Abstract:In recent years,fruits and vegetables industry had got great success in china,and fresh-keeping technology also developed rapidly.However,with the rising of people’s living standard ceaselessly,as well as the widely attention to the food safety,new requirements for fruits and vegetables were put forward to fresh-keeping industry,which was natural,safety and nutritive.Therefore,the development of new fresh-keeping technology had been paid great attention.In this paper the comprehensive situations and safe conditions of fresh-keeping technology on fruits and vegetables were analyzed domestic and abroad.The research directions of fresh-keeping in China were indicated.These could provide some reference for other researchers.

Abstract:The research status on vacuum oil bath dehydration technology was summarized,involving the principle of vacuum frying,pretreatment,vacuum oil bath dehydration technology research history and the latest research progress.The problems existing in the vacuum oil bath dehydration technology was analyzed,the prospects of its application and technology development trend were discussed.

Abstract:The by-products of rice milling,such as the broken rice,rice bran,and rice husk etc.,have not been fully utilized in China.In this manuscript,we reviewed the progress in the comprehensive utilization of rice milling by-products worldwide.This article may help people to improve the utilization and edible rates of the rice grain,and to enhance China’s food security by the deep processing of rice.

Abstract:Nano-silver has unique properties of nanomaterials and also has unique anti-bacterial and catalytic properties of silver.This paper has a brief introduction on the antimicrobial properties of nano-silver.Applications of nano-silver in food storage and processing like food packaging materials,nano-silver coating and other aspects are emphatically summarized.The potential safety issues of the silver nanoparticles are also discussed.

Abstract:Microwave heating is a rapid and convenient strategy for food-reheating.However,the phenomenon of uneven heating often occurs during microwave heating.To solve the "cold spot" problem during microwave reheating,a heat transfer model to predict the distribution of heat could help control the quality of food during microwave heating.Therefore,this manuscript summarized the recent advances in microwave heat transfer model,discussed the numerical calculation,theory and microwave absorption frequency of microwave heat transfer model,and analyzed the current issues and future development in this field.

Abstract:In order to improve the yield of acid from blue-green algae,four kinds of nutrients(Fe,Fe2+,Ni2+ and yeast extract) with different concentrations were added to the fermentation froth,respectively.It was demonstrated that the addition of nutrients can increase the acid production in different degrees when compared with that of the control.With the different addition dosages,the yield of butyrate and organic acids were both improved,which were 109% and 84% increasements for 0.50 g/L of Fe,148% and 102% for 0.10 g/L of Fe2+ and 131% and 88% for 0.20 mg/L of Ni2+.Among them,yeast extract demonstrated that the best effect,when 0.25 g/L yeast extract was added,the yield of butyrate and total organic acidsachieved at 6803 mg/L and 9269 mg/L,respectively,which were 90% and 64% higher than that of the control.

Abstract:Fabrication and its electrocatalytic property on glucose of platinum-palladium/unzipped carbon nanotubes(Pt-Pd/UCNTs) nonenzymatic biosensor were studied in this manuscript.Scanning electron mi-croscopy(SEM),X-ray photoelectron spectroscopy(XPS),and cyclic voltammogram(CV) results indicated Pt-Pd nanoparticles were well-dispersed on the surface of UCNTs/GCE;compared with UCNTs,Pd/UCNTs,and Pt/UCNTs modified electrodes,Pt-Pd/UCNTs modified electrode exhibited strong electro-catalytic activity toward glucose oxidation,such as faster catalytic respond and larger respond current,and had better selectivity.

Abstract:In order to block biosynthesis genes aprF and aprG of apramycin in Streptomyces tenebrarius Tt-49,recombinant plasmid pFD10 was introduced to S.tenebrarius Tt-49 by conjugation.And double crossover mutant Tt-49 G53 was obtained finally.Preliminary research on physiological characteristics for double crossover mutant Tt-49 G53 was conducted.The results showed that double crossover mutant Tt-49G53 grew more slowly than parent strain,the level of antibiotic production was 13 u/mL,which was 100 times lower than the level of parent strain.The metabolic products were analyzed by TLC.A pre-judgment of the result was that double crossover mutant Tt-49 G53 couldn’t produce apramycin.It was supposed that aprF and aprG were not closely related to secondary metabolism of S.tenebrarius only,but also was associated with the growth and development of producing strain.

Abstract:In this study,To accurately identify lactic acid bacteria(LAB) that were isolated from fresh yak milk and Qula in Sichuan region of China,nine LAB strains were classified and identified to species level by using 16S rDNA sequencing analysis,multiplex PCR assay of recA gene,hsp60-PCR-RFLP analysis etc.The results showed that nine LAB strains were initially characterized as Lactobacillus plantarum group(4 strains),Leuconostoc mesenteroides(4 strains) and Lactobacillus helveticus(1 strain) by 16S rDNA sequencing analysis.However,16S rDNA sequencing analysis could not distinguish between L.plantarum and L.pentosus.For further identification of strains in L.plantarum group,multiplex PCR assay of recA gene and hsp60-RFLP analysis were conducted.The results revealed that multiplex PCR assay of recA gene and hsp60-RFLP could identify L.plantarum group to species level and 4 LAB strains in L.plantarum group were identified as L.plantarum.

Abstract:Single-factor experiments and an orthogonal experiment were designed to obtain the optimum technological parameters.An effort was made to obtain the advantages of MWSB drying compared to samples hot-air dried,SB dried,vacuum-freeze dried and vacuum-microwave dried.The quality of production was determined by measuring rehydration rate,chlorophyll content,colour difference,energy consumption and sensory evaluation.The results showed the optimum processing parameters were microwave power 300 W,hot air temperature 68~78 ℃,hot air speed 8m/s in the earlier stage(10 min) and microwave power 200 W,hot air temperature 68~78 ℃,hot air speed 6 m/s in the later stage(45 min).The production of MWSB drying has higher rehydration rate,chlorophyll content,colour difference and sensory evaluation.than that hot-air dried,SB dried and vacuum-microwave dried,but a little lower rehydration rate and chlorophyll content than that vacuum-freeze dried.There is a significant reduction in energy consumption by using MWSB drying.

Abstract:The microbial community diversity, predominant species and its related characters ofthe product were investigated during the fermentation process of pickled wax gourd using the16S rDNA clone library. The results showed that in the pickling system Enterobacter, Lactococcus and Weissella are the predominant microbial community at earlier phase. After 15 daysof fermentation, the dominant population has changed to be Pediococcus pentosaceus, on day30 Enterobacter and Pediococcus become to be the predominant species. In the later stage ofpickling, the community system is stable, and Pediococcus, Weissella and Virgibacillus arethe major microbial species. At the same time, the pH value and nitrite concentration of pickledwaxgourd samples had been decreasing, its minimum values reached 3.7 and 0.5 mg/kg, respectively. The salinity value was finally stable in 7.0%. The total population of bacteria andlactic acid bacteria (LAB) changed from the high level to stable, the population of LAB was 1.0×107 cfu/mL at the later phase of pickled. Some species including Lactococcus, Pediococcusand Virgibacillus detected in the pickled wax gourd are very significant microorganisms inkeeping the quality of the product. These experimental results can also provide the critical ba-sis for the microbial ecosystem study and quality control of pickled wax gourd processing.

Abstract:In this study,the tolerance of 3 gram positive(Bacillus cereus,Staphylococcus aureus and Listeria monocytologene) and 3 gram negative bacteria(Vibrio parahaemolyticus,Salmonella and Pseudomonas fluorescens) topotassium sorbate were carefully studied by pure cultivation and simulation of food system.When 1 g/L potassium sorbate was presented in culture,the number of gram negative bacteria was reduced to up to 2~3.5 lg(CFU/mL),while those of gram positive bacteria were only reduce to 1 lg(CFU/mL).This results demonstrated potassium sorbate inhibited on the gram negative bacteria growth than that of the gram negative bacteria.Results of pure culture,minimal inhibitory concentration(MIC) and inoculation to instant kelp results all showed that the tolerance of gram positive bacteria is better than gram negative bacteria.It may have significance in the application of potassium sorbate on the control of gram positive bacteria.

Abstract:In this manuscript,Laiyang pear was as research model to demonstrate the physiological mechanism of aging under micro-vacuum storage.For this,pear at store under micro-vacuum storage at the pressure of 66 661~79 993.2 Pa and the temperature of 3±1 ℃,and the parameters such as CAT,SOD,POD,O2-· and H2O2.The relationship among LOX activity and MDA,membrane permeability was also studied.The results showed that the micro-vacuum storage could significantly improve the activity of SOD,CAT,POD.When compared that of atmosphere storage but decrease the activity of LOX,the content of O2-· and H2O2.Furthermore,atmosphere storagedelay the relative electric conductivity and the increasing of MDA(P≤0.05).The experiment indicated that the micro-vacuum storage could reduce the reactive oxygen species and the damage of membrane to decrease the lipid peroxidation degree then to maintain membrane structure and function.

Abstract:The aim of this study is to find a way to reuse of kelp waste with higher value.For this,kelp waste was fermented in liquid by Hypsizigus marmoreus JB06,and the polysaccharides were got through sedimentation by ethanol.The activity of anti-free radical and total antioxidant of polysaccharides was detected by using the Kit.The results showed that at the 0.5 mg/mL,the inhibition rate of hydroxyl radical of the polysaccharide was higher by 11.34% than that from the solution of pure kelp waste.At the content of 8mg/mL,the inhibition of superoxide anion was higher by 9.52 % than that from the solution of pure kelp waste;the total antioxidant activity was increased by 13.20%.Based on the above results,it can conclued that the antioxidant capacity was significantly increased by fermentation.

Abstract:To improve the superoxide dismutase activity of Rhodotorula marina,a screen method with paraquat as drug was introduced in this study.Though gradually increasing of paraquat content in medium,a stain with of high superoxide dismutase activity(increased by 35.2%) was screened.Based on this,the effect of different oxidative stress to the growth,superoxide dismutase activity and astaxanthin content was investigated.The results indicated that 0.075 mmol/L paraquat could improve the superoxide dismutase activity by 103.7% when compared with that of the control,(p<0.05).This shows that this method can achieve the purpose of screening strain with high superoxide dismutase activity,and culturing with low concentrations of paraquat can also improve the superoxide dismutase activity of Rhodotorula marina.

Abstract:An analytical method was developed to determine deoxynivalenol content in beer by high performance liquid chromatography in this study.Separations were achieved on a Zorbax Eclipose XDB-C18(4.6 mm×250 mm,5 μm)in a linear gradient,and the mobile phase was a mixture of methanol and water with phosphoric acid(0.05%,v/v)at(20︰80,v/v.In addition,the column temperature was maintained at 30 ℃ with a flow rate of 1.0 mL/min.The detection wave length was set at 210 nm.There was a good linear relationship between 0.75 mg/L-100 mg/L(R2=0.999 3).The average recovery was between 85.36%~96.92%,and RSD was 4.21%.It was proved to be a convenient and accurate method for analyzing deoxynivalenol content in beer.

Abstract:The objective of this study is to produce a probiotic fermented soymilk with the aim of shortening the fermentation time.For this,soymilk was fermented with probiotic culture AST and yoghurt culture TLB at 42 ℃,during the fermentation and storage of the fermented soymilk(28 days at 4 ℃,the changes in pH-value and viable cells count were observed.Fermentation time significantly reduces to 8 h at 42 ℃ with AST culture(Lactobacillus acidophilus,Bifidobacterium spp.,and Streptococcus thermophilus).However,Lactobacillus acidophilus survived poorly during cold storage and the viable cells count was under the probiotic minimum as soon as after the first week of storage.Soymilk was fermented at 42 ℃ with TLB culture(Streptococcus thermophilus,Lactobacillus bulgaricus,Bifidobacterium animalis subsp.lactis Bb12).Consequently,the fermentation time was shortened to 4 hours whereby the viable cells count of bifidobacteria increased during fermentation for the half of the logarithm scale approximately.During 28 days of cold storage,bacterial count remained over 107 cfu/mL.