Objective: The aims of this study were to investigate mathematical relationships of pork tenderness with muscle fibre diameter, density and intramuscular fatty area (IFA). Method: Six varieties of cross-bred pigs (N=36) were taken as study objects, and meat or muscle samples were all from M. longissimus dorsi (ld, n=36×2 or ×3) and M. psoas major (pm, n=36 × 2 or × 3), respectively. Two-dimensional microscopy images of histomorphology characteristics of skeletal muscle were reconstruted, and mathematical relationships of pork tenderness with histomorphology characteristics were fitted. Results: The muscle fibre diameter and density in pm are thinner and denser than those in ld. However, the IFA in pm is less than that in ld. The muscle fibre diameter is the most significant factor affecting the pork tenderness with the linear coefficient (r) of 0.966 (p <0.01). It means that the thicker the muscle fibre is, the worse the pork tenderness is. Otherwise, the muscle fibre density varies with its diameter. The muscle fibre density decreases, when its diameter increases. So the linear relationship between the muscle fibre density and pork tenderness is significantly negative (r=0.905, p<0.05). The tenderer the muscle fibre is, the denser the muscle fibre is. But, the effect of muscle fibre density on pork tenderness is less than muscle fibre diameter. In this study, IFA is only about 3% of total muscle area, so it is not enough to carry weight on pork tenderness. Conclusion: Muscle fibre diameter and density have remarkable effect on muscle tenderness, whereas IFA mostly affects the smack but not tenderness. In five vatieties of Shennong, their muscle fibre is thinner with the better pork quality (tenderness) because these pigs are bred from Taihu swine.

Request for the mechanical properties of natural casing in various cases is different. Some of mechanical properties of natural casings could be changed with the application of ultrahigh pressure in casing process. In this study, the shearing strength and tensile strength of natural hog casing under 100 to 600 MPa, at 20 to 45 ℃ and 5 to 30 min pressure-holding time were investigated by using single factor test method. The results showed that the shearing strength and tensile strength of pressurized casing are markedly enhanced under 300 to 600 MPa at 20℃ (p ＜ 0.05). However, both of the strengths are decreased obviously under 300 MPa at 45℃ (p ＜ 0.05). The effect of pressure on them is barely marked during 5 to 30 min under 300 MPa, and 20℃ (p＞0.05). In conlusion, the decrease of both of the strengths in pressurized casing is beneficial to improve the texture properties of casings and the increase of tensile strength is also advantageous to enhance the possibility of applying casing to tissue engineering.

Objective: To optimize process conditions of separation and purification of total flavonoids from Lycium ruthenicum Murr. with macroreticular resin. Methods: Siginal factor and orthogonal tests were done. Results: Using AB-8 resin to adsorb and purify total flavonoids from Lycium ruthenicum Murr, the optimal purification conditions are as follows: concentration of sample solution 0.200 mg/ml,velocity of sample solution 2 ml/min, pH 5, velocity of 95% ethanol taken as eluent 4 ml/min, and volume of 95% ethanol 5 BV (bed volume). The saturated adsorption capacity of AB-8 is 0.64691 mg/g resin, and after used 9 times repeatedly, adsorption capacity of AB-8 is still good. With these paramaters, the purity of product is 28.0%. Conclusion: AB-8 resin is effective in the adsorption and purification of the total flavonoids form Lycium ruthenicum Murr. with good repetition and stability. Therefore, the above technice is suitable to industrial production.

By means of periodate oxidation , Smith degradation , methylation, GC, GC-MS, the structure of low molecular weight polysaccharide, LWPP-Ia isolated from pumpkin was analyzed. Monosaccharide composition analysis of LWPP-Ia indicated hat it is a low branched molecule composed of glucose, fructose and galactose in the molar ratio of 3.6:1:1.2. The main chain is made up of (1 → 4)-linked-Glu and (1 → 4)-linked-Gal1 Some of (1 → 4)-linked-Glus were substituted at 2-O. The (1 → 2)- linked Glu is on the position 1 of side chain and the branch end is (1→)-Glu and (2→)- Fru.

Essential oil was extracted from Cuminum cyminum L. fruit with steam distillation extraction method in 2.6% yield. The chemical components of the essential oil were analyzed with gas chromatography-mass (GC-MS). Twenty-eight components were detected and twenty-six components among them (99.801% of the total essential oil) were identified. Cuminal (39.511%) is the main component, followed by 2-caren-10-al (17.707%) and 3-caren-10-al (17.542%). The sodium nitrite scavenging effect of the essential oil was studied. It was found that the essential oil has considerable sodium nitrite scavenging effect with the maximum scavenging rate 92.5%. The extracts from residue after steam distillation extraction with different organic solvents also show significant sodium nitrite scavenging effects, and the maximum scavenging rates of acetone, methanol and ethanol extracts are 71.1%, 58.7% and 45.5%, respectively.

Starch graft copolymer microspheres were synthesized by inverse suspension polymerization with N,N'- methylenebisacrylamide and soluble starch, using K2S2O8-NaHSO3 as initiator. The adsorption behavior of starch graft copolymer microspheres to Cd2+ was investigated. The starch graft copolymer microspheres and their adsorption products were characterized with scan electron microscope (SEM), FT-IR spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that the adsorption behavior of the copolymer microspheres to Cd2+ is adapted to Langmiur and Freundlich adsorption isotherm equation. Furthermore, the adsorption of Cd2+ on microspheres not only decreases their crystallinity but promotes the rupture of bonds among their main chains.

Newhall navel orange [Citrus sinenisis (L.) Newhall] fruit was used to study the changes of flavonoids and antioxidant activity and the relationship between them during its growth. The results showed that flavonoids content, antioxidant activity in vitro, H2O2 -scavenging capacity and O2·-scavenging capacity in peel decrease during the fruit growth. But the changes of all these parameters in pulp display single-peak patterns and most peaks are found on 15th of September. According to correlation analysis, there is a significant positive relationship between flavonoid content and antioxidant activity or H2O2 -scavenging capacity or O2·-scavenging capacity, and their correlation coefficients are 0.9664 (p＜0.01), 0.7723 (p＜0.01) and 0.9144 (p＜0.01), respectively.

The antimicrobial effects of different extracts from Pinus massoniana Lamb, Pinus elliottii Engelm, Pinus thunbergii Parl with different solvents were investigated respetively. Result showed that all the pine needle crude extracts inhibit the growth of Escherichia coli, Bacillus subtilis, Staphylococcus aureus,Saccharorngces cerevisiae, Penicillium sp. and Aspergillus in different degrees. Especially, they have remarkable antimicrobial effects on Bacillus subtilis and Aspergillus. Furthermore, the antimicrobial activities of water and enthanol extracts of these three cultivars of pine needles have wider pH range (5 to 9).

In this study, barley malts were processed by complete experiment, considering the eddects of initial languish temperature and kilning temperature on malt quality. It was found that β-Glucanase activity in dried malt has significant positive relationship (p＜0.01) with α-amylase activity, proteinase activity, extract yield, α-N or Kolbach Index, but it has significant negative (p＜0.01) relationship with saccharification time, wort viscosity or content of β-glucan. With β-glucanase activity increasing, the wort viscosity reduces but the content of β-glucan inreases and qualities of malts are improved. Both of the initial languish temperature and kilning temperature have effects on β-glucanase activity, but kilning temperature is more significant than initial languish temperature. The highest β-glucanase activity in dried malt is obtained when initial languish temperature is controlled at 48℃, and kilning temperature is controlled at 78℃.

The antioxidant activities of ethanol or water extracts from eleven species of natural plants were measured with DPPH (2,2-dipheny1-1-picrylhydrazyl) method, respectively. The results indicated that all of them have antioxidant activities， especially some flavonoids-rich extracts, which show stronger antioxidant activities with dose-effect relationship. Furthermore, the antioxidant activities of bee pollen and propolis extracts are the strongest among all the extract samples.

The SCF-CO2 extraction process and GC analysis of fatty acid of “Xiaobai” apricot almond oil were investigated in this study. The results showed that the parameters for extracting apricot almond oil with SCF-CO2 are determied as following: extraction press 30 MPa, temperature 35 ℃, extraction time3.0 h, CO2 flow rate 15 to 20 kg/h, and using absolute C2H5OH as cosolvent with amount of 10% (accounting for the total raw material). “Xiaobai” apricot almond oil is rich in unsaturated fatty acids, especially oleic acid and linoleic acid，accounting for 91.65% and 91.75%, respectively.

Effect of ultra-high pressure sterilization technology on the qualities of fresh raw milk was studied. Fresh raw milk was subjected to UHP treatment (continuous, alternative pressure treatment and hurdle technology) at selected pressure (350 to 600 MPa) for various holding times. Pressure treated samples were enumerated to determine the residual microbial population and initial counts were obtained from the control samples. The changes of nutrition in milk treated with different technologies are also deterimined. Resilts showed that:(1) Higher pressure, longer holding time and more alternative times favour a larger destruction of microorganisms; (2) The combined effect of barrier (fence) technology and pressure on the destruction of microorganisms in fresh raw milk is more effective than that of only pressure treatment, and the effect of ε -polylysine on inactivation of microorganism in fresh raw milk is more effective than that of Nisin at the same concentration of 100 mg/L; (3) Compared with the SDS-PAGE electrophoretogram of whole proteins in fresh raw milk, the first bands near the negative pole of those in milk treated with different sterilization ways disappear and the colour of the second bands has slight loss, which suggests that subunits of some proteins are dissociated, but the 400 MPa-treated milk shows the similar eletrophoretogram with the fresh raw milk; (4) The loss of threonine, VA and VC in high pressure-treated milk is much less than those in pasteurism-treated milk, in particular threonine and VA are almost retained, and the contents of VB1 and VB2 in the former also more than that in the latter; (5) High pressure-treated milk has longer shelf life than pasteurism-treated milk, extending the sale semidiameter of products.

Effects of height of chicken sauage sample and degree of compression on TPA results were investigated. The results indicated that height of sample has little effects on hardness and resilience, but has significant effects on cohesiveness and springiness；However the degree of compression has extremely significant effects on hardness, cohesiveness and resilience, expect significant effect on springiness. Quadratic models were fitted for resilience and cohesiveness, which had statistical significance. It was found that hardness increases basically linearly with testing rate, cohesiveness shows little change, and chewiness and springiness have extremely similar change tendency. Meanwhile, TPA test conditions were chosen primarily, and the ideal conditions were estimated, including height of sample (2.0 cm), degree of compression (70%), and test rate (2 mm/s).

The production of Douchi, a Chinese traditional fermented soybean product, was replicated in the laboratory on a small scale in order to study the biochemical changes associated with the ripening process. Douchi was made by mucor SP. fermenting uncracked, undehulled and cooked soybean seeds and followed by a 42-d ripening at 45 to 48 ℃. Changes in proximate compositions (moisture, ash, crude lipid, dietary fiber, carbohydrate and energy), total nitrogen, non-protein nitrogen, nitrogen soluble index, amino nitrogen, water soluble nitrogen, free amino acid concentration, in vitro digestibility of protein, total titratable acid, and browning index of Douchi with different length of ripening time were analyzed. Results showed that ash content increases over the ripening process, while dietary fiber and carbohydrate significantly diminish. A sharp increase and a slight decline in total titratable acid are detected at the beginning (0 to 8 d) and end (32 to 42 d) of ripening, respectively. Total nitrogen keeps stable, while non-protein nitrogen, nitrogen soluble index, amino nitrogen, water-soluble nitrogen, free amino acid concentration, and in vitro digestibility of protein increase throughout the ripening process, which results in enhancemant of nutritional value of product.

The extraction of Sapium sebiferum Roxb epidermis oil was carried out with supercritical fluid carbon dioxide technique, and the effects of extraction pressure, temperature and CO2 flow rate on extraction rate of Sapium sebiferum Roxb epidermis oil were investigated through orthogonal design．The results showed that the optimal extraction pressure, temperature, CO2 flow rate and time for the maximum extraction rate are 40 MPa, 36 ℃, 20 L/h and 1 h, respectively. Meanwhile the components of Sapium sebiferum Roxb epidermis oil were analyzed with gas chromatography (GC).

The fruit quality and juice-making suitability of there different guava (Psidium guajava L．) cultivars were evaluated, and their sugar and acid compositions and antioxidant activities were analyzed. The results showed that“Zhenzhu”has the highest content of total soluble solids (TSS) (9.11%) and its titratable acids is also high (0.36 g/100 ml); “Xinshiji” has the highest contents of VC (4.96 g/L), total phenolics (2.13 g/L) and TAC (67.26 mmol/L). A comprehensive evaluation showed that “Xinshiji” scores the highest in fruit quality, while “Zhenzhu” scores the highest in juice-making suitability. Fructose, glucose and sucrose are the predominant sugars in guava. The three guava cultivars are all monosaccharide-prevalent, with higher fructose content. Different cultivars contain different acid compositions. The main acids in“ Xinshiji” are citric acid, succinic acid and propionic acid, while those in“ Zhenzhu” and“ Shuijing” are citric acid, succinic acid, α-ketoglutaric acid, propionic acid, tartaric acid and pyruvic acid. Among them, citric acid and succinic acid are the two dominant organic acids“. Xinshiji” is the highest in antioxidant activity.

Artichoke is a vegetable rich in active polyphenols (mainly chlorogenic acid). Polyphenolic compositions in different parts of artichoke are different, and they vary with season. The order of polyphenols content is as follows (from most to least): leaf ＞stem＞ flower bud and the older leaves＞ new leaves. Treatments such as high temperature, alkaline condition and damp environment should be avoided, otherwise, the polyphenols, especially chlorogenic acid would be lost. Microwave pretreatment， ethanol immersion and shade drying could reduce the polyphenols losses.

This study focused on citral which is the main component of essential oils such as Litsea cubeba oil and lemongrass oil, and explored a experimental approach of MTT assay in the selection of antitumor essential oils. It compared the effects of different wavelengths on absorbance, taking citral as experimental drug and non-volatile adriamycin (ADM) as control, investigated their volatility and diffusibility according to morphological changes of human K562 cells, and explored the effect of stockage temperature and time on the repetition of MTT assay. It was found that the results followed the same trend at different detection wavelengths as 492 nm, 570 nm and 630 nm. The volatility and diffusibility affect both control and citral treated wells, and make the well that adjoined high concentration well show higher cell toxicity than its actual value. The results also proved the low temperature stockage of volatile essential oils to be not only advisable but also a key point for good experimental repetitions.

To confirm the feasibility of nitrosohemoglobin made from blood for the application to industry, its effect on the quality of red sausage was studied. The results showed that the addition of nitrosohemoglobin significantly increases the a* value of red sausage (p＜0.05) and decreases the value of TBARS. Also, nitrosohemoglobin reduces the residue of sodium nitrite and total plate counts of red sausage. Furthermore, sensory evaluation showed that the optimum addition of nitrosohemoglobin is 0.15%. In conclusion, nitrosohemoglobin plays a role of antioxidant and colorant and could be used to substitute nitrite in the processing of red sausage to improve its sensory quality.

Beaded chitosan resins were prepared, which show good thermostability when temperature is lower than 172 ℃. Tea polyphenols (TP) was separated from green tea via the absorption of the beaded chitosan resins. The conditions and the mechanism of adsorption and desorption of TP were discussed. The results showed that the optimum adsorption conditions of TP (1.573 mg/ ml) in 25 ml tea soup are as follows: the beaded chitosan resin 4.0 g ( dry weight 0.22 g ), adsorption time 2 h, pH of tea soup 7.06 and adsorption temperature 30 ℃. The extraction rate can reach 74.1% under the above conditions and the absorption capacity is 136.1 mg/g. Furthermore, the experimental results showed that the adsorption kinetics of the beaded chitosan resins to TP accords with the Langmuir formula, and the saturated adsorption capacity is 1116 mg/g.

This study aimed to investigate the effects of tea polyphenols or the monomers (ECG, EGCG, and so on) on foaming property of egg alblumen protein by using electric beating machine and through direct measurement. It was found that 0.2% to 0.4% content of tea polyphenols is appropriate content to improve the foaming property of egg alblumen protein and that the active hydroxyl is the main reason for the improvement. Meanwhile, the effects of processing environmental factors affecting the interaction between tea polyphenols and protein were explored preliminarily.

The content of triterpenes extracted from sclerotia of Poria cocos was determined by colorimetry with vanillin-glacial acetic acid and perchloric acid, and the in vitro antibacterial activity of triterpenes was tested by plate growth rate method. The positive results of chemical reactions indicated that methanol extract of sclerotia of Poria cocos contains triterpenes and the content is 1.58%. Its lowest antibacterial concentrations are 0.47, 0.47, 0.95 μg/ml against Escherichia coli, Staphylococcus aureusm, and Pseudomonas aeruginosa respectively. The results also showed that the inhibitory activities of this sclerotia extract against Escherichia coli and Staphylococcus aureusm are relatively stable and hardly affected by time. In conclusion, the triterpenes extracted from sclerotia of Poria cocos have good antimicrobial activity and could be further developed as drug of treating suppurative infection and natural cosmetic of dispelling blain.

Particle size and hygroscopicity of KAC, MCC and SiO2 were measured, and anticaking functions of these three substances added into chicken flavor powder were compared at different amounts and environmental conditions. The results showed that the smaller particle size has the better anticaking function, and when the particle size is 20 to 30 μm, the anticaking function is excellent. Furthermore, the flowing and anticaking property of chicken flavor powder added with 3‰ KAC are obviously better than those of chicken flavor power added with 1% MCC or 1% SiO2 at relative humidity 90%±3% and 25± 1℃, relative humidity 75% ± 3% and 25 ± 1℃, and relative humidity 30% ± 3% and 25 ± 1℃, respectively.

Freeze-drying is a major way to produce lactic acid bacteria and probiotic powders, and both freezing and drying can influence the cell survival. In order to evaluate the damage of Bifidobacterium infantis caused by freeze-drying, microstructure, β-galactosidase activity and concentrations of Na+ and K+ were determined in this experiment. The results showed that the changes of microstructure, β-galactosidase activity and concentrations of Na+ and K+ increase during freezing and drying processes, which include concentration of cytoplasm, separation between cytoplasm and cellular wall, shrinking and damage of cell, increase of cell membrane permeability, decrease and disparity between Na+ and K+ concentrations.

Gelatin was cross-linked with tannic acid as cross-linking agent. Gel properties and degradation characters of crosslinked gelatin were evaluated. Microcapsules were prepared with cross-linked gelatin as wall material and vitamin B1 as core material. Release characters of core material in microcapsules were analyzed. The results showed that the minimum concentration of cross-linked gelatin to form gel is identical to raw gelatin at about 0.6%. However, the gel strength of cross-linked gelatin is lower than that of raw gelatin at the same concentration. Degradation study in vitro showed that the raw gelatin and cross-linked gelatin are hardly degraded in simulated gastric fluid, but both of them are degraded in simulated intestinal fluid, and the cross-linked gelatin is degraded slower than the raw gelatin. The microcapsules with cross-linked gelatin as wall material show certain slowrelease property in simulated gastric and intestinal fluids.

Taking emulsion forming in the aqueous-enzymatic extraction of peanut oil as study object, the amino acid composition, emulsion ability index, emulsion stability, secondary structure of adsorbing protein in emulsion surface, protein in continuous phase and peanut protein were compared respectively. The results indicated that the content of hydrophobic amino acid, emulsion ability index and emulsion stability of adsorbing protein in emulsion surface are higher than those of the protein in continuous phase and peanut protein. The rheological characteristics of the emulsion showed that the emulsion is a typical elasticity system, and the emulsion stability could be reduced by increasing temperature and shear rate.

The active proteins from Dasyatis akajei liver were isolated by precipitating with ammonium sulfate, chromatographing with Sephadex G-150. Then the activities of scavenging superoxide radical and hydroxyl radical and inhibiting lipid peroxidation were determined. The results showed that the isolated three protein peaks (P1, P2 and P3) could effectively scavenge superoxide radical and hydroxyl radical and inhibit lipid peroxidation. The inhibiting ability of P3 is the highest, while that of P1 is the lowest. In conclusion, the active proteins from Dasyatis akajei liver have antioxidation.

Silica gel column chromatography was used to separate and purify total alkaloids from Fritillaria ussuriensis Maxim. The solid phase was thin layer chromatography silica gel G and the mobile phase was ethyl acetate-methanol-ammonia (17:2:1). The purities of the separated products, pemine and peinine were determined using HPLC-ELSD. They are 93.19% and 92.09%, respectively. In conclusion, the separation method of silica gel column chromatography applied in this experiment can be used to gain highly purified products.

Mung bean, potato, sweet potato, rice and corn starches were isolated and their physico-chemical properties were compared respectively. Amylose leaching and setback (SB) are the highest for mung bean starch, and they are both highly correlated to apparent and total amylose content. Though mung bean starch has the highest amylose content, yet it does not show thermalpaste stability. The results showed thatduring heating sweet potato starch granules swell rather freely with bad thermal-instability and low retrogradation, indicating hign swelling power, peak viscosity (PV) and breakdown (BD), and low syneresis of the sweet potato starch, while rice starch shows the inverse. The gel consistency is also different among various starches, with potato starch the highest, and rice starch the lowest. The syneresis shows no obvious correlationship with amylose content and seems to be affecfed by other factors.

The change of scavenging activity on hydroxyl free radical of antioxidant peptide from Decapterus maruadsi was selected as the index to investigate the effects of temperature, pH, food materials, preservative, metal ions and different drying ways on the antioxidation stability of the peptide. The results showed that the antioxidant peptide from Decapterus maruadsi has a strong heat-resistant ability; It can keep high activity in the acidity environment, but loses its activity in the alkali environment; Some food materials, such as sucrose, NaCl, etc have little effects on its antioxdation stability while glucose and sodium benzoate can reduce its activity; All of K+, Ca2+, Mg2+, Zn2+ and Cu2+ can affect the stability, and the order is Cu2+＞Zn2+＞Ca2+ ＞K+＞Mg2+; And freeze-drying is better to keep the antioxdant activity of peptide from Decapterus maruadsi than spray-drying.

Analysis of contents and bioavailability of minerals in food is one of the important research points in the field of food processing and food nutrition in recent years. Contents of iron, zinc and calcium in baked foods such as bread, biscuit and cake, which were collected at supermarkets in Beijing, were analyzed, and the bioavailability of these minerals was evaluated by in vitro model as well. It was shown that among the three types of baked food, bread contains the highest contents of iron and zinc, and higher calcium than cake. Bread is a potential source for dietary minerals, while biscuit is a good source for calcium. However, bioavailability of minerals in bread is the lowest. Bioavailability of iron and zinc in cake, and that of calcium in biscuit is the highest.

Rheological properties of xanthan and welan gums were studied, and their viscosity affected by concentration, temperature, shearing rate, pH, freezing-thawing and cold store was compared in this study. A novel kind of microbial exopolysaccharides, welan gum shows wide application future due to its high temperature stability, pH tolerance and good environment-friendly properties.

Antioxidative Activity of Extracts from Viola tianshanica Maxim. was measured by Na2S2O3-I2 titrimetric method. The results showed that the antioxidative activities decreased in the order of 85% ethanol solution extracts ＞ acetone extracts ＞ chloroform extracts ＞ ethyl acetates extracts＞ methanol anhydrous extracts ＞n-hexane extracts.The amount of extracts used is directly inproportion to the anti-oxidative effect.When the control experiment was performed by using VC and VE, it is showed that 85% ethanol solution extracts of Viola tianshanica Maxim.(0.5%W/V) have stronger antioxidant activity than 0.02%VC(W/ V), but 0.02%VE(W/V) have no antioxidant activity.

Objective: To clone, express and identify the gene of Gal d 3 in eggs. Methods: The total RNA was extracted from eggs, and the gene of Gal d 3 was amplified by RT-PCR and cloned into pMD18-T for sequencing. Then the interesting gene was subcloned into pET-28a for expression. After purification of the recombinant protein, its IgE-binding capacity was determined by Western blotting. Results: The gene of Gal d 3 in eggs is obtained by clone, which has 2118 bp and encodes 705 amino acids. This isoelectric point of the encoded protein is 6.5 with a molecular weight of 76000. Conclusion: The main allergen gene Gal d 3 in eggs is successfully cloned and expressed in this study, and this recombinant protein shows good IgE-binding capacity.

L-lactic acid is increasingly used as feedstock for potential biodegradable plastics. With the aim to achieve efficient production and high productivity, it is important to optimize the fermentation process for an industrial strain, genome shuffled strain Lc-F34. Temperature and pH play important roles in the lactic acid batch fermentation process. Their effects on L-lactic acid production were studied using central composite design. According to the regression model, the maximum L-lactic acid yield can be obtained at pH 5.5 and 40.2 ℃.

This study aimed to optimize the fermentation conditions for nattokinase production by Bacillus subtilis Natto with response surface methodology. Firstly, Plackett-Burman design was used to evaluate the effects of related factors on nattokinase production. It was found that soybean powder concentration is the most signficant positive factor, followed by concentrations of glucose and CaCl2 (negative factor). And then, the concentrations of soybean powder, glucose and CaCl2 were further optimized using response surface analysis. Results revealed that the optimal medium constituents for liquid fermentation are as follows: glucose 1%, soybean powder 3%, KH2PO4 0.2%, K2HPO4·3H2O 0.26%, MgSO4·7H2O 0.1% and CaCl2 0.12%. The optimized conditions allow nattokinase production to increase from 1800 U/ml to 2226.06 U/ml.

Lactobacillus acidophilus and traditional lactic acid bacteria were adopted to make fermented soybean milk. Effects of adding ascorbic acid in culture medium on the survival of probiotics were studied in fermented soybean milk. The results showed that adding ascorbic acid could keep the best survival of probiotics. Under the conditions of 39 ℃, fermentation starter amount 6% and ascorbic acid amount 0.01%, the flavor of the obtained fermented soybean milk is better, and its nutritive value is also higher. The survival number of probiotics is 6.3×108 CFU/ml.

Two strains of fungi (C4 and G1) producing high activity xylanase were isolated by soil dilution coating method and through primary and repeated screening. Furthermore, the optimum carbon source for their growth and enzymological properties of xylanases produced by them were studied. The results showed that the best carbon source for strain C4 producing xylanase is the mixture of corncob and bran. The xylanse activity produced by strain G4 reaches the peak after cultivation for 24h, 6582. 29 U/ml. The optimum reaction temperature of the xylanse is 40 ℃ and it is relatively stable below 50 ℃. Its optimum reaction pH is 5.0 and it shows good pH stability; The best carbon source for strain G1 producing xylanase is corncob. The xylanase activity produced by strain G1 reaches the peak after 96 hours of cultivation, 6301.04 U/ml. The optimum reaction temperature of xylanase produced by strain G1 is 40 ℃ and it is stable below 40 ℃. The optimum reaction pH is 5.0, but its stability is less than that of xylanase produced by strain G4.

The comparison among the activities of isoflavone-glucosidases isolated from 32 species of plants showed that chickpea (Cicer arietinum)β-glucosidase activity is the highest. Then the chickpea β-glucosidase was purified by 10.1 folds with the yield of 7.2% after ammonium sulphate precipitation, DEAE-Cellocuse -52 ion exchange and Sephadex G-100 gel filtration chromatography. This purified enzyme has a molecular weight of about 73.2 kD and two subunits. The optimum temperature, pH and Km towards genistin and daidzin of this enzyme are 45 ℃, 6.0, 11.0 μg/ml and 19.0 μg/ml, respectively. This β- glucosidase is stable at pH and temperature range of 4.0 to 6.5 and 30 to 45 ℃ respectively. Furthermore, this enzyme can effectively hydrolyse genistin and daidzin, but be strongly inhibited by Ag+, Hg2+ and D-glucono-δ-lactone at a concentration of 1 mmol/L.

α-Amylase was immobilized on five 3-aminopropyl silica gels with glutaraldehyde as crosslinking agent. Some factors that affect the activity of immobilized α-amylase were investigated, such as the mesh of silica gel, concentration of glutaraldehyde, reaction temperature and pH. The properties of imm obilized and free α-amylases were also compared. The results indicated that the optimum temperature of the immobilized enzyme is 75℃, which is 10℃ higher than that of the free α-amylase, and its thermal stability is better than that of free enzyme. Compared with free α-amylase, the immobilized α-amylase is also markedly improved in acid and alkaline stability, storage stability and operation stability. Furthermore, the Michealis constant (Km) of immobilized α-amylase is 2.13 mg/ml, while that of free α-amylase is 1.02 mg/ml.

The polyphenol oxidase (PPO) of lotus root was extracted and purified by four steps: ammonium sulfate fractionation with saturation 30% and 80%, and DEAE-Sephadex A-50 and Sephadex G-75 column chromatography in turn. SDS-PAGE analysis showed that the purified PPO is a single polypeptide with a molecular weight of about 21.0 kD. The final purification fold and the yield of PPO are 103 and 0.38 %, respectively.

Micronucleus test was designed to study effects of Cordyceps militaris polysaccharides on micronucleus rate of Vicia faba root-tip cells induced by ultraviolet (UV). The results showed that the inhibition rates of Cordyceps militaris endopolysaccharides and exopolysaccharides at the concentrations of 30 , 50 , 80, and 100 μg/ml respectively on micronucleus of Vicia faba root-tip cells induced by UV are lower obviously than the positive control group. When the concentration of both endopolysaccharides and exopolysaccharides is 100 μg/ml, their inhibition rates against micronucleus reach 47.68 % and 43.04 % respectively. There are significant differences among the effects of four concentrations of Cordyceps militaris polysaccharides on micronucleus (p ＜ 0.01). In addition, with the increase of the concentration of polysaccharides, the micronucleus rate of Vicia faba root-tip cells decreases. In conclusion, endopolysaccharides and exopolysaccharides from Cordyceps militaris could inhibit the yield of micronucleus of Vicia faba root-tip cells induced by UV.

To utilize the high efficiency of glaA expression cassette of Aspergillus awamori and Agrobacterium-mediated transformation in the construction of A.awamori expression vector, a 2.1-kb glaA promoter fragment including signal peptidecoding sequence and a 1.1-kb glaA terminator fragment were amplified from the genomic DNA of A.awamori strain SG1 by PCR and then fused to form a foreign gene expression cassette. The Agrobacterium tumefaciens binary vector pCAMBIA1302 was used as backbone and its T-borders and necessary elements for E.coli and Agrobacterium-mediated transformation were retained whereas other regions in the vector were deleted. The foreign gene expression cassette described above and the filamentous fungal functional hygromycin B resistance marker from pAN7-1 were inserted into the region between T-borders. Finally a secretory integration Agrobacterium-mediated A.awamori expression vector pSUAA52am was constructed. Transformation experiment showed that transformation efficiency of pSUAA52am into A. awamori with protoplast method was 21 transformants/106 spores, while that with Agrobacterium-mediated method reached 1106 transformants/106 spores, 53 folds of the former. This indicated that the construction of this expression vector is successful.

Concanavalin A (ConA), which has a very strong interaction with glycoprotein, was immobilized on preactivated glutaraldehyde-modified chitosan microspheres, and then oriented immobilization of glucose oxidase was carried out on the strong interaction. The optimal immobilization conditions are as follows: glutaraldehyde concentration 0.1%, ConA concentration 0.02 mg/ml and glucose oxidase concentration 0.08 mg/ml. The optimum pH and temperature for orientedly immobilized glucose oxidase are 4.0 and 57 ℃ respectively, and its Michaelis constant (Km) is 15.84 mmol/L. Compared with the free and the randomly immobilized glucose oxidases, the optimum pH of the orientedly immobilized glucose oxidase tends more acidic and its pH range is wider. Orientedly immobilized glucose oxidase also presents the higher temperature resistance and the better affinity to the substrate.

Objective: It is very important to obtain high yield mutant strain on the base of key enzyme activity analysis of A. succinogenes for the industrial bioconversion of succinic acid from crop straw. Methods: The pentose and hexose hydrolyzed from crop straw hydrolyzed by dilute sulfuric acid were determinated using HPLC. During the fermentation of the hydrolysate, the activities of key enzymes were determinated and regulated. In order to decrease ethanol yield, those strains mutated by soft X-ray of synchronous radiation were screened out on the plates with high concentration of allyl alcohol. Then the alcohol dehydrogenase activity of the mutant strain was compared with that of the parent strain. Results: Determination of the hydrolysate showed that about 47 g glucose and 26 g xylose are from 200 g hydrolyzed crop straw. Pepck , Pc and Mdh are identified as the key enzymes of succinic acid metabolism and the high activity of Adh causes the cumulation of ethanol. Determination of end products from the parent strain indicated that the concentration of ethanol is the highest among those byproducts and that the yield of succinic acid and byproduct ethanol are 54.2 g/L and 8.9 g/L, respectively. Compared with the parent strain, the ethanol concentration produced by anti-allyl alcohol mutant strain S.JST01 decreases by 84%，from 8.9 to 1.4 g/L. Meanwhile the yield of succinic acid increases by 16%, from 54.2 to 63.1 g/L. Enzyme determination showed that the activity unit of alcohol dehydrogenase (Adh)decreases from 614 to 108. Conclusions: The interdiction of metabolic pathway of Adh decreases the metabolism prosuced by ethanol accordingly, thus the succinic acid flux is strengthened by the redundant carbon flux from the byproduct. Furthermore, the mutant strain S.JST01 with the end product yield of 63.1 g/L succinic acid is worth applying to industrial fermentation.

The modification of galactomannan from fenugreek seed by cellulose, pullulanase or cellulose-pullulanase combination was introduced. Then the microstructure, particle shape, crystallinity and thermostability of original galactomannan and modified galactomannans were characterized with fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimeytry (TG) and differential thermal analysis (DTA). The results showed that the molecular weights of modified galactomannans are 1.16×105, 2.19×105 and 5.10×104, and the yield of reducing sugar are 5.1%, 39.5% and 43.8%, respectively. The analysis of FT-IR indicated that the chemical structures of residues are not modified during the hydrolysis process. The significant effects of degradation on the crystallized area of fenugreek gum can be observed by XRD analysis, and the degradation reaction mainly occurs in the non-crystalline region of fenugreek gum. SEM analysis showed that the whole molecular constitution is broken, and modified galactomannan granules are dissimilar in size with original galactomannan. According to the analyses of TG and DTA, the weight-loss temperatures of modified galactomannans increase, and they have higher thermostability and lower rate of weight loss.

A strain MM01of fungus was isolated for producing unsaturated fatty acid. It was found experimentally that 56 mg of total fatty acids are contained in 1 g of dry mycelia of the strain, which consist of oleic acid (37.330%), linoleic acid (10.943%) and γ - linolenic acid (18.783%). The strain was identified as Actinomucor elegans.

Buckwheat is a common allergen in plants. In the present study, a full-length cDNA encoding 515 amino acid residues was amplified and cloned from the total RNA of tartary buckwheat by PCR and RACE methods. Its nucleotide sequence has high homology with main allergenic storage protein mRNA in common buckwheat. The recombinant allergenic protein of tartary buckwheat (rTBt) expressed in Escherichia.coli BL21 (DE3) was purified by using affinity chromatography and it can specifically bind to the IgE in patients serum with protein allergy of tartary buckwheat. These results make an important foundation for further study about the mechanism and function of the major allergenic protein in tartary buckwheat.

Objective: Shellfish is one of the best edible proteins for human. It is also commonly identified as a source of food hypersensitivity, and ingestion of shellfish may cause severe allergic reactions such as anaphylactic shock. The potential risk of shellfish allergy is worth paying more attentions. Method: Meretrix meretrix Linnaeus was selected as the material, and the muscle protein was extracted with a triturator. Nine cases of shellfish-allergic serum and six cases of normal serum were obtained through questionnaire survey and identified with allergen kit. SDS-PAGE and Western blotting were applied to identify the components and characterizations of specific allergen of Meretrix meretrix Linnaeus. Results: There are eight sections of protein with relative molecular weight of more than 200 kD, 200, 90, 80, 70, 46, 36, and 24 kD in SDS-PAGE, respectively. Eight cases of shellfishallergic serum show IgE-binding capacity to the protein with relative molecular weight of 90 kD in Western blotting. The 90-kD protein accounts for 10% to 20% of the muscle protein of Meretrix meretrix Linnaeus, and mainly is salt-soluble protein. Conclusion: The specific allergenic component in Meretrix meretrix Linnaeus is identified as a 90-kD protein.

Genome DNA extracted from mold in koji was acted as model in the partial 18SrDNA sequence-amplified reaction by PCR. The DNA sequences were inserted into screening vector pKRX-T, and then were transformed into E.coil HB101. The results of sepuencing and simlarity analysis showed that the mold strain is similar to Rhizopus oryzae at 99 %. This strain might be regarded as mutant of Rhizopus oryzae.

“Xiangwei” mushroom was cultured in liquid medium in shake flask. With mycelia yield as investigation index, the liquid medium formula was optimized by orthogonal test．The results showed that the optimal medium compositions are as follows: glucose 2.0%, beef extract 0.2%, KH2PO4 0.25% and MgSO4·7H2O 0.15% .

This article mainly using feedback inhibition of glucose feeding, modulating pH value of fermentation broth, as well as alkalinity neutral and fed- batch culture compound culture to study the high-density culture of the Lactobacillus Bulgaricus. The research indicated, alkalinity neutral and fed-batch culture compound culture conditions as follows: when Lactobacillus Bulgaricus cultivated for 18h or 26h, supplementing batch fluid 5ml in culture fluid the carbon nitrogen ratio is 0.67, and adjust pH value to 6.5 every 1.5h , after raising 36h, the highest thalline concentration of Lactobacillus Bulgaricus is 9.02×1011 CFU/ ml, dry weight of thalline is 14.266 g/L.

β-Galactosidase was immobilized on chitosan microspheres with glutaraldehyde by cross-linking reaction, the immobilezation conditions and characterization of the immobilized enzyme were studide. The optimal conditions for immobilization were as follow:in pH6.5 P-E-M solution for 10 h, chitosan microsphere was treated with 0.5% glutaraldehde at 25℃ for 12h,the solution ofβ-galactosidase was immobilized on the carrier at 4 ℃ for 12 h, enzyme activity recovery was 67%. Optimal temperature and pH for the immobilized enzyme were about 40 ℃ and 7.0 respectively,apparent michealis constant of immobilized β-galactosidase Km=0.613mmol/L.The stability of immobilizedβ-galactosidase was high after storage. It exhibited excellent operational stability．With 5% lactose as the substrate，the lactose hydrolysis was maintained at 90% after 6 cycles；the lactose hydrolysis was kept at 75% when the immobilized lactase was applied in the column chromatography reactor after 20 days.

Objective: The artificial antigens were synthesized by derivative of clopidol and BSA、OVA.Methods: The derivative of clopidol, called as CLOP-2C, was synthesized by Williamson method in this study. Then two artificial antigens of clopidol(CLOP-2C-BSA, CLOP-2C-OVA) were prepared by active ester method (AE) and mixed anhydride method (MA) respectively. Results: CLOP-2C is identified by TLC, MS, IR spectrum . The characterization of hapten-protein conjugates were examined by ultraviolet spectrophotometry. The numbers of hapten molecules per molecule of protein estimated by ultraviolet spectrophotometry according to the absorbance of compounds at 280 nm for two conjugates were 8.26 and 4.7 respectively Conclusion: The artificial antigens were synthesized successful.

Centrifugation conditions for isolate exopolysaccharide produced by Lactococcus lactis subsp. lactis, concentration multiple of exopolysaccharide solutiom via rotary evaporation, alcohol precipitation conditions and protein removal nethod were studied, as well as the antioxidant activity of the obtained exopolysaccharide by the above procedures. The results indicated that the yield of the exopolysaccharide can reach the highest under the centrifugation conditions of speed 6000 r/min, time 15 min and temperature 15 ℃, concentration multiple 4 times, alcohol precipitation conditions of 90% alcohol volume 3 times as much as exopolysaccharide solutiom and precipitation time 12 h, and concentration of TCA for removing protein 10%. The exopolysaccharide has distinct antioxidant ability in vitro.

Metabolic flux analysis model of β-carotene in Spirilina was established based on data of cell composition, flux distribution of Spirilina cultured at different temperatures was analyzed according to this model. Analysis results showed that temperature has an obvious effect on β-carotene metabolic flux, and when cultured at 33℃ the flux is maximum. Activities of 11 enzymes in β-carotene biosynthesis pathway of Spirilina cultured at a temperature gradient were measured, and then correlation and components analysis were used to investigate the regulation controlls of these enzymes to β-carotene metabolic flux. Subsequently, a new parameter Cci was constructed to reflect these controlls based on correlation and components analysis, which is very similar to the metabolic control coefficient. The results showed that ribulose-1,5-bisphosphate carboxylase (CcRuBisCO=0.296), glucse-6-phosphate dehydrogenase (CcG6PD=0.23) and pyruvate dehydrogenase (CcPDHC=0.221) have higher control coefficient, indicating that they play primary roles in control of flux, however, the coefficients of α-ketoglutaric dehydrogenase (Ccα-KGDHC=－0.102), phosphoglyceromutase (CcPGM=－0.081) and isocitrate dehydrogenase (CcICDH=－0.074) are negative, conformed that they have negative control to flux.

75 male Kuming mice were randomly divided into control, sodium selenite, organic-selenium (Se) with inactivated probiotics, Se-enriched probiotics or probiotics groups (n=15) in the experiment, and all the mice were fed for 30 days. The growth performance, Se concentration in blood and skeletal muscle, anti-oxidation status and resident intestinal flora of each treatment group were studied to compare their differences. The results indicated that the body weights of mice fed Se-enriched probiotics diet are higher than those of others after fed for 30 days. Anti-oxidation status and Se concentration in blood increase when Se is supplemented; however Se content in skeletal muscle of the mice fed inorganic or organic Se is lower than that of mice fed selenium-enriched probiotics. The composition of resident bacterial flora in gut is enhanced when mice are fed with probiotics. In conclusion, the measured indexes of mice fed selenium-enriched probiotics are markedly better than those of other groups.

1.05% of 4 kinds of dietary chitosans with different molecular weights (Mw) and degrees of deacetylation (DDA) (high molecular weight chitosan HCS with Mw 7.60×105 and DDA 85.5%, middle molecular weight chitosan MCS with Mw 3.27×104 and DDA 85.2%, chitooligomer COS with Mw 0.99×103 and DDA 85.7%, and water-soluble chitosan WSC with Mw 3.91×104 and DDA 52.6%) were fed to mice for 90 days. No abnormal symptoms, clinical signs or deaths were observed during the feeding period. The body weights of mice between chitosan groups and control group show no significant difference. HCS almost has no effect on the levels of lead in liver, spleen, heart and kidney. COS and WSC decrease the levels of lead in liver, spleen and heart. However, MCS significantly increases the level of lead in liver.

The study aimed to investigate the effect of dietary Eupolyphaga sinensis Walker (EW) and its mutant (columnar Eupolyphaga sinensis Wal ker, CEW) on lipid metabolism in hyperlipidemic mice. Forty eight male Bal b/C mice were randomly divided into 4 groups, normal group (cholesterol free AIN76 diets), model group (1% cholesterol diets), EW group (10% EW powder and 1% cholesterol diets) and CEW group (10% CEW powder and 1% cholesterol diets). After 3 weeks, serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) levels were determined. Hepatic lipid concentrations (TG and TC) were also determined. The results showed that CEW significantly decreases the concentrations of serum TC (10%, p<0.05), TG (22%, p<0.001) , LDL-C (16.3%, p<0.05) and hepatic TG (53%, p<0.001). On the other hand, EW does not effect the concentrations of serum TC, LDL-C, hepatic TG or hepatic TC, but significantly decreases the concentrations of serum TG (57%, p<0.001). Both EW and CEW significantly increase HDL-C levels (46%, p<0.001 and 16%, p<0.05 respectively), and decrease atherosclerosis index (33%, p<0.001 and 23%, p<0.001 respectively). In conclusion, this study indicated that there are significant different effects on lipid metabolism in hyperlipidemic mice between EW and CEW. The hypocholesterolemic effect of CEW is better than that of EW, but the hypoglyceridemic effect of EW is better than that of CEW in mice.

The effects of methyl paraben (MP) on the fecundity and growth and development of Drosophila melanogaster were studied in this experiment. After methyl paraben was administered to Drosophila melanogaster at different concentrations, the egg number produced by parental and filial generation, the period of development, the number of pupa and eclosion and the bodyweight were analyzed. The results showed that 0.2 percent of methyl paraben has obvious toxicity effects on Drosophila melanogaster but lower concentration of methyl paraben has potential estrogenic activities. 0.2 percent of methyl paraben decreases the number of egg, pupa and eclosion, the bodyweight of male and delays the period of development. 0.02 percent of methyl paraben increases the number of egg, pupa and eclosion and shortens the period of development.

The total content of bromophenols in red alga Polysiphonia urceolata extract (PUE) was detected by FD method. The antioxidant effects of PUE were detected on mice. The oxidative DNA damage of peripheral lymphocytes induced by H2O2 was analyzed by SCGE. The concentrations of superoxide dismutase (SOD) and malonyldialehyde (MDA) in plasma were detected with test kit. The results showed that the concentration of total phenols in the PUE is proved to be 68.54 % and the PUE shows low toxicity with its LD50 more than 3160 mg/ kg. There is a significant decreasing tendency of the oxidative DNA damage of peripheral lymphocytes in the 40 mg/ kg bw dosage group induced by 10 μmol/ L H2O2. The levels of MDA in all dosage groups are less than that in the control group. In conclusion, the PUE has some anti-lipid peroxidation activity.

Fifty-eight male SD rats were randomly divided into two groups, the control group (n=10) fed with basal diets and the model group (n=48) fed with high-fat diets for 3 weeks. Then hyperlipidemia rats were divided into 4 treatments (n=10), high lipid control treatment, low-dose, medium-dose and high-dose oat β-glucan treatments, which were fed high-fat diets plus different contents of oat β-glucan (0, 6,12 and 24 g β-glucan/kg, respectively) for 6 weeks. The levels of TC, TG, LDL-C , HDLC, ApoAI and ApoB in plasma were measured at the states of limosis (Rats were fasted for 12 h) and postprandial 2 h (Rats were fasted for 16 h and then fed 5 g diet), respectively. Hepatic lipids were also measured at the end of experiments. The results showed that compared with high lipid control group, the contents of TC, LDL-C and ApoB in plasma are significantly decreased in three oat β-glucan groups of hypolipidemic rats at the state of limosis. Three doses of β-glucan also can significantly improve postprandial plasma lipid distribution and reduce hepatic cholesterol and triglyceride concentrations. Furthermore, the difference among three doses of oat β-glucan was observed in this experiment.

Hygromycin B phosphotransferase gene (hpt) has been widely used in the process of gene construction when agricultural plants are modified by biotechnology. Hpt protein as an introduced “new” protein was obtained from sources with no prior history of causing allergy, thus its safety assessment was mainly focused on comparison of amino acid sequences, in vitro digestibility and animal model according to the IFBC-ILSI. Individual sequence analysis with known amino acid sequences, reported as allergens, showed that no eight continuous amino acids are observed; Hpt protein is unstable to heat for its complete decomposition at 80 ℃ for 10 min. It is also digested within the first 20 min by simulated gastric fluid treatment as observed by SDS-PAGE and Western blotting. BN rats were used to establish allergenicity model. The levels of IgG, IgE and histamine were tested by ELISA. The results showed that the Hpt protein has significant difference with the positive (p ＜ 0.05), but no difference with the negative. In conclusion, Hpt protein has low probability to induce allergenicity. The results can provide basic data for evaluating the safety of genetically modified plants which use hpt as marker gene.

The purpose of the study was to investigate the effects of xylose on intestinal microflora in mice. Mice were orally administered with xylose at different doses, and then the numbers of Bifidobacterium, Lactobacillus, Enterobacter and Enterococcus were counted, respectively. The results showed that xylose can regulate and improve the intestinal flora and efficiently stimulate the proliferation of Bifidobacterium in mice.

Objective: To develop health drink containing functional ingredients of perille and to evaluate its antioxidant effect. Methods: Perilla extract was obtained from the fresh purple perilla leaves by the steps of pretreatment, enzymolysis and acid extraction. The best formula of drink was determined by orthogonal test and sensory analysis. Then experimental mice were fed the perilla drink for 28 days and their blood samples from eyes were collected. Finally, the level of malondialdehyde (MDA) and the superoxide dismutase (SOD) activity in serum were analyzed with reagent kits. Results: The perilla health drink obviously reduces the serum MDA level (p＜0.05), and significantly improves the SOD activity (p＜0.05) in mice. Conclusion: Perilla health drink has antioxidant and delay-aging function for mice.

Experimental data extensively suggest that the proteolysis of endogenous proteases is the key reason for meat tenderization. Cathepsin is one of these proteases, and it has the proteolytic function. This article briefly described the stability of lysosomal cathepsins and their expression in myofibrillar. Also, the classification of cathepsins, influence factors on their activities, their contribution to meat tenderization, their isolation and purification, methods for assaying activities as well as their application prospect were discussed in this article.

Polymethoxylated flavones (PMFs) are one of several distinctive classes of flavonoids in citrus fruit, mainly existing in citrus essential oil. PMFs have significant biological activities especially anti-cancer activity, and become a key and hot topic of further processing researches on citrus byproduct recently. This paper summarized properties, structures, contents and distribution of PMFs in citrus, reviewed the technological progresses of analysis, separation and purification of PMFs, and finally discussed the research and development tendency of PMFs in the future.

Milk-derived antioxidative peptides are composed of 2 to 20 amino acids. The antioxidant activity of peptides has important relationship with the characteristic amino acid sequences. The production, isolation and properties of antioxidant peptides from milk were reviewed, different antioxidation assay methods were compared, the applications of antioxidatnt peptides in food were introduced and the future directions of milk-derived antioxidant peptides were put forward in this paper.

Risk assessment has received recognition and applications in the field of agro-products and food safety in the early 1990s. In this paper, current situations and advances about EU consumer dietary exposure risk assessment were summed up, involving the principle, foundation, measures and mathematical modeling of consumer dietary exposure risk assessment. Some information in the course of developing consumer dietary exposure risk assessment were generalized , such as, the data collection and statistic methods of chemical substance residue concentration, food consumption, body weight and toxicological reference value. POCER model in Belgium and Consumer model in UK that were used for assessing consumer dietary exposure risk were introduced. Considering the current research advances of consumer dietary exposure risk assessment in China, the feasibility of two assessment models mentioned above was summarized. Research achievements of EU relating to consumer dietary exposure risk assessment are provided with significant instruction meanings to future research carried on in China.

Nowadays, more and more people are concerned about food safety. But recently a study showed that acrylamide, a toxic and potentiall cancer causing chemical, would be formed in many types of food prepared or cooked at high temperatures, especially in starch-rich food. Since the toxicity on nerve system and DNA and potential carcinogenicity, it is very important to control the level of acrylamide in food. This paper reviewed some methods for controlling the formation of acrylamide in food based on the formation mechanism of acrylamide.

The model of risk assessment for APFO in packaging materials was established from its resources, releasing and migrating routes, and possible exposures. With common methods used in other dangerous chemicals and based on the determination of LC-MS-MS, the immigration curve of APFO was studied. According to related data, the limit for APFO in packaging materials is proposed as 0.05 mg/m2.