorption capacity and desorption rate were measured to confirm the optimum manipulation parameters of macroporous resin for separating angiotensin converting enzyme inhibitory peptide (ACE-inhibitory peptide). The results showed that the best pH of sample for the desalination of ACE-inhibitory peptide is 2.0, and when 70% ethanol is used as eluent, the elution effect is the best and the salt concentration of sample is kept constant. In conclusion, DA201-C macroporous resin has excellent and comprehensive adsorption property, and can be used to separate ACE-inhibitory peptide.

Thermal properties of agricultural products are key factors affecting their deep processing technology, especially the thermal conductivity is most important. Based on comparison of present measurements, the spherical measurement was adopted in this study to determine the thermal conductivities of rice, mung bean and soybean powders. Finally the equations between thermal conductivity and temperature and between thermal conductivity and nutrition content were obtained by regression analysis. The results showed that the thermal conductivities of rice and mung bean powders decrease with the increase of temperature, while that of soybean increases with the increase of temperature, furthermore all of them increase with the increase of nutrients except water.

In this study, 205 samples of fried instant noodles from 12 main brands, which occupy 80% to 90% market in mainland China, were collected to explore a new thinking for evaluating the quality of fried instant noodles. At the first stage, K-mean algorithm was applied to analyze sensory evaluation scores of eight sensory evsory evaluation indexes. Secondly, based on the results of clustering analysis at the first stage, a model of quality evaluation with fifteen physical indexes was built by means of decision tree. The final results of this study showed that this model for quality evaluation can achieve a prediction accuracy of 95.61% and successfully demonstrat the relationship between sensory evaluation and machine measurement values. In conclusion, it can provide an objective and quantification method to evaluate the quality of fried instant noodles.

It was found experimentally that when the ratios of ethanol to ether and Trichosanthes kirilowii Maxim. peel to ethanol-ether are 1:1 (V/V) and 1:15 (g/ml) respectively, the extraction efficiency of Trichosanthes Kirilcwii Maxim. peel pigment reaches the highest. The spectrum analysis indicated that Trichosanthes kirilowii Maxim peel. pigment is stable at pH 2 to 5 and below 60 ℃, and high concentrations of sucrose and glucose can protect its color. However, Fe3+ has more negative effects on the pigment than Zn2+ and Ca2+, and its degradation may be accelerated under sunlight.

Glucosamine sulfate samples were heated at 60, 70, 75 and 80 ℃ for 10 h, respectively. The changes in browning index (absorbance at 420 nm), contents of 5-hydroxymethyfurfural (5-HMF) and glucosamine sulfate and pH value were determined to estimate the extent of nonenzymatic browning during the heating process. Then zero-order kinetics was applied to describe the results. It was found that with the increase of heating temperature and time, 5-HMF content and browning index increase, while glucosamine sulfate content and pH value decrease. The nonenzymatic browning reactions of glucosamine sulfate accord with zero-order kinetics model, and the activation energies of changes of browning index and 5-HMF content are 85.127 kJ/mol and 136.973 kJ/mol, respectively. Moreover, NaHSO3 shows certain inhibitory effects against nonenzymatic browning of glucosamine sulfate.

Lizardfish is considered as one kind of low-market-value fish in Southeast Asia due to their appearance and susceptibility to spoilage. Presently, most studies focus on the gel-forming ability of Saurida, while no information regarding gelforming ability of Trachinocephalus myops is available. Effects of various hydrocolloids on the gel properties and rheological properties of Trachinocephalus myops surimi gels were investigated by texture analysis and dynamical rheological measurement, respectively, in this study. The results showed that additions of various hydrocolloids have different effects on the gel-forming properties of Trachinocephalus myops surimi. Carrageenin and agar can increase the break force of Trachinocephalus myops surimi gels, xanthan gum can decrease the break force, while alginate and konjac gum have slight negative effects on the break force. The addition of anyone of these hydrocolloids would decrease the deformation of Trachinocephalus myops surimi gel.

In this study, effects of various abiotic factors such as acid solutions (acetic acid, nitric acid， hydrochloric acid and citric acid), metal ions (Zn2+, K+, Fe3+ and Cu2+), ionic strength ( with Na+ ion intensity as the reference: 0, 0.2, 0.4, 0.6 and 0.8 mol/L) and pH value (4, 4.5, 5, 5.5 and 6) on the antibacterial activity of nisin against Staphylococcus aureus, a representative pathogeic bacterium in foods, were investigated. The results indicated that the effects of different acid solutions on the antibacterial activity of nisin are different, among which acetic acid shows the best improvement effects on the antibacterial activity of nisin; The addition of above metal ions can increase the antibacterial activity of nisin, among which K+ presents the strongest effect; The increase of ionic strength also can improve the antibacterial activity of nisin; Moreover， in the environment of pH 4.0 nisin plays the strongest antibacterial activity.

The variation of physicochemical characteristics and the growth and decline regularity of microbe of fermented loin ham were investigated in storage process. The results indicated that lactic acid bacteria are in advantage state and always keep high level in the processing of fermented loin ham. The lactic acid bacteria at relatively high level suppress the growth of undesired bacteria effectively, improve the product quality, and prolong the storage period of the products. During the fermentation process, although the total contents of free amio acids and fat acids do not vary obviously, the contents of Thr, Ala, Glu, Ile, Leu and Val as well as the contents of C18:2 and C18:3-α significantly increase, while that of C18:1 decreases. Moreover, the acid fermentation environment promotes the degradation of nitrite and reduces the residue of nitrite in products. Compared with the control group, the contents of TVB-N and TBA are lower in both of fermentation and storage stages.

Crude pumpkin polysaccharide was obtained by hot water extraction, and then the pumpkin polysaccharide AP1 was separated from the precipitate by cetyltrim-ethlammonium bromide (CTAB) method. The content of uronic acid in pumpkin AP1 polysaccharide was determined by spectrophotometric method with galacturonic acid as reference susbtance, its relative molecular weight was determined by high performance gel permeation chromatography (HPGPC), and its chemical structure was analyzed by the techniques of ultraviolet-visible spectrometry, infrared spectrometry, gas chromatography and atomic force microscopy (AFM). The determination results of spectrophotometer and HPGPC respectively showed that the content of uronic acid is 38.87%, and the molecular weight is 2.0×105 D. The ultraviolet-visible spectrum indicated that there are no protein and no nucleic acid in pumpkin polysaccharide AP1. The gas chromatogram indicated that it is composed of arabinose, rhamnose, ribose, fructose, galactose and glucose. The infrared spectrum suggested that there are characteristic absorption bands of polysaccharide in pumpkin polysaccharide AP1, and its monosaccharide residues exist in the forms of pyran and furan rings. AFM revealed that it has a multi-branched structure and various small rings or helical structures in linkages of adjacent monosaccharides.

With catechol as substrate, the change laws of reaction kinetics of apple polyphenol-oxidase (PPO) induced by alternating magnetic field were studied. The results indicated that the reaction kinetic of apple PPO browning is in accordance with Michaelis equation, and the Km and Vmax are 0.000687 mol/L and 0.0477 U/min, respectively. When the magnetic field strength is less than 0.87 A/m, the reaction system shows to be promoted; When the magnetic field strength is 1.67 A/m, the reaction system shows to be promoted by less 3-h treatment and to be inhibited by over 3-h treatment; When the magnetic field strength is more than 1.67 A/m, the reaction system is inbibited regardless of treatment time. Furthermore, the inhibitory effect of magnetic field increases with the increase of its strength. However, when the treatment time is over 1 h at the same strength, the effect of magnetic field tends to steady even if the treatment time extending. When the magnetic field strength is 4.22 A/m, it shows the strongest promotion effect on the PPO reaction system at 0.5 h and gradually presents the inhibitory effect after 0.5 h; Over 1 h, its inhibitory effect becomes steady with the Km of 0.0108 mol/L and Vmax of 0.0146 U/min. In conclusion, alternating magnetic field is able to inhibit the affinity of enzyme to substrate and decrease the maximum reaction velocity.

The peptide from Rana chensinensis skin has broad antibacterial spectrum, and may inhibit Gram-negative, Grampositive bacteria and yeast. The antibacterial activity also shows fairly strong thermal and acid stabilities. But when pH value is above 8, the antibacterial activity disappears. Compared with the intact cell wall of Bacillus subtilis in the control group, the broken and perforated phenomena of cell wall of Bacillus subtilis treated with the peptide was detected with scanning electron microscopy (SEM), which suggested that the antibacterial mechanism of the peptide from Rana chensinensis skin is to damage bacterial wall and result in cytoplasm outflow and bacteria death.

Crude polysaccharides were extracted from chicken keel cartilage by papain enzymolysis, deproteination of trichloracetic acid and ethanol precipitation, and then they were further purified by DEAE-Sepharose Fast Flow ion exchange column chromatography and Sepharose 6B Fast Flow gel column chromatography. Finally the scavenging activities of various fractions to hydroxyl radicals were compared. The results exhibited that the activity of crude polysaccharides precipitated by alcohol is significant higher than that of crude polysaccharides after preliminary dialysis. In addition, chondroitin sulfate and other 5 kinds of polysaccharides (non-glycosaminglycan) were obtained from the crude polysaccharides by DEAE-Sepharose Fast Flow ion exchange column chromatography and Sepharose 6B Fast Flow gel column chromatography. The scavenging activities of these 5 kinds of polysaccharides to hydroxyl radical are higher than that of chondroitin sulfate.

Through the measurement of total antioxidant capability (T-AOC), 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavening ability and inhibitory ability against oxidation of linoleic acid, the antioxidant activities of water soluble proteins (WSPs)in royal jelly and their hydrolysates were investigated. The results indicated that although WSPs have no obvious antioxidant activity, their activity significant increases after hydrolyzed, especially the product PT-WSPs from WSPs hydrolyzed by both pepsin and trypsin shows the highest antioxidant activity. Furthermore, the membrane separation of WSPs and their hydrolysates were conducted. It was discovered that small peptides with molecular weight of lower than 3 kD, especially lower than 1 kD, have powerful T-AOC, DPPH radical scavenging ability and inhibitory ability against oxidation of linoleic acid.

Through the determination of surimi gel properties and solubility, this study aimed to investigate the effect of soy protein isolate (SPI) on the formation of microbial tranglutaminase (MTGase)-induced silver carp surimi gel and understand the mechanism using SDS-PAGE and SEM. The results showed that both of SPI and MTGase significantly increase surimi gel properties, but the addition of SPI may inhibit myosin heavy chain (MHC) cross-linking induced by MTGase and enhance the solubility of surimi gel. The mechanism of SPI improving surimi gel properties may result from its inhibition against protease activity and own gelation.

The total flavonoids of Emilia sonchifolia were extracted by ethanol refluxing and separated by polyurethane column, and their scavenging activities to 1,1-diphenyl-2-picrylhydrazyl (DPPH·) and hydroxyl radicals were measured by spectrophotometry. The results showed that the obtained products from Emilia sonchifolia are total flavonoids confirmed by thin layer chromatography, the separation effect of total flavonoids from Emilia sonchifolia is satisfying, and the total flavonoids present good scavenging activities to DPPH· and hydroxyl radicals with the IC50 values of 4.8×10-3 mg/ml and 0.53 mg/ml, respectively.

The effects of soy sauce, water, salt, sugar, sousing time and steaming time on the texture characteristics of steamed pork bacon with rice powder were investigated. The results showed that soy sauce has little influence on springing, cohesiveness and resilience of fat meat with skin; water is the main factor affecting cohesiveness and chewiness of fat meat with skin and springing and chewiness of skinless fat meat; salt mainly affects cohesiveness of fat meat with skin and resilience of skinless fat meat; sugar is the main factor affecting hardness and resilience of skinless fat meat; sousing time mainly affects hardness and chewiness of fat meat with skin and resilience of skinless fat meat; steaming time is the main factor affecting springing and cohesiveness of fat meat with skin and springing and resilience of skinless fat meat. Moreover, soy sauce, sousing time and steaming time have little effects on springing of lean meat. Except water, all of soy sauce, salt, sugar, sousing time and steaming time may cause the significant change of hardness of learn meat.

The stagewise degradation process of G. heterophylla polysaccharide gum assisted by microwave was studied. Through the coupling of microwave treatment with strong oxidizer and KOH, as well as β-mannanase hydrolysis, the high viscosity of the gum was degraded to a lower level, with the concentration increasing from 1% to 10 %. After β-mannanase hydrolyzing the gum for 24 h, the content of galacto-mannan-oligosaccharides is up to 73.8%, while the content of monosaccharide is 26.23%.

The rheological properties of mashed sweet potato were studied by using HAKKE viscometer at different temperatures and concentrations of dry substrate. The results showed that mashed sweet potato is typical pseudoplasticity fluid, and its flow behaviour can be preferably described by the power law model. Its apparent viscosity decreases with the increase of temperature and shear rate, and presents shear thinning tendency. For predicting the apparent viscosity of mashed sweet potato, this study developed some useful mathematical models with temperature and substrate concentration as influence factors. Through the evaluation of various statistical parameters such as mean percentage error, chi-square, modeling efficiency, these models were proved to have high fitting precision.

With epichlorohydrin as crosslinker and chloroacetic acid as carboxymethylation reagent, a cross-linked carboxymethyl cassava starch was synthesized and its absorption effects on Ca2+ were investigated. The results showed that the crosslinked carboxymethyl cassava starch can effectively remove Ca2+ from the aqueous solution, and the Ca2+ adsorption quantity is related to starch substitution degree, starch amount, initial Ca2+ concentration, reaction time, reaction temperature and pH value.

The contents of main nutritional components and amino acids of Bohu mushroom were detected, and the international general nutritional value assessment method was applied for the overall nutritional assessment of its protein. The assessment result showed that, compared with button mushroom (Agaricus brunnescens), shiitake mushroom (Lentinus edodes), straw mushroom (Volvariella volvacea) and oyster mushroom (Pleurotus rhodophyllus), the total content of essential amino acids in Bohu mushroom is the highest, which occupies 43.9% of the total amino acids. Moreover, its amino acid score (AAS), chemical score (CS), essential amino acid index (EAAI), biological value (BV), nutritional index (NI) and score of ratio coefficient of amino acid (SRCAA) of protein are 68.6, 43.6, 78.6, 74.0, 32.6 and 65.3, respectively. By the measurement of fuzzy discernment method, its close degree to egg protein is 0.89, which is higher than that of button mushroom, shiitake mushroom, and straw mushroom. In conclusion, the protein nutrient value of Bohu mushroom is very high.

In the process of preparing heat-induced gel of salt soluble protein from longissimous dorsi (LD) or biceps femoris (BF) of yellow cattle in Yunnan Province, NaCl concentration, temperature and pH affecting the water holding capacity (WHC) of heat-induced gel were optimized through orthogonal test coupled with variance analysis, respectively. The results showed that for both LD and BF, the optimal preparation conditions of heat-induced gel are NaCl concentration 0.6 mol/L, 70 ℃ and pH 7.0, and the corresponding WHCs of heat-induced gel are 96.21% and 96.35%, respectively. The SDS-PAGE pattern and scanning electron microscope (SEM) image showed that the myosin content in extracted salt soluble protein under the above conditions is higher, and the prepared heat-induced gel network is uniform, dense and smooth.

In simulated gastric juice, the scavenging activity of purple sweet potato anthocyanin to nitrite was determined by spectrophotometry, and effects of reaction time, temperature, anthocyanin amount and food additives on the scavenging rate were investigated in this study. The results showed that the scavenging activity of purple sweet potato anthocyanin to nitrite increases following with the increase of reaction time, temperature and anthocyanin amount. Adding 0.05% VC, 0.05% VE or 0.05% VC plus VE into the purple sweet potato anthocyanin solution can increase its scavenging activity to nitrite at different degrees.

Objective: To study the antimicrobial activity of Chenopdium album L. extract in vitro. Methods: Chenopdium album L. was extracted with 65% ethanol, and then vacuum concentration was conducted to remove ethanol. Finally the concentrate was extracted with petroleum ether, chloroform and ethyl acetate, separately. The effects of different solvent extracts against seven species of pathogenic microorganisms were determined by the methods of agar diffusion and minimal inhibitory concentration (MIC). Results: The petroleum ether extract and chloroform extract have no obvious inhibition effects against seven species of pathogenic microorganisms. However the ethyl acetate extract has strong antimicrobial activity, whose MICs against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Enterococcus faecalis and Candida albicans are less than 1.56 mg/ml, 3.13 mg/ml, 6.25 mg/ml, 6.25 mg/ml, 12.5 mg/ml, more than 50 mg/ml and more than 50 mg/ml, respectively. Conclusions: The ethyl acetate extract has strong inhibition effect against bacteria except fungus. And It has stronger activity against G(-) bacteria than against G(+) those.

In this study, it was found experimentally that adding 0.2% flaxseed gum in the formula of low-temperature chicken sausage can decrease obviously the leaking rate of water and fat. With the increase of water and fat in the formula, the hardness and adhesiveness of chicken sausages decrease, and the sensory quality also decreases a little, but the springiness and cohesiveness change very little. The orthogonal test results showed that both of water and fat may be increased by 5% to 10% when 0.2% flaxseed gum added in the formula, and flaxseed gum should be dissolved before added with the particle size of 50 mesh.

The spherical multinuclear microcapsules of peppermint oil were prepared by complex coacervation, and the effects of various process parameters on the heat resistance of microcapsules were investigated. When core to wall ratio, wall material concentration and pH value are lower than 2:1, 1% and 4.0 respectively, the microcapsules with stronger heat resistance can be obtained. Moreover, the heat resistance of microcapsules increases following with the amount increase of bridged agent formaldehyde. Also, transglutaminase can be used instead of formaldehyde to produce highly heat-resistant and edible microcapsules.

In this study, the inhibitory effects of usnic acid against Staphylococcus aureus, short-chain Bacillus, Bacillus subtilis, Bacillus thuringiensis and E. coli were investigated, and the bacteriostasis of usnic acid was compared with that of benzoic acid and sorbic acid. The results showed that the bacteriostasis of usnic acid is superior to that of benzoic acid and sorbic acid; the minimal inhibitory concentrations (MIC) of usnic acid against these bacteria are 0.557, 0.525, 0.557, 0.500 and 1.76 mg/ml, respectively; the inhibitory effects of usnic acid against these bacteria decrease in the following order: Staphylococcus aureus ＞ short-chain Bacillus ＞ Bacillus subtili ＞Bacillus thuringiensis ＞ E. coli.

The fusion gene of sCT and CGRP was designed according to the principles of genetic engineering method and the bias codon used by plant. An AMV RNA4 5＇-UTR sequence and a 6×His tag were added before the gene, and the Gly was added at the end of the fusion gene. The fusion gene was obtained from pUC(AMV / CGRP / msCT) by Sac I and Sma I digestion, then cloned into plant expression vector pBI121 by T4 DNA ligase to construct recombinant plasmid pBI AMV / CGRP / msCT, and transformed into E.coli DH5α to be kept. The gene sequencing indicated that the expression vector pBI AMV / CGRP / msCT has been successfully constructed.

The kinetic parameters of xanthan gum fermentation production such as cell density of Xanthomonas campestris XG-101 (OD650 nm), xanthan gum concentration, viscosity, average molecular weight, pyruvic acid functional groups and residual sugar, were determined in three different mixing systems. This study proved that in cold model test, the systems of combined impellers (above: double-folded blade downflow disc turbine; below: six-blade Brumajin) and maxblend impeller have high gas hold-up and superior mass transfer performance, which can provide important theoretical guidance for improving industrial fermentation yield and quality of xanthan gum.

A new mutant strain GL-5 was obtained from the high-pressure mutant strain G-39 of Rhodotorula glutinis by N+ ion implantation. Its β-carotene yield is up to 17.36mg/L, higher 80.08% than that of the initial strain G-39. Its optimum medium (glucose 40 g/L, peptone 30 g/L, yeast extract 10 g/L, tomato extract 3 ml/L, riboflavin 0.5 ml/L, inoculation amount 50 ml/L, culture broth quantity 50 ml in 250-ml shake flask and initial pH 6.0) for producing β-carotene was obtained by uniform design experiment. Under the above culture conditions, the yield of β-carotene produced by the mutant strain GL-5 reaches 34.21 mg/L, higher 98. 09% than the control. This study suggested that the mutant strain GL-5 is an excellent strain for producingβ-carotene and has bright application prospect in biochemical engineering.

Based on the amplification of the internal transcribed spacer (ITS) sequence with the primers of ITS1 and ITS4, the suspected “Baiyangdu” strain was identified. The results showed that the ITS sequence of 26 strains (15 P. eryngii and 11 P. nebrodensis) registered in GenBank has similarity of 99% to that of“ Baiyangdu” strain. According to the criterion of ITS sequence analysis and characteristics of white pileus and reticulate lamella, the“ Baiyangdu” is identified as a highly affinis strain of P. nebrodensis and P. eryngii.

The mutagenesis of Mycobacterium sp. BD-696 was induced by UV and DES, and two mutants Mycobacterium sp. BD-696-3 and Mycobacterium sp. BD-696-6 were obtained. When the concentration of substrate steroid is 6‰ and shaking flask fermentation is kept for 168 hours, the transformation yield of androst-4-ene-3,17-dione (AD) from rapeseed sterol by Mycobacterium sp.D-696-3 and Mycobacterium sp. BD-696-6 are 2.31 g/L and 2.33 g/L, respectively, and the corresponding transformation rates are 60.7 % and 61.4%, higher 12.8% and 13.5% than that by the original strain, respectively. Moreover, the continuous passage experiment showed that the mutant BD-696-6 has high genetic stability.

In this study, the purification and identification of extracellular polysaccharides (EPS) from S. thermophilus KLDS 3.0207 were conducted using Sepharose CL-6B gel chromatography and polyacrylamide gel electrophoresis. It was proved that the optimized extraction technology in the prophase can meet the request of EPS function analysis.

In this study, the bioaccumulation and biotransformation of Cr (III) in Spirulina platensis were analyzed by ICPMS- HPLC, and the effects of Cr (III) on the growth of Spirulina platensi were also investigated. The results showed that Spirulina platensis may effectively accumulate and transform Cr (III), and the total Cr enrichment amount and organic degree of Cr reach 173.17 mg/g and 96.99%, respectively. The ICP-MS-HPLC analysis also indicated that no toxic Cr (VI) is generated during the culture process. Moreover, the determination results of dry weight and morphology revealed that the low concentration (less than 234.38 ×10-6 g/g) of Cr (III) may promote the growth of Spirulina platensis, but the high concentration (more than 234.38 × 10-6 g/g) of Cr (III) not only inhibits the growth of Spirulina platensis but also results in its abnormal modality. In conclusion, Spirulina platensis can effectively accumulate Cr (III) in a certain range and be taken as nutritional and safe food for the supplement of Cr (III). Furthermore, it may be used to eliminate the environmental pollution of Cr (III) due to its abilities of anti-high-pressure and absorption capacity to high concentration of Cr (III).

Diversity of genomic DNA of ten cultivated strains of Pleurotus nebrodensis was analyzed by RAPD (random amplified polymorphic DNA). 52 DNA fragments were amplified from 4 selected primers, among which 44 were polymorphic bands with 84.6% of polymorphic site frequency. The result indicated that the DNA fingerprint profiles of the ten strains of Pleurotus nebrotensis are greatly diverse. Moreover, the genetic distance among strains was calculated and the phylogenetic tree was constructed by Popgen32 software. Further, the genetic relationship of the ten tested strains was identified on molecular level, which can provide important scientific basis for accurate classification of Pleurotus nebrotensis.

Two 3-deoxy- α -arobino-heptulosonate-7-phosphate synthase (DS) genes from Corynebacterium glutamicum AS10111, and its alanine and tyrosine auxotrophic and anti-trimethyl-tryptophane mutant C. glutamicum JLC1 were cloned and sequenced. The recombinant plasmid pZ8-1-DSM was constructed by using the DS gene from C. glutamicum JLC1 and expressed in transformed C. glutamicum JLC1. The results showed that the DS activity of recombinant C. glutamicum JLC1  (pZ8-1-DSM)is 5.9 and 7.3 times of that of the host and C. glutamicum wild-type strains, respectively, and its L-tryptophan yield reaches 14.9 g/L, highter 65% than that of the host strain. In conclusion, the DS activity and L-tryptophan yield can be effectively improved by over-expression of DS gene in Corynebacterium glutamicum.

The primary factors affecting protoplast preparation and regeneration of Cordyceps sinensis were discussed with orthogonal analysis in this study. The results showed that the optimum preparation and regeneration process is as follows: digesting mycelia, which has been cultured for 3 d with 2.0% lywallzyme and 1.0% snailase at 32 ℃ for 2 h, with 0.6 mol/L KCl and 0.6 mol/L mannitol as osmotic pressure stabilizers for protoplast preparation and regeneration media respectively. Under the above conditions, the protoplast yield and regeneration rate reach 2.98 × 108/ml and 42.09 × 10-2, respectively.

Cordyceps sinensis mycelia and polysaccharides were prepared by liquid fermentation with the medium of sucrose yeast extract. Through investigating effects of fermentation conditions on their yields, the optimum inoculation quantity, ventilation volume, fermentation temperature and time were confirmed as 5%, 1 L/min, 26 ℃ and 4 days, respectively.

To study gene characteristics of shrimp allergen and discuss the mechanism of food allergy, part of Chinese shrimp (Penneropenaeus chinensis) allergen gene was cloned, and its sequence, effective codes, base composition, codon preference as well as amino acid composition of allergen protein were determined. The results showed that the length of shrimp allergen gene is 1034 bp, the allergen protein is composed by 641 amino acids and the codon preference is high. According to the homology comparison between gene and amino acid sequences, the allergen protein of Chinese shrimp is highly similar to that of other sea crustaceans. This might be one of the important reasons to lead to the occur of activity cross reaction among allergen proteins in various seafoods.

With inluin as the reaction substrate, the effects of pH value, temperature, substrate concentration, metal ion and reaction time on the activity of inulinase from Penicillium sp.B01 were investigated. The results showed that the maximal inulinase activity may be observed at 55 ℃ and pH 4.6; under the conditions of pH 4.6 to 5.4 and below 60 ℃, the inulinase activity is stable; Ca2+ promotes the inulinase activity, but Cu2+ significantly inhibits it. Moreover, the crude inulinase of Penicillium sp.B01 was separated by native-polyacrylamide gel electrophoresis (native-PAGE), and six distinct protein bands were obtained. Then the seperated inulinase was tested with inulin and triphenyl tetrazolium chloride (TTC) was used for activity staining. But only three bands were found to have inulinase activity. The analysis of reaction product by TLC and HPLC further proved that these three bands have the exoinulinase activity, and confirmed that the main composition of reaction product is fructose.

Through the determination of hydrolysis circle size and activity of protease, ten strains of psychrophile producing thermotolerant protease in milk were screened out by singleness-substrate plate separation and Folin methods. Based on their morphology, staining reaction and, cultural characteristics, physiological and biochemical characteristics, the ten strains were identified to belong to Aeromonas, Pasteurella, Flavobacterium, Proteus, Arthrobacter, Brevibacterium, Micrococcus, Pediococcus, Lactococcus and Trichococcus, respectively.

In this study, sweet potato meal was chosen as the principal constitute of culture medium to provide carbon source for the growth of yeast (Saccharomyces cerevisiaes). The mutation of original yeast was induced by UV radiation. After primary screening, secondary screening and domestication, a mutant of high alcohol-producing yeast S604 was obtained via 60-s UV radiation and 4-round screening. Then the culture medium composition of the mutant strain was optimized by orthogonal test. The fermntation experiment results showed that the alcohol yield by the mutant cultured in the optimized medium is higher than that by the original strain FCC2129.

Through the determination of mycelial biomass, glucose concentration, pH value and inhibitory rate againgt gastric cancer cells in the fermentation course of Inonotus obliquus, the optimum culture time of 33 d was obtained. Then its fermentation product was made into dried powder after hot water extraction to be used as the raw material of health beverage. The optimal beverage formula was confirmed by orthogonal test and sensory evaluation as follows: Inonotus obliquus powder 0.4%, sugar 3%, lemon acid 0.4% and CMC 0.03%.

Walnut protein was hydrolyzed with alcalase to produce walnut peptide taking degree of hydrolysis (DH) to indicate reaction degree. The results showed that the optimum hydrolysis temperature, pH, substrate concentration, enzyme concentration and time are 55 ℃, 9.0, 8.0%, 6% and 2 h, respectively. Under the above conditions, the DH is up to 76.16%.

The changes of cell morphology of Pseudomonas fluorescens A46, a strain producing 2-keto-D-gluconic acid, were observed by transmission electron microscope after infected by bacteriophage KS461-2. The mutation frequency of P. fluorescens A46 resisting the bacteriophage was determined, the multiplication of the bacteriophage was studied at different pH values, and the control effects of four medicaments on the bacteriophage infection were investigated. The current results showed that the morphology significantly changes following with infection time extending, the mutation frequency of P. fluorescens is about 2.5×10-6, the bacteriophage easily adheres to the host bacteria and proliferates in the pH range of 7.5 to 8.0, and ammonium oxalate can remarkably restrain the multiplication of the bacteriophage and does not affect the growth of P. fluorescens A46, especially the addition of 0.7% is the best.

Glucoamylase and yeast were co-immobilized by adsorption-embedment method with polyvinyl alcohol (PVA)- sodium alginate as embedding materials and with diatomite or activated carbon or alumina as adsorbent. The results showed that the optimum ratio of PVA to sodium alginate is 9:1 and the best adsorbent is diatomite at the addition level of 0.6 g/20 ml. Moreover, the experimental results on the saccharification and fermentation performance of co-immobilized beads indicated that the optimum sorghum powder concentration, fermentation temperature, initial pH value and saccharification-fermentation time are 25%, 30 ℃, 5.0 and 7 d, respectively. Under the above conditions, the alcohol content is up to 11% (V/V). After the coimmobilized beads are continually used for 10 batches, their performances are still stable.

In order to exploit functional food with high efficiency and safety in lowering cholesterol and preventing cardiovascular diseases, the selective medium TPY was adopted to isolate and screen Bifidobacterium from fresh feces of a healthy northeast tiger. The most efficient strain in lowering cholesterol in vitro was administered to artificially induced hyperlipaemia rats by gavage The effects of the strain on serum total cholesterol (TC), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) and body and viscera weights of rats were investigated, and the strain was identified by using VITEK-32 automatic microbe analytic systems. The results showed that 10 strains of Bifidobacterium were isolated and screened out in all, among which strain NO. 4 has the highest activity (57.14%) of lowering cholesterol in vitro. This strain can reduce body weight, serum TC, serum TG, hepatic fat and atherogenic index and enhance HDL-C/ TC value of hyperlipaemia rats. The strain NO.4 is identified to be Bifidobacterium bifidum and has certain utilization value in functional food development.

Through the central combination design of four key factors (ratio of rice to water, koji amount, initial pH and inoculation amount), the sake fermentation process from high-temperature instantaneous gelatinizated rice was investigated. In addition, the indexes of alcohol degree, α-amino acid content, total acid content and residual sugar content were determined, and the prediction model of alcohol degree was set up and optimized by response surface methodology (RSM). The validation experiment indicated that the prediction results by this model are consistent with the actual results. Meanwhile the experiment of feeding fermentation showed that the maintenance of yeast activity may benefit from the feeding. Moreover, the amino acid spectra indicated that the amino-acid concentrations of the obtained sake samples (α0, α1, α2 and α3) are between those of normal sake and rice wine.

Orthogonal tests were designed to optimize the aqueous two-phase extraction process of xylanase from fermentation broth of Aspergillus niger AS3.4039 in this study. The results indicated that the optimum concentrations of PEG 4000, K2HPO4 and NaCl are 19%, 10% and 0 (W/W), respectively. Under these conditions, the separation factor (K) and xylanase yield in top phase (Yt) are 6.23 and 88.67% respectively, and the purification effect is satisfying.

Bacterial strains were isolated and identified from bacteria-fermented lobster sauce samples collected from 10 producing areas in Guizhou province. Through the experiments of pure fermentation, sensory evaluation, determination of protease-producing activity and aerogenesis test, this study aimed to screen non-anaerogenic Bacillus strains that have high protease-producing activity and good flavor and can replace the bacterial strains in spontaneous fermentation of lobster sauce. As a result, 3 strains (BJ3-2, BJ1-3 and ZY4-5) with prominent fermentation quality are screened out from 184 strains of Bacillus, whose protease -producing activities (h/c) are 3.60, 1.71 and 1.50 respectively. The physiological and biochemical identification and the 16S rDNA analysis showed that they belong to Bacillus subtilis. Moreover, the enlarged pure fermentation experiment proved that BJ3-2, BJ1-3 and ZY4-5 may be taken as the reference strains for industrial fermentation

The effects of trypsin treatment conditions, such as trypsin dosage, pH value, treatment temperature and treatment time on beef tenderness were investigated using TA-XT2i texture analyser, and these conditions were optimized through L9(34) orthogonal test. The results indicated that trypsin dosage, pH, treatment temperature and treatment time all have significantly  effects of water holding capacity, water loss rate in cooking and shearing force of beef. The optimum conditions of trypsin-induced tenderization are as follows: 100 U/g beef (0.04%), pH 7.0, 37 ℃ and 1.5 h; or trypsin dosage 150 U/g beef (0.06%), pH 7.0, 20 ℃ and 1.5 h. The significance sequence of these factors is: temperature > trypsin dosage > time > pH.

Tolypocladium sinense was isolated from the fruiting body of a wild Cordyceps sinensis. After growing for 4 to 10 days at 25 to 28 ℃ by shake culture (150 r/min) in a liquid medium (pH 6 to 7) containing glucose 4%, yeast extract 1%, peptone 0.5%, KH2PO4 0.1% and MgSO4 0.05%, the mycelial biomass of Tolypocladium sinense reaches 8.49 to 9.73 g/L. The mycelia extraction rates with petroleum, ethyl acetate, ethanol and hot water are 3.51%, 1.62%, 4.84% and 23.33%, respectively, and the extraction rate of mycelium polysaccharide is 5.31 %. All these extracts of Tolypocladium sinense have scavenging ability, especially mycelium polysaccharide presents the strongest scavenging rates of 49.13% to DPPH·at 2 mg/ml and 82.5% to·OH at 0.08 mg/ml. Moreover, the cytotoxicity of the ethyl acetate extract against leukemia cells such as K562 and SHI-1 line was observed in a MTT assay. The IC50 values on K562 and SHI-1 cell line are 26.55 and 17.75μg/ml, respectively. However, the ethyl acetate extract has low inhibitory effects against PBMC and mouse bone marrow cells. AO/EB staining and TUNEL test demonstrated that the ethyl acetate extract can induce apoptosis of K562 cells. In conclusion, the extracts of Tolypocladium sinense mycelium are potential anti-oxidant and anti-tumor sources.

Objective: To investigated antioxidant activities of Stropharia rugoso-annulata polysaccharides (SRP) in vivo and in vitro, respectively. Methods: The antioxidant activities of SRP in vitro were evaluated by determining its ability to scavenge free radicals and inhibit erythrocyte hemolysis, MDA generation and mitochondria swelling. In animal test, the oxidant damage model was produced by consecutively injecting D-galactose into the hypoderm of mice for 60 days. At the same time the mice were administered orally with three dosages of SRP (100, 200 and 400 mg/kg·b, respectively), and the levels of SOD and MDA in blood were regularly measured. After mice were sacrificed, their blood and liver samples were collected for assaying the antioxidant indexes. Results: in vitro SRP shows excellent antioxidant activities. The IC50 values of SRP to scavenge superoxide radicals is 132.5 μg/ml, the scavenging rate of 583.1 μg/ml SRP to hydroxyl radicals is 47.44%, the inhibitory rate of 832 μg/ml SRP to erythrocyte homolysis induced by H2O2 is 23.8%, the inhibitory rate of 500 μg/ml SRP to mitochondria swelling induced by Fe2++VC is as good as the control group, and the inhibitory rates of 537 μg/ml SRP to liver MDA generation under autoxidation and induced oxidation conditions are 38% and 40.8% respectively. In the animal test, SRP treatment has no effect on the body weight of model mice, but makes the decreased hemoglobin (Hb) content and liver index in model mice recover to the normal range. Compare with the model group, SRP (200 mg/kg) treatment significantly promotes blood SOD activity on the 20th, 40th, 60th day and reduces blood MDA content on the 40th and 60th day after administering. Moreover, SRP treatment significantly reduces serum and liver MDA contents and promotes activities of serum GPx and TAOC and liver endogenous antioxidant enzymes (total SOD, Cu,Zn-SOD, Mn-SOD, GPx and TAOC) of model mice. Conclusion: SRP possesses excellent antioxidant activities of scavenging free radicals in vitro and D-galactose induced oxidative damage in vivo.

Objective：To investigate the protective effects of Zhenggaofang-Guilinggao (GLG) on liver injury of mice induced by restraint stress. Methods：The liver injury model of mice was established under restraint stress for 18 h. Hepatic function was evaluated through assaying alanine aminotransferase (ALT) activity in plasmabu by Reitman-Frankel method, malondialdehyde (MDA ) content by TBARS method. NO content by Griess chemical method, oxygen radical absorbance capacity (ORAC) using enzyme-mark instrument, glutathione (GSH) level by HPLC method, and hepatic glutathione peroxidase (GPX) and glutathione S-transferase (GST) activities by colorimetric method. Results: Compared with the control group of restraint stress, GLG can significantly decrease the ALT activity and the contents of MDA and NO, and increase the levels of ORAC and GSH, the acticities of GPX and GST in liver. Conclusion: GLG has protective effects on liver injury in mice loaded with restraint stress, and the effect may be related to its ability of releasing the level of oxidative stress in mice.

In this study, two ways was used to prove and explain the hypoglycemic function of polysaccharides from Lycium ruthenicum Murr. fruit, among which, one way was to preventively administer the normal mice by gavage with the low, middle or high dosages of the polysaccharides for 11 d, and then intraperitoneally inject the prevented mice with alloxan, and another way was to intraperitoneally inject the normal mice with alloxan to establish diabetic models, and then intraperitoneally administer the diabetic mice by gavage with the low, middle or high dosages of the polysaecharides for 21 d. Finally the hepatin in liver, SOD activity and MDA content in serum and liver, and fasting blood glucose level were determined for the control group, diabetic model group, all treatment groups and metformin hydrochloride group. The results showed that the polysaccharides significantly can reduce glucose level in blood and MDA content in blood and liver, and enhance SOD activity in blood and liver and promote conversion of blood glucose into liver glycogen of diabetic mice. In conclusion, the polysaccharides from Lycium ruthenicum Murr. fruit has prevention and therapeutic effects on hyperglycemia, and can effectively enhance the anti-oxidation ability in diabetic mice induced by alloxan.

Almond protein was respectively hydrolyzed with Protamex, Alcalase, Neutrase, Flavourzyme, Proleather FG-F and Papain, and then the angiotensin I-converting enzyme (ACE) inhibitories activities of obtained hydrolysates were detected by high performance liquid chromatography (HPLC). With the degree of hydrolysis (DH) and the ACE-inhibitory activity of hydrolysate as evaluation indexes, the hydrolysis course and the digestion stability in vitro of the hydrolysate were studied. The results indicated that Proleather FG-F and Alcalase have better hydrolysis ability to almond protein than other proteases, and the IC50 values of their hydrolysates to ACE are 1.24 mg/ml and 0.98 mg/ml, respectively. Moreover, after simulated gastrointestinal digestion their hydrolysates still have high ACE-inhibitory activity.

In this study, 30 male Wistar rats were randomly divided into the control group (n=10) which was fed basic diet, and the model group (n=20) which was fed high fat diet. After 6 weeks, the model group was randomly divided into 2 subgroups: insulin resistant group (n=10) which continued to receive high fat diet, and Phyllanthus emblica L. extract group (n=10) which was fed high fat diet and administered by gavage with 3.5 g/kg body weight of Phyllanthus emblica L. extract at the same time. After the treatment with Phyllanthus emblica L. extract for 6 weeks, the expression levels of PPARγ in the fat tissue of rats were determined by RT-PCR. The results showed that the high fat diet successfully induces insulin resistance of rats, but the Phyllanthus emblica L. extract significantly improves their insulin resistance. The PPARγ expression of rats in insulin resistance group is slightly higher than that of ratsin the control group, but is significantly lower than that of ratin Phyllanthus emblica L. extract group. In conclusion, the Phyllanthus emblica L. extract can significantly improve insulin resistance, which may be related to the increase of PPARγ mRNA expression.

Wheat bran peptides were prepared by alkaline protease (Alcalase) hydrolysis and then purified with Sephadex G- 25 and DEAE-32 column chromatography. The cellulose acetate electrophoresis was used to determine the purity of wheat bran peptide with antioxidant activity. The surperoxide anion radical and hydroxyl radical scavenging activities of wheat bran peptide were detected through nitroblue tetrazolium (NBT) test and deoxyribose method. The erythrocatalysis extent and swelling extent of liver mitochondria were detected using spectrophotometric method. The results showed that the surperoxide anion radical and hydroxyl radical scavenging activities of purified wheat bran peptide are 53.16% and 62.39%, respectively, and the purified wheat bran antioxidant peptide can inhibit swelling of liver mitochondria and hemolysis of red blood cells, indicating that it has significant antioxidation.

The aim of this study was to investigate effects of extracellular polysaccharides (EPS) produced by lactic acid bacteria (LAB) on immunologic function of mice. 220 mice (half female and half male) were divided into 5 groups randomly and administered with saline solution, low and high doses of pure or crude EPS by gavage for 15 d, respectively. Then the cellular immunity, humoral immunity and phagocytosis of mononuclear macrophage of the mice were determined. Compared with the NS group, EPS significantly improves weights of spleen and thymus gland and phagocytic index to apoptosis, and diminishes serum hemolysis value. Moreover, the high dose of crude EPS significantly enhances degree of foodpad swelling of mice, and the high doses of both of pure and crude EPS improve proliferation of T-lymphocytes (p ＜ 0.05 and p ＜ 0.01, respectively). In conclusion, EPS produced by LAB can effectively improve the immunologic function of mice.

Anthocyanin is a water-soluble pigment existing widely in nature, and has various health functions to human body. This paper reviewed the recent research progress on its distribution in world, its contens in different sources and qualitative and quantitative analysis methods.

Chitosan has many health functions such as decreasing blood cholesterol, lowering blood pressure, anti-infections, controlling arthritis, anti-cancer and so on. However, the water solubility of normal chitosan is very poor, which is usually dissolved with acid solution. Recently researchers found that synthesized chitosan derivatives not only can increase the water solubility of chitosan but also improve the antibacterial activity of chitosan, making it possible to use chitosan as a natural food preservative .

Azo-compound inedible pigments are considered as one kind of carcinogens, thus it is necessary to rapidly detect them in food. This article mainly reviewed the detection of azo-compound pigments such as Sudan I and acid orange by spectrophotometric analysis, chromatography and elecrtochemistry analysis, and expatiated on the application of new technology in detection of Sudan I. It was proposed that celerity, sensitivity, low cost and strong applicability are the main selecting criteria of detection method. Both of stripping and cyclic voltammetries of electrochemistry may rapidly, accurately, qualitatively and quantitatively detect single azo-compound in food, but for coexisted azo-compounds their veracity still need to be further discussed.

Proteome is expressed from genome, which may influenced by environmental and processing conditions, and can be seen as the molecular link between the genome and the functional quality characteristics of meat. Therefore, proteomics is a promising and powerful tool in meat science to explain the molecular mechanisms behind different genetic backgrounds or processing techniques of meat. This review introduced some proteomics techniques and their application in meat quality study.

The global trade of food promotes the risk of food safety existing and spreading in wider geographical field, and increases the harmfulness of food safety to a certain extent. Strengthening the construction of scientific and technological support system is useful to promote the development of China s export trade of food. This article analyzed the components of scientific and technological support system, described its situations in developed countries and our country respectively based on different national conditions, and forecasted its developing prospect in future China.

In this paper, a suitability evaluation system was raised on cold chain logistics of vegetables based on costs and efficiency perspective according to four current cold chain logistics patterns of agricultural products. By questionnaire survey, the suitabilities of the four patterns were analyzed. The results of statistical analysis showed that third-party logistics company pattern is the most suitable one for Chinese cold chain logistics of vegetables.

In this article, the substance basis, fuction evaluation and application of antioxidant dietary fiber were reviewed, hiping to provide some references for studying it functionality.