Pseudo ternary phase diagram was conducted using water titration method to choose emulsifier EL-35-ethyl butyratewater system to prepare β-carotene liquid crystal, and the microstructures and rheological properties of 4 emulsifier EL-35-ethyl butyrate-water systems (A1, A2, A3 and A4) with different water masses (the mass ratio of emulsifier EL-35 to ethyl butyrate were fixed at 5:5) were characterized with polarizing microscopy and rheometer. Effects of external conditions, including pH value, preservative (sodium benzoate), saturated ethyl butyrate solution of β-carotene and water amount on stability of this system were discussed. Furthermore, effects of sunlight and pH on the stability of β-carotene were compared in different multiphase systems, including liquid crystal, microemulsion and ethyl butyrate solution. Results revealed that the optimal mass ratio of EL- 35 to ethyl butyrate to water was 1:1:1, and other three external conditions had little effects on the stability of emulsifier EL-35- ethyl butyrate-water system. β-carotene contained in liquid crystal was sensitive, but more stable to light at 25 ℃ than that in ethyl butyrate solution and in microemulsion. pH value exhibited marked effects on the stability of the latter two, but little effect on that of the former. Therefore, liquid crystal presents a convenient and nontoxic vehicle for β-carotene in food industry.

The main objective of this study was to investigate the alterations on chemical structure of whey protein isolate (WPI) and β-lactoglobulin (β-Lg) subjected to the hydroxyl radical oxidation systems induced by 0.1 or 1 mmol/L ferric chloride-0.1 mmol/L ascorbic acid-1 mmol/L hydrogen peroxide system. The contents of total sulfhydryl groups and free amines in both proteins decreased when exposed to the above two hydroxyl radical oxidation systems for 1, 5, and 12 h, while the contents of carbonyl and bityrosine as well as the hydrophobicity increased. The contents of sulfhydryl groups in oxidized WPI and β-Lg decreased by 38.5% and 11.6%, repectively. after 1 h oxidation at low ferric chloride concentration, while the decreases in free amines were 20.68% and 0.64%, separately. Oxidation at high ferric chloride concentration for 5 h led to the elevations in carbony and bityrosinel contents and hydrophobicity in WPI by 32.4%, 132.4% and 16.1%, while for β-lactoglobulin, 8.4%, 28% and 0.7%, respectively. Oxidation induced by high ferric chloride concentration was more pronounced than that by low concentration. The results suggested that the oxidation alters the chemical structure of whey protein isolate and β-lactoglobulin and this effect is ferric chloride concentration-dependent (p < 0.05). β-Lactoglobulin demonstrates a better stability than whey protein isolate.

Anthocyanins were extracted from litchi fruit pericarp with first 60% enthanol and then ethyl acetate, and were purified with macroporous resin XAD-7HP and Sephadex LH-20 in turn. HPLC analysis showed that cyanidin-3-o-rutinoside was main component in the purified anthocyanins containing less flavonol. Total antioxidant capability and scavenging activities to hydroxyl radical, DPPH and superoxide anion of the anthocyanins were determined. Results showed that the anthocyanins had excellent antioxidant activities, and the IC50s to hydroxyl radical, DPPH radical, and superoxide anion radical were 0.69, 1.31, and 1.78 mg/L, respectively.

Objective: The extraction and separation conditions of cerebrosides from sea cucumbers were investigated. Methods：The objective substances were extracted with mixture of chloroform and methanol, primarily isolated with petroleum ether and ethyl acetate, further isolated by silica gel column chromatography, purified by HPLC, and structurally identified by GC-MS. Results: Cerebrosides were successfully extracted and purified from sea cucumbers.

Gelatinization characteristics of lotus root starch were studied using X-ray diffractometer and dynamic rheometer. Alterations in swelling properties, blue value, enzyme hydrolyzability and crystal properties of lotus root starch paste were analyzed during gelatinization. Swelling of starch granule and crystal melting were observed as well as the release of amylose during gelatinization. A multiphase system was formed through gelatinization of starch in the presence of excessive water in which amylose functioned as continuous phase and amylopectin as dispersed phase.

Effects of primary lipid oxidation products of aliphatic aldehydes on volatile sulfur-containing compounds in Maillard reaction system consisting of L-cysteine and D-glucose were investigated. The reaction system containing L-cysteine and Dglucose reacted at 140 ℃ for 1 h and 29 kinds of sulfur-containing volatile compounds were identified by GC-MS analysis including 13 kinds of thiophenes, 7 kinds of thiazoles and 9 kinds of thiols and sulfides. Thiophenes represent the majority of volatile compounds and two new kinds of 2-alkyl thiazolidines and long chain aliphatic thiols were formed in addition of aliphatic aldehyde to reaction system. Significant reductions were found in the concentrations of sulfur-containing volatile compounds in the original reaction system while the contents of 4-hydroxy-2,5-dimethyl-3(2H)-thiophenone flavoring roast and caramel increased. The total amount of thiophenes decreased slightly and thiazoles increased. No changes in the amount of thiols and sulfides were observed. The presence of aliphatic aldedydes had less effect on the total amount of all sulfur-containing volatile compounds.

The chemical composition and the isoelectric point (pI) of porcine plasma protein (PPP) were studied and the factors affecting its functional properties were analyzed including temperature, pH and ionic strength. The results showed that PPP contained 62.5% of protein and the isoelectric point was pH 5, at which PPP possessed the minimum of solubility, foaming activity and emulsion stability of porcine plasma protein. However, the foaming stability reached a maximum at this point. Solubility of plasma protein increased with the increasing temperature within the range of 20-70 ℃ and denaturation of PPP was observed when temperature was above 70 ℃. This denaturation was accompanied by the reduction in solubility. The functional properties of porcine plasma protein could be improved by adding certain concentration of NaCl.

Flavour compounds in fresh milk, UHT milk and PEF-treated milk were analysed by solid phase microwave extraction-gas chromatography-mass spectrometry (SPME-GC-MS). Nineteen, seventeen and eighteen volatile components were identified in fresh milk, UHT milk and PEF-treated milk, respectively and acetone was found to be the main constituent in PEF-treated milk. Compared to other two milks, PEF-treatment showed less effect on the contents of flavor compounds accompanied with the formation of less sulfur-containing compounds related to cooking taste.

The hardness and stickiness of compound fruit bar of longan and plum was tested using texture analyzer, and the factors affecting the testing results were explored, including cross-head speed, sample mass (thickness fixed, but length and width varying), material mass ratio, and storage time. For the compound fruit bar composed of half longan and half plum, significant differences in the hardness and stickiness were found between two results tested at the cross-head speed of 3-120 mm/min and at 240-480 mm/min while no pronounced differences were found between two testing results in 3-120 mm/min or 240-480 mm/min．No marked effect of sample mass was seen on the hardness and stickiness for compound fruit bar composed of half longan and half plum, while mass ratio of longan to plum did affect significantly on the hardness and stickiness, and the compound fruit bar composed of half longan and half plum had the best taste. During storage for 45 days at room temperature, the hardness and stickiness had no significant changes.

The N, N′-methylenebisacrylamide cross-linked starch microspheres (CSM) were synthesized from soluble starch in inverse suspension system. Then the starch microspheres and its adsorption behavior to iron (II) were characterized using scan electron microscope (SEM), FT-IR spectroscopy and X-ray diffractometer, and the mechanism of adsorption was also discussed in the present study. The results showed that the adsorption behavior of the starch microspheres to iron (II) ions was adapted to Langmiur adsorption isotherm equation with nice correlations. At room temperature and pH 4.5, the maximum absorption amount of starch microspheres to iron (II) ions was 0.866 mmol/g within 60 min. Meanwhile, the adsorption rate equation was deduced. The crystallinity of microspheres decreased after the absorption to iron (II) ions.

Glycgrrhizauralensis fisch extract, Rosmarinus officinalis extract, tea polyphenol and vitamin E were selected to prepare natural antioxidant compound for edible oil due to their predominant antioxidation contribution to soybean oil. A orthogonal test design was adopted to optimize the formula of the antioxidant compound. According to the range analysis of obtained test results, the contributions of 4 natural antioxidants to antoxidation were ranked in turn as: Rosmarinus officinalis extract > Glycgrrhizauralensis fisch extract > tea polyphenol > vitamin E, and the optimum formula of the natural antioxidant compound was as follows: Rosmarinus officinalis extract 0.08%, tea polyphenol 0.06%, Glycgrrhizauralensis fisch extract 0.08%, and vitamin E 0.01%. The antioxidant capacity of this compound was weaker than that of TBHO but stronger than that of BHA and BHT.

Kelp powder was extracted with 4 different solvents, including distilled water, methanol, n-butanol and ethyl acetate, and orthogonal test design was adopted to optimize the extraction technology, respectively. The primary structures and antibacterial activities of obtained 4 extracts were analyzed by HPLC and filter paper disc diffusion method, respectively. Glucose was identified in he water extract and the ethyl acetate extract, in which fructose was also identified, trehalose was identified in the methanol extract and the n-butanol extract, in which sucrose was also identified by RP-HPLC analysis. All the extracts showed significant higher inhibitory activity against Bacillus subtilis, Escherichia coli, Gaffkya tetragena and Staphylococcus aureus, and their inhibitory effects could be observed markedly at high dilution. Among the four solvent extracts, the ethyl acetate extract presented the strongest sensitivity to Bacillus subtilis.

Composition and contents of fatty acids in steamed pork with rice powder and its precipitated oil were analyzed by gas chromatography at different processing stages. The results showed that the fatty acids in steamed pork and its oil were mainly C16 and C18. Steaming for 60 min resulted in 1.088-fold and 1.110-fold increases in the mass percentage of C14:0 and C18:2,9c,12c, respectively while C16:0 and C16:1, C18:0 and C18:1,9c, and C18:1,11c reduced to 99.6%, 98.6%, and 99.5%, respectively. However, no pronounced changes were found in the relative contents of fatty acids. The percentage of saturated fatty acids in precipitated oil decreased to 62.66% at the steaming time of 60 min compared to 67.58% when steaming for 20 mins while a significant rise in the content of unsaturated fatty acids was noticed from 27.79% to 32.62%. The were no significant changes in C12:0, C14:0, C16: 0, C16:1, C18:1,11c, and C18:2,9c,12c, while C18:0 and C18:1,9c varies significantly during the whole steaming (p < 0.05).

The effects of pH value and concentrations of sodium chloride and calcium chloride on the properties of complex gel system of low-methoxyl pectin and whey protein isolate (WPI) such as gel hardness and water holding capacity (WHC) were investigated. Through response surface analysis, it was found that pH value and concentrations of sodium chloride and calcium chloride significantly affected the molecular structure of WPI and the interaction between protein and polysaccharide. Moreover, the regression equations on response values were obtained and the optimal pH value and concentrations of sodium chloride and calcium chloride for complex gel were confirmed as 6, 0.2 mol/L and 10 mmol/L, respectively. Under this condition, the obtained gel hardness was about 200 g and the WHC was about 75%.

The crude pigments were extracted from rambutan (Nephelium lappaceum L.) fruit pericarp tissues with 80% of acidified ethanol and purified through silica gel column and Amberlite XAD-7 resin column. Factors affecting the stability of purified pigments were investigated including sunlight, temperature, pH value, oxidant, reducer, preservative, citric acid, lactic acid, glucose, sucrose, VC and metal ions. Rambutan pigments showed high similarity to anthocyanins on the absorption spectrum and exhibited a poor stability to sunlight, heat, hydrogen peroxide and sodium sulfite. Color stability was observed under pH 3 and was enhanced by addition of citric acid. However, no significant effect of sodium benzoate was found at low concentration. Lactic acid, glucose, sucrose and VC exhibited no negative effects on the stability while iron (III), iron (II), lead (II) and stannum (II) ions accelerated the degradation of the pigments.

The content changes of chlorophyll, carotenoid, anthocyanin, flavonoid and phenolic compounds were studied during the fruit development of Chaohong and Richuanbaisha peach, meanwhile the correlations between anthocyanins content and contents of other 4 compounds were analyzed. Results indicated that lower chlorophyll and carotenoids contents were found in Chaohong pericarp and tended to declined more quickly while a higher anthocyanins content with sharp increase. However, pigment contents in Chaohong were lower at the early stage of fruit development and increased at the late stage. Flavonoids content showed a decreasing tendency while phenolic compounds showed the same pattern with pigments. A negative correlation was observed between the contents of anthocyanin and other pigments and phenolic compounds with fewer exceptions.

Active substances extracted from Cichorium intybus L. stems with 95% ethanol were subjected to analysis of antimicrobial activities against four species of fungi and four species of bacteria by filter paper disc agar diffusion technique. Results showed that the extract had broad-spectrum antimicrobial activities against fungi and bacteria and the activities increased with the increasing concentration of extract. However, no effects were observed against Bacillus thuringiensis and saprophytic fungus (Rhizopus sp.) The extract possessed lower minimum inhibitory concentrations when compared to commercial antipreservatives, such as sodium benzoate and potassium sorbate. It exhibited high thermal stability and high antimicrobial capacities within a wide range of pH without pH adjustment for food.

HbNO was synthesized from duck blood and sodium nitrite and the factors affecting its stability was investigated including temperature, light and exogenous additives. Massive precipitates in the aqueous HbNO solution were observed when standing at 85 ℃ for 40 minutes and total sedimentation after 40 days. Turbidity was seen rapidly in the addition of copper (II) and silver ions while no significant change with the addition of zinc (II) and iron (III). Ascorbic acid, sucrose and glycerol were found to enhance the stability of HbNO.

Propolis extracts were prepared by extraction with different solvents and were subjected to assay of antifungal activity against Penicillium italicum and determination of components (i.e. total flavonoids and phenols). In addition, the correlation between the inhibitory rate and the contents of total flavonoids and phenols was analyzed. The results showed that among five extracts of propolis with different solvents, both the ethyl acetate extract and the alcohol extract presented the highest inhibitory rate, 100% ± 0%, but the former contained more total flavonoids than the latter did. The correlation coefficient between the inhibitory rate and the content of total flavonoids was higher than that between the inhibitory rate and the content of total phenols. According to these results, we concluded that the ethyl acetate extract has stronger antifungal activity than the alcohol extract do. Subsequently, the antifungal activity of this ethyl acetate extract was further investigated, as well as the effects of pH and temperature on the stability of the antifungal activity. The results showed that the ethyl acetate extract of propolis exhibited strong inhibitory effects against mycelial growth and spore germination of Penicillium italicum in a concentration-dependent manner. After being heated for 30 min at different temperatures of 25 to 100 ℃,the ethyl acetate extract still retained marked inhibitory effect, and no differences were found in heating temperatures. In the range of pH 3.6 to 7.6, the antifungal activity of the ethyl acetate extract firstly increased and reached a maximum at pH 5.2 and then fell down.

Sensitivity of Escherichia coli O157 to surfactin was determined by oxford cup and microdilution methods, and sterilization characteristics of surfactin were investigated in terms of its effect on growth curve of E. coli O157, sterilization rate and sterilization kinetics. Finally sterilization effect of of surfactin on E. coli O157 in fresh milk was studied. Results showed that E. coli O157 was very sensitive to surfactin and the minimal inhibitory concentration (MIC) was 25μg/ml. Surfactin not only presented inhibitory effect against E. coli O157, also could kill the bacterium. After cultivated in the fresh milk added with 2-time MIC of surfactin for 48 h at 37 ℃, no living E. coli O157 was detected. In conclusion, surfactin has promising application prospect due to its excellent sterilization action.

In this experiment, the ultimate compressive resistance, ultimate compressive strength and elastic modulus of silver carp were tested by using RGT2000-10 microcomputer-controlled universal material testing machine, and the force-deformation curve was measured and analyzed. The results showed that the mechanical parameters of tested points in lines along head-tail axis were basically in consistence. This means that, along head-tail axis, the mechanical properties of fish body tissue are basically the same, while the mechanical parameters of tested points in line along back-abdomen axis were obviously fluctuant. This means that, along back-abdomen axis, the mechanical properties of fish body tissue are significantly different.

Using three-factor and three-level completely randomized experiment design, this study analyzed the effects of κ- carrageenan (κCG), konjac gum (KGM) and modified corn starch (MCS) additions on water holding capacity (WHC), hardness and ultrastructure of chicken muscle homogenate. The results showed that both κCG and KGM had extremely significant effects on the WHC and hardness (p ＜ 0.01). MCS had extremely significant effects on the WHC (p ＜ 0.01), but presented significant effect on the hardness (p ＜ 0.05). Both the interactions between κCG and KGM (extremely significant, p ＜ 0.01) and between KGM and MCS (significant, p ＜ 0.05) significantly affected the WHC and the hardness, while the interaction between κCG and MCS only affected the WHC. Moreover, κCG, MCS and muscle protein may form three-dimensional network structure, and MCS played a filling agent in the gel network void, which made the gel system has a good three-dimensional structure and then affected the water holding capacity and hardness of the gel system.

The properties of buckwheat starch prepared in our lab by wet-milling method were investigated and were compared with those of corn starch, potato starch and tapioca starch. The results indicated that there were some differences in solubility, expansibility, anti-enzymolysis, transparency, freezing and thawing stability, gelatin, thermodynamic property and viscosity property. The buckwheat starch, as a new starch resource, has some utilization values and expansive development prospects.

The applicability of empirical solid uptake predictive models was assessed during acoustic/pulsed-vacuum osmodehydration, and the effect of vacuum or ultrasound on solid uptake kinetics was also investigated. Apple cylinders were submerged in a 60% (W/W) syrup under shaking (55 r/min), pulsed vacuum (13 MPa vacuum for 5 min + atmospheric pressure for 5 min + same vacuum for 5 min, then atmospheric pressure), or ultrasound treatment (50/60 Hz) for 3 h. The R2, χ2, RMSE and E values of seven selected models were compared, Two-term model presented the best fitting for solids uptake. The solute diffusivity ranged from 5.72 × 10-11 to 9.25 × 10-11 m2/s. Pulsed vacuum led to the greatest amount of solids gain (3.02%) and the highest diffusivity (9.25 × 10-11 m2/s).

Grape skin was processed into ultrafine powder. The average particle size of grape skin ultrafine powder was determined as 7.8μm and the broken rate of cell wall was calculated as 100%. Several characteristic indexes of the grape skin ultrafine powder and common powders with different particle sizes were compared. The results showed that the smaller grape skin powder particle size, the higher the fluidity, the solubility, the distribution and dissolution of polyphenols. Therefore, the nutritional components in grape skin ultrafine powder can be better absorbed by human body.

Color pigments with radical-scavenging activity can be formed via Maillard reaction (MR). In the present study, four MR systems of xylose-glycine, xylose-alanine, xylose-aspartic acid and glucose-glycine were heated at 30 ℃ and 60 ℃ and their color, absorption spectral characteristics and ABTS (2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)) radical scavenging activity were assessed and compared. Xylose-glycine MR product (MRP) showed characteristic color and strong absorbance at about 570 nm and 630 nm, which was more obvious at 30 ℃ than 60 ℃. Whereas no apparent peak was observed from xylose-alanine, xylose-aspartic acid and glucose-glycine MRPs. All the four MRPs heated at 60 ℃ had higher ABTS radical scavenging activity than those at 30 ℃. The xylose-glycine and xylose-alanine MPRs prepared at both 30 ℃ and 60 ℃ had higher ABTS radical scavenging activity than other two MPRs.

Twenty-four kinds of metal elements in Fen Liquors produced by different water or stored in different containers were quantitatively determined by flame atomic absorption spectrometry (determining Na, K, Ca, Mg, Fe, Zn, Cu, Mn, Ni, Li, Pb, Cd and Cr), graphite furnace atomic absorption spectrometry (determining Mo, Sr, Ba, Co, Ti, Al and Sn) or atomic fluorescence spectrometry (determining Hg, As, Se and Sb), and the effect mechanism of these metal elements on wine quality was primarily investigated. The results indicated that the kind and the content of elements in Fen Liquor were closely related with its production water and stored containers, that is to say, when produced by different water or stored in different containers, the kind and the content of elements in Fen Liquor were different, and the taste and maturation of Fen Liquor were also different. The present study could provide the scientific guidance for the selection of water source and storage containers in Fen Liquor production.

A Maillard reaction was carried out between 1 g of polylysine (PL) produced through fermentation of Streptomyces albus and 9 g of dextran with 40 kD molecular weight. The covalent attachment of PL to dextran was confirmed by SDS-PAGE and the absorbance measurement of Maillard reaction system at 420 nm wavelength was conducted to determine the conjugation progress between the above two materials. Subsequently, the antibacterial activity and emulsifying activity of PL-dextran conjugate were investigated. The results indicated that the PL-dextran conjugate not only had higher emulsifying activity than that of 0.9% dextran or 0.1% PL, but retained the antibacterial activity of PL. Its emulsifying activity reached the maximum at pH 7.0, and did not decrease in the presence of 1.75 mol/L of NaCl.

Essential oil was extracted from leaves of Liquidambar formosana Hance by steam distillation method. Paper disc assay and spread-plate method were used to determine its antimicrobial activity and minimum inhibitory concentration (MIC). Stability of antimicrobial activity of the essential oil to acid, base, heat and ultraviolet ray, as well as its antioxidant activity, were studied. Results showed that the antimicrobial activities of the essential oil from leaves of Liquidambar formosana Hance against five tested microbes were largely different. The essential oil had strong antimicrobial effect against the Gram positive bacteria while weak effect against Gram negative bacteria. The MICs of the essential oil agaginst Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Aspergillus flavus and Penicillium oxalicum were 1.25 %, 0.625 %, 5 %, 2.5 % and 2.5 % respectively. The antimicrobial activities of the essential oil were stable under the conditions of heat and ultraviolet ray, but were unstable under different pH values, strong in acid and weak in base. The essential oil had good antioxidant activity: the higher the concentration of essential oil, the stronger the antioxidant effect.

Objective: To optimize the preparation technology of ACE inhibitory peptide from WPC-80 whey protein concentrate hydrolyzed by the proteases produced by Lactobacillus helveticus using response surface methodology. Methods: Through single- factor test and response surface methodology, the effects of five enzymatic hydrolysis conditions including temperature, pH, enzyme to substrate ([E]/[S]) ratio, substrate concentration and time on the degree of hydrolysis (DH) of WPC-80 whey protein concentrate and the ACE inhibitory activity were investigated. Results: All of five factors affected the production of ACE inhibitory peptide, and among them temperature, pH and [E]/[S] ratio were the key factors. The optimum temperature, pH, [E]/[S] ratio, substrate concentration and time were 38.90 ℃, 9.18, 0.6%, 6% and 8.0 h, respectively. Under these conditions, the ACE inhibitory activity was 92.21%, its IC50 was 0.375mg/ml, and the DH was 18.76%. Conclusion: The response surface methodology is feasible to optimize the enzymatic hydrolysis conditions for ACE inhibitory peptide preparation.

Mycobacterium B696 can effectively degrade soybean sterol to androst-4-diene-17-dione (4-AD) in oil-water twophase system, but how to enhance the extraction rate and purity of 4-AD is still a problem at present. In the present study, the effects of different pretreatments, extraction ways and crystallization on the extraction rate were investigated. The results showed that the optimal extraction technology was as follows: after 10 min of heat treatment at 50 ℃, extracting the oil phase with 3 times volume of methanol at 15℃, and then conducting the crystallization of 4-AD at 10 ℃ for 15 h. Under these conditions, the extraction yield of 4-AD was 76.61%, and its purity was up to 98.24%.

Based on the experiential data on fermentation in 2.5-L stirred fermentor, several experienced methods were used to study the scale-up of Lactobacillus bulgaricus (KLDS 1.9201) and Streptococcus thermophilus (KLDS 3.0201) batch fermentation from flask production to bench production. The scale-up fermentation of yoghurt strains from 2.5-L to 15-L fermentor could be successfully conducted when the agitation rate ranged from 50 r/min to 80 r/min and the dissolved oxygen concentration was lower than 5%. The maximum lactose consumption and lactic acid concentration for Lactobacillus delbrueckii subsp. Bulgaricus KLDS 1.9201 reached 80.3% and 49 g/L respectively, and the living bacterial number attained 2.2×109 CFU/ml after the growth for 12 h. The maximum lactose utilization and lactic acid concentration for Streptococcus sativarius subsp thermophilus KLDS 3.0201 reached 80.2% and 39 g/L, respectively, and the living bacterial number attained 4.9×109 CFU/ml after the growth for 8 h.

Objective: To study the isolation and purification technology of a broad-spectrum bacteriocin, sakacin produced by Lactobacillus sake G2. Methods: The cell-free fermentation broth of Lactobacillus sake G2 containing sakacin was decolored with active carbon and precipitated with cold ethanol to remove macromolecular impurities, and purified by Sephadex G50 column chromatography and HPLC. Results: The optimum conditions for isolation and purification were as follows: decoloring the cell-free supernatant of Lactobacillus sake G2 with 3.5% of active carbon addition at 40 ℃ for 20 h (the decolorization rate reached 64.5%), finial ethanol concentration 80%, elution flow rate of Sephadex G50 column 0.5 ml/min, sampling volume 3 ml, and taking 90% methanol aqueous solution as mobile phase for HPLC. Under these conditions, the electrophoretic purity of sakacin was obtained. Conclusions: This study can lay the foundation for the future study of physicochemical properties and bacteriostatic mechanism of sakacin.

Casein was hydrolyzed with trypsin to prepare the hydrolysates having immunomodulatory effect. MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] method was applied to assay the stimulation index (SI) of 10 μg /ml solutions (culture liquid 1640) of casein and its hydrolysates at different substrate concentrations and concentration ratios of enzyme to substrate to mouse spleen lymphocytes. The results showed that the SI of the hydrolysate was the biggest, 2.77, which was obtained under the conditions of substrate concentration 4%, concentration ratio of enzyme to substrate 1:90, but casein had no obvious simulation effect on mouse spleen lymphocytes.

An efficient chymosin producing strain, D3.11, was screened out from 18 bacterial strains isolated from the soil of yak grazing district in Tianzhu County of Gansu Province, China, using casein medium, whose chymosin and proteolysis activities were 89.56 SU/ml and 21.27 U/ml after 72 h shaking fermentation (140 r/min) at 37℃ in bran medium, respectively. This strain was identified as Bacillus licheniformis by the means of bacterial morphological feature observation, physiological and biochemical characteristics measurement and 16S rDNA sequence analysis. Furthermore, the growth and enzyme production curves of this strain were plotted.

Objective: To prepare a complete antigen of chloramphenicol (CAP) with high coupling rate, and optimize the coupling conditions of CAP and bovine serum albumin (BSA) by carbodiimide method. Method: Single-factor tests were designed to optimize three main factors affecting the synthesis such as protein concentration, mole ratio of CAP to BSA and pH in reaction system, and ultraviolet (UV) spectroscopy and TNBS method were employed to determine the coupling rate after the synthesis. Results: The optimum BSA concentration, mole ratio of CAP to BSA and pH were 15 mg/ml, 70:1 and 7.4, respectively. Under these conditions, the coupling rate of CPA antigen was about 15. Conclusion: The complete CPA antigen with high coupling rate can be prepared by carbodiimide method for the preparation of antibody.

Changes in activities of various enzymes in barley malt during drying process were investigated. The results showed that the activities of α-and β -amylases increased firstly and then sharply decreased over the whole drying process of 20 h. The activities of carboxypeptidase and aminopeptidase increased gradually to their maximum values during the earlier drying process (at 5 h and 7.5 h, respectively) and then presented little decreases. POD was steadier than the other oxido-reductases and decreased significantly in half of period of languish, but this change was smaller in period of kilning. However, PPO activity was sensitive to heating with steady decrease in period of languish and was destroyed significantly in period of kilning, which in dried malt was 62% of that in green malt. β-Glucanase showed more resistant to heating, and almost no changes in its activity were observed with drying time extending after reaching the plateau at 2.5 h.

Objective: To optimize the preparation technology of angiotensin I-converting enzyme (ACE) inhibitory peptide from casein by the proteases produced by Lactobacillus helveticus using response surface methodology. Methods: Through singlefactor test, the effects of five enzymatic hydrolysis conditions including substrate concentration, hydrolysis temperature, pH, enzyme to substrate ([E]/[S]) ratio, pretreatment temperature of substrate and hydrolysis time on the total peptide content in the hydrolysate and the ACE inhibitory activity were investigated, and three key factors, including hydrolysis temperature, pH and [E]/[S], were optimized by response surface methodology. Results: The optimum pretreatment temperature of substrate, hydrolysis temperature, pH, [E]/[S] ratio, substrate concentration and hydrolysis time were 90℃, 8.94, 0.92% (W/W), 6% (W/W) and 8 h, respectively. Under these conditions, the ACE inhibitory activity was 92.67%.

With soybean meal and wheat as the raw materials, base soy sauce was produced by low-salt and solid-state fermentation in the pond with spraying-extraction, and then its aroma was enhanced by using Rhizopus sp. esterifying enzyme. Via single-factor test and response surface analysis, the effects of esterifying enzyme amount, esterifying temperature and time on the sensory and physical-chemical quality of the soy sauce were investigated. The results showed that the addition of Rhizopus sp. esterifying enzyme significantly enhanced the volatile ester content, and made the soy sauce mellow and fragrant. The optimized Rhizopus sp. esterifying enzyme amount, esterifying temperature and time were 1.0%, 45 ℃, and 72 h, respectively. Under these conditions, the total volatile ester content was 7.512 mg/100 ml, which was 36.3% higher than that in the base soy sauce.

Actinomyceter strain G-HD-4 was isolated from soil sample collected from Huaqiao flower garden in Quanzhou of Fujian Province, which produced the most melanin compared to other isolated 18 strains. The melanin separated from the fermentation broth of strain G-HD-4 was characterized by ultraviolet-visible (UV-Vis) spectroscopy, infrared (IR) spectroscopy, and scanning electron microscope (SEM). The results revealed that the melanin derived from strain G-HD-4 was similar to standard melanin on the structural basis. Based on the studies of physiological and biochemical characteristics and 16S ribosomal RNA sequence homology, the G-HD-4 strain was confirmed to belong to Streptomyces genus and be similar to Streptomyces capoamus (gene sequence similarity 99%). Finally, it was identified as a species of Streptomyces capoamus by taxonomic and phylogentic analysis.

Actinomyceter strain G-HD-4 was isolated from soil sample collected from Huaqiao flower garden in Quanzhou of Fujian Province, which produced the most melanin compared to other isolated 18 strains. The melanin separated from the fermentation broth of strain G-HD-4 was characterized by ultraviolet-visible (UV-Vis) spectroscopy, infrared (IR) spectroscopy, and scanning electron microscope (SEM). The results revealed that the melanin derived from strain G-HD-4 was similar to standard melanin on the structural basis. Based on the studies of physiological and biochemical characteristics and 16S ribosomal RNA sequence homology, the G-HD-4 strain was confirmed to belong to Streptomyces genus and be similar to Streptomyces capoamus (gene sequence similarity 99%). Finally, it was identified as a species of Streptomyces capoamus by taxonomic and phylogentic analysis.

Oat protein was hydrolyzed by Alcalase, Neutrase, and Protamex individually or jointly and the obtained hydrolysates were further subjected to decolorization with activated carbon YD-303 and purification with macroporous adsorption resin DA201-C II for desalination and Sephadex G-25 column for fractionation. The results showed that the hydrolysates of oat protein by individual Alcalase had the highest ACE inhibitory activity of 85.40%. The optimum decolorization conditions with YD-303 contained quantity of activated carbon 1.5%, pH 3.5, 40 ℃, and adsorption time 75 min. Fractions eluted with 75% ethanol from macroporous adsorption resin displayed the highest inhibitory activity and were further separated by Sephadex G-25 into 4 subfractions. The fourth subfraction presented the most effective elution and its inhibitory activity was 95.6%.

Porcine pancreatic residue, remaining after the extraction of insulin, was subjected to primary chemical component analysis and hydrolysis by papain. The results showed that the residues contained fat of 7.15%, water of 32.20%, protein of 50.49%, and ash of 5.58%. The optimal conditions of hydrolysis were as follows: after high temperature treatment for 20 min, with the ratio of solid to liquid of 0.6 and papain amount of 0.6%, hydrolysis at 55 ℃ for 8 h. Under this condition, the degree of hydrolysis was up to 41.25%.

Escherichia coli is generally used as the health-indicator bacterium in microorganism detection of bottled water. However, when induced by low temperature or Cu2 +, Escherichia coli can enter the viable but non-culturable state and not be detected by the general detecting culture medium. Staphylococcus aureus, a gram-positive pathogenic bacterium, is also found the existence of viable but non-culturable state. Therefore, these bacteria in this state will be escaped only using the present microorganism detecting way. In the resuscitation experiment of the present study, it was found that catalase and Tween 20 could excite the culturable ability of the two species of bacteria from the viable but non-culturable state in a short time.

The objective of this study was to construct a rpoH gene deficiency variant strain of Salmonella enteritidis IFO3313 called IFO3313-Δ rpoH and characterize the heat shock response of wild type and mutant strains under different temperatures. The kanamycin-resistant DNA cassette with 39 bp short homologous sequences on both ends generated by PCR was electroporated into Salmonella enteritidis IFO3313. Recombination between linear DNA cassettes and Salmonella enteritidis chromosomes took place with the help of λ-Red recombinase system and was confirmed by PCR method. Based on this, the heat shock response and the repair of sub-lethal heat injured wild type and mutant strains were compared using different media at different temperature. The wild type strain presented stronger heat-resistance and repair capacity in tryptic soy yeast agar (TSYA), compared to the mutant. False-negative results from the detection of the sub-lethal heat injured Salmonella enteritidis could occur in the desoxycholate–hydrogen sulfite–lactose agar (DHL). The rpoH gene knockout in Salmonella enteritidis using λ-Red recombination system provides us better understanding to the mechanism of heat shock and repair of Salmonella enteritidis.

Exo-inulinase and endo-inulinase from Aspergillus ficuum were subject to chemical modification of seven protein modification reagents and to identification of amino acid residues essential for enzyme activity. The results suggested that Nbromosuccinimide (NBS), carbodiimide (EDC) and diethyl pyrocarbonate (DEPC) resulted in a great loss of endo- and exoinulinase activities, indicating that Trp, carboxyl amino acid (Glu or Asp) and His residues may be parts of the enzyme active sites, respectively. Two Trp residues essential for exo-inulinase active site and one for endo-inulinase were confirmed by Tsou’s method.

A total of 71 strains of yeast were isolated from pomegranate leaves and rind as well as pomegranate garden soil. After 3 screening cycles, 2 strains, numbered as SL18 and SL20, were obtained, which were the most suitable for production of pomegranate wine. According to morphological observation and physiological and biochemical tests, the 2 strains were identified as Saccharomyces cerevisiae. In addition, the fermentation performances of this 2 strains and active dry yeast (Anqi brand) were compared. Results showed that when the fermentation temperature was 25 ℃, the fermentation cycle of strain SL20 was 1 day shorter than that of strain SL18 and active dry yeast, the alcohol degree was up to 9.7% (V/V) at the end of fermentation, and the wine product obtained was full-bodied and sterling. Although the fermentation cycle of strain SL18 was the same as that of active dry yeast, the wine produced by the former was more full-bodied and sterling than that produced by the latter. When the fermentation temperature was 30 ℃, all the three starters led to rapid fermentation at the early stage, the fermentation cycle of both strain SL18 and SL20 was 1 day shorter than that of active dry yeast, and the alcohol degree produced by strain SL20 was higher than that produced by strain SL18 and active dry yeast, reaching 10.1% (V/V), but for these three starters, the flavors of pomegranate wines produced by them was not more full-bodied than those produced by them when the fermentation temperatures were 20 and 25 ℃, indicating that strain SL18 and SL18 are more adapted to 25 ℃ fermentation and can endure alcohol degree of 12% (V/V), and the quality of the wine products produced by them is superior to that produced by active dry yeast.

With monoamine oxidase (MAO) as the target, the inhibitories activities of the methanol-ethyl acetate (1:1, V/V) extracts from the broth and mycelia of Paecilomyces cicadae RCEF0947 were investigated. It was found that the broth extract had good inhibitory activity against MAO-A, and the IC50 was 272.97 μg/ml; while for MAO-B, when the reaction concentration of sample was 400 mg/ml, both the extracts from broth and mycelia of RCEF0947 showed strong inhibitory activity with the IC50 of 538.37μg/ml and 509.36 μg/ml (no significant difference between them, p > 0.05), respectively. Meanwhile, a Resazurin cytotoxity assay model of Chinese hamster ovary cells (CHO) was employed to study the anti-tumor activity of extracts from the strain RCEF0947. The results revealed that both the extracts from broth and mycelia of RCEF0947 had strong anti-tumor activity with IC50 of 122.35μg/ml and 171.93μg/ml, respectively.

A total of 40 Kunming mice were randomly divided into 4 groups (group A, group B, group C and group D), with half male and half female. Group A as the control was subject to oral administration and then intraperitoneal injection of normal saline. Group B as the oxidative damage model, group C and group D all were subject to intraperitoneal injection of cyclophosphamide and then oral administration of normal saline, and low dose and high dose of squid ink extract, respectively. The organ index of spleen, content of MDA and the activities of SOD, CAT and GSH-Px in spleen tissue were determined, and the quantity of leukocytes in peripheral blood was counted. Compared to the control group, cyclophosphamide was able to decrease the organ indexes of spleen (p ＜ 0.05), as well as the SOD, CAT and GSH-PX activities (p ＜ 0.01) and increase MDA level in spleen tissue. Compared to the oxidative damage model group, high and low doses of squid ink extract could improve the above oxidative damage symptoms at different degrees, but the therapeutic effect of the former was not more apparent than that of the latter was. In conclusion, sepia ink extract at the suitable concentration is able to alleviate the in vivo immunosuppression induced by cyclophosphamide in mice.

Proanthocyaidins were extracted from lotus seedpod (LSPC) and lotus seed hulls (LSHPC) with 1% NaHSO3 solution by boiling for 15 min and purified with AB-8 macroporous resin. After incubated with culture medium containing different concentrations of the proanthocyaidins from LSPC and LSHPC for 48 h and 72 h, the viability of mouse melanoma B16 cells was measured by MTT assay, and their morphology was observed under inverted microscope and fluorescence microscope after 72 h incubation with medium containing the two proanthocyaidins at 100μg/ml. The in vivo inhibitory effect against the proliferation of mouse melanoma B16 cells was investigated by using C57BL/6J mice, and the levels of superoxide dismutase (SOD) and malonicaldehyde (MDA) in mouse serum were determined by xanthine oxidase assay and thiobarbituric acid assay. Results showed that both the proanthocyaidins from LSPC and LSHPC were able to significantly inhibit proliferation of B16 cells in vitro, and the inhibition rates were 87.4％ and 78.2％, respectively. The morphological alterations of melanoma B16 cell membrane damage caused by them were observed. Both the two proanthocyaidins could significantly reduce the volume and mass increases of melanoma B16 in in vivo experiments, and their inhibition rates at 120 mg/kg bw against the mass of melanoma B16 reached 55.3％ and 46.7％, respectively. Serum MDA level was reduced by administration of the proanthocyaidins from LSPC and LSHPC accompanied with the enhancement in serum SOD activity.

Angiotensin-converting enzyme inhibitory peptides (ACEIP) from jellyfish were prepared via enzymolysis with protease Protamex at pH 6.5 and 50 ℃ for 6 h. Then the anti-hypertensive effects of the ACEIP on narrowed kidney artery caused hypertension and NG-nitro-L-arginine (L-NNA) induced hypertension models in New Zealand white rabbits were studied. The results showed that after 0.5 h of treatment by gavage, the jellyfish ACEIP began to play the antihypertensive effects on both hypertension models. When the dosage was less than 60 mg/kg bw, the anti-hypertensive effect was positively correlative with the dosage. When the dosage was 60 mg/kg bw, the anti-hypertensive effects reached the top, and the increased dosage may not lower the blood pressure below the normal value, but result in longer duration of lowered blood pressure. Compared with commercial anti-hypertensive drugs such as valsartan and benazepril hydrochloride, the jellyfish ACEIP showed the better anti-hypertensive effects against narrowed kidney artery caused hypertension model at the same dosage.

The microwave degradation product, named as PC2, of lambda-carrageenan, was separated into three fractions by DEAE-cellulose DE-52 column chromatography. T-lymphocytes and macrophage obtained from healthy mice were cultured in the presence of the three polysaccharide fractions to evaluate their immunocompetence through cell proliferation, neutral red phagocytosis and nitric oxide(NO) release tests. The results indicated that the contents of sulfate and molecular weights of carrageenan fraction CF1, CF2 and CF3 increased in turn. All these fractions could significantly promote Con A caused spleen T-lymphocyte proliferation and also increase phagocytic activity of mouse peritoneal macrophage and NO release. In conclusion, he degraded lambda-carrageenan is able to enhance the immunity of healthy mice.

Dried pine needles were extracted with 20% of ethanol three times and then the collected extract was concentrated in a rotary evaporator. The effects of the extract concentrate on myocardial free radical metabolism and ultrastructure in mice after exhaustive exercise were investigated. A total of 40 Kunming mice were randomly divided into two groups: sedentary group and exercise group, and each group was further divided into two subgroups orally administered with the pine needle extract and not, respectively. The mice were continuously administered with the extract for 20 days and then subjected to exhaustive swimming. The levels of supersoxide dismutase (SOD), total antioxidant capacity (T-AOC) and malondialdehyde (MDA) in myocardium were measured. Significant elevation in the activities of SOD and T-AOC were found accompanied with the pronounced reduction of MDA content. These data suggested the protection effect of pine needle extract on myocardium from oxidative damage.

The antistress properties of Rhodiola capsule were investigated in Kunming mice exposed to various experimental models of stress. Mice were randomly divided into a control group without administration of Rhodiola solution and two experimental groups once a day administered with Rhodiola solution at the dose of 1.0 g/kg bw and 0.5 g/kg bw by ig route for 30 days. The normobaric hypoxia, cold and heat endurance, hemoglobin (Hb) content of blood and survival time after ip NaNO2 administration were measured. Rhodiola treatments at both the doses were able to provide good protection against stress induced by hypoxia and high or low temperature when compared to the untreated mice. The normobaric hypoxia, cold and heat endurance time, survival time after NaNO2 poisoning were significantly extended and the Hb conctent was markedly higher than that of the control mice.

Antimutagenic and antitumor effects of two kinds of green tea and white tea products were investigated by Ames test and MTT assay, respectively. Ethanolic extract of white tea displayed significantly higher antimutagenicity against Nmethyl- N'-nitro-N-nitrosoguanidine (MNNG)-induced mutation of nutrient deficiency strain TA100 of Salmonella typhimurium than that of green tea at 1.25 mg/disc and 2.5 mg/disc. At the concentration of 400 μg/ml, Baimudan white tea and Baihaoyinzhen white tea showed better inhibitory effects against the growth of AGS and HT-29 cancer cells than Longjing green tea and Yunwu green tea. These results suggest that the antimutagenic and anticancer effects of white tea are higher than those of green tea.

The objective of this study was to investigate the anti-obesity function of kombucha, a traditional fermented tea beverage. With body weight gain, body fat content, serum lipid level, organic indexes, liver and fat organization forms as the indicators, the high-fat induced obese mice were fed for 11 weeks to compare the effects of tea leaching solution (5 g of Yunnan black tea was soaked with boiling water three times, for 10 min each time, and then diluted to 1 L), A4 (Gluconacetobacter sp. A4) broth (fermented 1 L of tea leaching solution containing 80 g of glucose under 10% inoculation amount of strain A4 seed liquid at 30 ℃ for 8 d ), kombucha broth (fermented 1 L of tea leaching solution containing 80 g of sucrose under 20% inoculation amount of kombucha mother liquor at 30 ℃ for 8 d) at the dose of 10 ml/kg bw on the weight control of mice. The results showed that all the three liquids delayed the body weight gain, reduced the body fat content and fat accumulation in the liver, and lowered the course of adipocyte growth. Among them, A4 broth performed the most significant effects on the body weight control of dietinduced obesity mice.

This paper reviewed phosphorylation methods, reaction mechanisms and the effects on functional properties of food protein, and analyzed the research prospect in this field.

Alzheimer’s disease (AD) is one of the most serious threats to human health, especially in aged societies. At present, lifestyle-related factors such as diet and exercise on the prevention and treatment of AD have received increasing attention. A number of in vivo and in vitro studies have shown that dietary intervention possesses an important role in the onset of human AD. In this paper, the recent findings regarding nutrition, including plant polyphenols, vitamins, fatty acids and diet structure, as the possible prevention effect on AD, were discussed.

Meat tenderness would change significantly in thermal process. Generally, with increase of heating temperature, the shear force value increases in the range of 0 to 100 ℃ then decreases at higher temperature, but cooking loss increases gradually with increase of temperature. These changes are caused by heat induced denaturation of meat protein. Myofibrillar protein and connective tissue as two main component of meating protein, their denaturation in thermal process is major factors affecting meat tenderness.

There are lots of unknown and “unculturable” microorganisms in food, but traditional microbiological methods not only are labor-intensive and time-consuming, but may cause deviation. Denaturing gradient gel electrophoresis (DGGE) is a cultural-independent molecular technique, and has been recently introduced into food microbial ecology. DGGE could easily identify the microorganisms from food, avoiding the potential deviation of traditional methods. This review summarized the development, concept, principle, operation procedure of DGGE and its application in food and food-related ecosystems. The limitation and application prospect of this approach in food microbiology were also discussed.

The review introduced the theory of molecular imprinting technique, the process of producing molecularly imprinted polymer (MIP), the indexes for evaluating MIP properties, the MIP preparation of some common mycotoxins in grains such as zearalenone, ochratoxin A, deoxynivalenol and aflatoxin, and the application of mycotxin-MIP in determination of mycotoxin by solid phase extraction and biosensor, and analyzed the prospect and problems to be solved on the application of molecular imprinting technique in determination of mycotoxin.

Melamine is a small polar triazine compound. Due to its rich in nitrogen, it has been added to give a false impression of high protein content. Melamine added to food and animal feeds could possibly cause fatal kidney stones. Determination of melamine is therefore of large importance to ensure food safety. This article reviewed the modern methods of sample preparation and determination of melamine in foods and animal feeds including high-performance liquid chromatography, gas chromatography- mass spectrometry, high-performance liquid chromatography-mass spectrometry and enzyme-linked immunosorbent assay.

Through the statistical analysis of publication time, source, author, address, subject and citation of Science Citation Index (SCI)-embodied literatures, the developing actuality of food science and technology in China was discussed. Results showed that total 2735 literatures on food science and technology in China were embodied by SCI during 2000—2007. Among them 1571 literatures, which occupied more than 50%, were published on the top 10 journals in nearly 100 searched ones, indicating that these published articles were at a high level as a whole. Moreover, these published literatures were mainly from the universities and the research fields focused on food chemistry and agricultural sciences.

Antibacterial peptides widely distribute in the bodies of bacteria, virus, animals and plants, and are an important component in the natural defense of most living organisms against invading pathogens. Following with more and more generation of drug-resistant strains today, the research on antibacterial peptide attracts more and more interests of scholars at home and abroad. This review summarized antibacterial peptides prepared by hydrolyzed food-derived protein in the following aspects: preparing antibacterial peptides from milk protein and non-milk protein by enzymatic hydrolysis, improving antibacterial activity of food-derived protein via proteolysis, selecting appropriate enzyme and enzymatic conditions, purposely modifying antibacterial products, and prospected future research focus on antibacterial peptides from food-derived protein by proteolysis.

Because of their high efficacy and low cost, aminoglycosides have become one of the most universal antibiotics in the world and are widely used in breeding industry. However, their application has been limited in most countries due to their ototoxicity and nephrotoxicity. This paper introduced the detection techniques of aminoglycoside residues in animal products, especially immunologic analysis and multi-residue analysis.

China has established food recall system legally. Based on the practice related to food recall system at home and abroad, this paper started from the design concept of food recall system and tried to make a re-understanding about how to design China food recall system theoretically and make it play a due role practically.