Abstract:Antifreeze proteins have special functions and characteristics of thermal hysteresis.They can lower the freezing point,inhibit ice growing and recrystallization,and modify ice morphology.The article reviewed the recent advance in antifreeze protein,and introduced its types,structure properties,functional characteristics and antifreeze mechanisms as well as their applications and prospect in food industry.

Abstract:In this study,butanol production from corn stover hydrolyzate by Clostridium saccharobutylicum DSM 13864 was investigated.The medium composition was optimized by orthogonal method as follows:CaCO3 2.0 g/L,(NH4)2SO4 1.0 g/L,K2HPO4 0.5 g/L,corn steep powder 15 g/L,and MnSO4·H2O 0.01 g/L.In a 3 L bioreactor,total solvent of 16.1 g/L(butanol 10.59 g/L) was reached after 40 h of fermentation,and the productivity and yield were 0.40 g/(L·h) and 0.33 g/g,respectively.Batch fermentation process using temperature-shifting demonstrates that lower temperature is beneficial to the solvent accumulation.Compared with temperature-constant process(37 ℃),total solvent was increased from 17.01 g/L to 19.98 g/L.The temperature-shifting continuous fermentation process was operated for 269 h at dilution rate of 0.1 h-1,and the solvent production entered a stable phase at around 80 h.The average solvent during the stable solvent-production stage is 12.28 g/L(including 8.50 g/L butanol),and the average solvent productivity is 1.23 g/(L·h),representing 4.92 times of temperature-shifting batch fermentation(D).

Abstract:This study aims to establish the cell injury and apoptosis model of human dermal fibroblasts induced by hydrogen peroxide in vitro and investigate the protective effects of several Chinese herbs on hydrogen peroxide-induced oxidative stress injury.The viability of human dermal fibroblasts was measured with MTT chromatometry,then the morphological changes of cells were observed through Hoechst 33342 staining and the apoptotic cells were detected by TUNEL assay.The results showed that normal human dermal fibroblasts were damaged by hydrogen peroxide at a appropriate concentration(0.8 mmol/l) for 6 h.The results also indicated that Chinese herbs increased obviously the cell viability and decreased the apoptosis rate.It was concluded that Chinese herbs could protect human dermal fibroblasts from hydrogen peroxide-induced oxidative stress injury.

Abstract:Beer foam proteins play important roles on beer foam quality.In this study,the secondary structure of beer foam proteins and malt proteins were investigated by Circular Dichroism spectroscopy,and SDS-PAGE pre-fractionation combined with LC-MS/MS was applied to achieve more comprehensive proteome profiles of beer foam proteins.It was indicated that malt proteins mainly existed in α-helix form,while beer foam proteins mainly existed in β-sheet and random coil structure,not showing the typical α-helix structure.The structure characteristic of foam proteins had the advantage to the surface hydrophobic,so as to the beer foam stability.Beer protein bands were positively identified and categorized into 11 protein species,which included protein Z4,LTP1,BDAI-1,and some proteinase inhibitors and trace amount hordein fragments.

Abstract:The effect of electron beam(EB) irradiation on instant chicken feet was examined,and the qualities of the instant chicken feet treated at different doses were analyzed in terms of thiobarbituric acid reactive substances(TBARS),Total Volatile Basic Nitrogen(TVB-N),flexibility,juice loss rate,sensory quality and total bacterial count.The results showed that instant chicken feet treated with dose of 6.0 kGy,and stored for 180 days,the total bacterial count of chicken feet was 4 300 cfu/g and the D10 value of colony number was determined to be 1.84-2.22 kGy.There was significant difference in TBARS value between irradiation and non-irradiation when the doses of EB irradiation were upon 6.0 kGy,while there was no significant difference in TVB-N,and there was no there was no significant difference in juice loss rate and flexibility when the dose was less that 8.0 kGy;irradiation had some effects on sensory quality,but the effects were very small.After 180 days of storage at room temperature,the results show that EB irradiation could significantly reduce and control the instant chicken feet microorganism,and its shelf-life could be prolonged.

Abstract:Discoloration of dehydrated lettuce is a very serious problem in the process of storage,this paper is aimed at looking for an effective solution for this question.First,The technology of vacuum microwave was applied to prevent enzymatic reaction.Second,the cationic in the lettuce was conjugated by EDTA-Na.At last,MgAC2、ZnAC2 were used to replace metal irons for protecting the green color.Finally,the optimum condition was determined through orthogonal experiment and the result is as follows: non-enzymatic browning can be well prevented when the pH of the color protecting liquid is 7.5～8.5 with 2% lactose and 2.5% sucrose,and blanching 3 min.The drying condition is 78 ℃ for 2.5 h in the initial stage and 65 ℃ for 3.5 h following.The product should be vacuum-packed and stored in dark environment.

Abstract:The wastewater treatment by Chlorella vuganis under light and dark condition,and by algae-bacterium system under dark condition were studied,the Chlorella vuganis’s sustainable growth under dark condition was also studied.The results showed that the removal of COD under dark condition was better than light condition,but TN&TP were on the contrary.Chlorella vuganis played a key role in removal COD,TN,TP in the mixed system of Chlorella vuganis and activated sludge when stationarily incubated under dark condition.However,activated sludge played a key role in removal COD,TN,TP in the mixed system when shakingly incubated under dark condition.What’s more,the mixture of algae and bacterium couldn’t have an effect on mutualism and improved the efficiency of wastewater treatment,and Chlorella vuganis could grow and treat wastewater sustainably under dark condition.

Abstract:In this paper,the effects of salicylic acid(SA) on paclitaxel metabolism of endophytic fungus from Taxus Chinensis was preliminary studied.SA was added to the fermentation broth with different concentrations at different time.The results showed that SA at 5.0 mg/L can improve the yield of paclitaxel to 604.0 ug/L at the beginning of the stabilization period of the endophytic fungus.And different concentrations of SA can also improve the yield of paclitaxel as the same,while SA at 25 mg/L is the most obvious,the yield can reach to 890.0 ug/L.It’s 1.88 times to the fermentation broth which SA not added.

Abstract:Viable cells of Listeria monocytogenes could be selectively discriminated from dead cells by applying Ethidium bromide monoazide(EMA) cooperated into loop-mediated isothermal amplification(LAMP) assay.The EMA-LAMP method was used for the rapid detection and identification of foodborne pathogene Listeria monocytogenes.The amplification can be obtained in an hour under the isothermal condition at 63°C by designing four LAMP specifically primers from the six different sequences on the hly gene.The EMA-LAMP assay discriminated the viable and dead cells of Listeria monocytogenes.The result showed that the optimized light exposure time to achieve cross-linking of DNA by the EMA in dead cells and to photolyse the free EMA in solution was at least 20 min,and the use of 10 μg/ml or less of EMA did not inhibit the LAMP amplification of DNA derived from viable cells,but the minimum concentration of EMA to completely inhibit the LAMP amplification of DNA derived from dead cells was 4.0 μg/ml;a detection limit of the assay for the viable cells was 20 CFU/ml.

Abstract:Pulsed electric field(PEF) for food sterilization is a process that pulsed voltage is applied to the food product,which is placed between or passed through two electrodes of the treatment chamber.During the process,the electric field strength and the temperature distribution in the treatment chamber are the two key factors affecting the system efficacy and food quality.This paper first developed a 3D model of the co-field treatment chamber,based on which developed a mathematical model of the three coupled fields according to the theory of the electric field,flow field and temperature field,and simulated the flow properties,temperature distribution of the liquid(Nacl solution) and electric field distribution in the treatment chamber under the conditions of pulse voltage V,pulse length τ,frequency f,flow rate v and temperature T.The simulation obtained the relationship between the geometry of the co-field treatment chamber and the temperature,electric field distribution.It also provides an important basis for optimizing the treatment structure and improving the sterilization effect.

Abstract:Ultrasound-assisted extraction of synephrine from citrus dropt fruits by supercritical CO2 was studied in this paper.Then the content of synephrine extracted by ultrasound-assisted supercritical CO2 was compared with synephrine extracted by ethanol and that extracted by supercritical CO2.The result showed that the optimum extraction technique were ultrasound power 250 W,temperature 45 ℃,pressure 20 MPa,CO2 flow rate 9 L/h,modifier 12%,time 4.5 h.Under above conditions the extraction rate could reach 43.9%.The content of synephrine extracted under above conditions was 51.2%,which was higher than that(44.7%) of synephrine extracted by supercritical CO2 and far above that of synephrine(4.6%) extracted by ethanol.

Abstract:Based on the β-glucosidase coding sequences from GeneBank,a β-glucosidase gene was amplified from Aspergillus niger by using RT-PCR and vector pMD-18T-bgl was constructed.The expression vector pPIC9K-bgl was constructed by subcloning the gene into plasmid pPIC9K,and then transformed into P.pastoris GS115 through electroporation after linearized by BglⅡdigestion.The recombinant P.pastoris G115 were screened in MD and YPD/G418 plate.The activity of the engineered strain reached to 38 U/mL after induction with the final concentration of 1% methanol.SDS-PAGE analysis showed that the recombinant P.pastoris GS115 had an additional protein band of approximately 90 kD,which was not present in the control,and consistent with the theoretical value of the gene product.The crude enzyme catalysis results indicated that the optimum temperature and pH for the activity were about 50 ℃ and 5.5,respectively.

Abstract:The effects of different antioxidants on anti-oxidative protection of the mushroom sauce during its conservation were studied by Schaal experiment according to the peroxide value and acid value of mushroom sauce.The result showed that TBHQ was the best to inhibit oxidation in the condition of the same dosage.But antioxidant effect of 0.02%TBHQ was weaker than 0.015%TBHQ and 0.015%TBHQ.Vitamin C or critic acid exhibited great anti-oxidative protection and synergistic effect to the compound of TBHQ and BHT in the mushroom sauce,and Vitamin C was better than critic acid.By adding the compound of 0.015%TBHQ and 0.005%BHT and 0.01% vitamin C to the mushroom sauce,the shelf-life could be prolonged from 256 to 576 days in 20 ℃.

Abstract:The effect of planting area and cultivar on the taste-related compounds of lychee was studied by analyzing the physicochemical indices and electronic tongue for Feizixiao and Huaizhi lychee.Lychee fruits contain three sugars: sucrose,fructose and glucose and eight organic acids: oxalic acid,tartaric acid,malic acid etc.In the same planting area,sweetness of Feizixiao lychee was higher than that of Nuomici lychee.For the Feizixiao lychee,Shenzhen and Qinzhou lychee had the highest TS/TA ratio.For the Huaizhi lychee,Shenzhen lychee had the higjhest TS/TA ratio.The contribution of sucrose to sweetness of Shenzhen Feizixiao was the highest.For all lychee samples,the contribution of fructose to sweetness was higher than that of sucrose and glucose.The electronic tongue map was similar with the map of physicochemical indices and could significant distinguish the lychee samples from different producing area.

Abstract:In this paper the effect of laccase treatment on wood was studied by SEM,DSC,Contact angle measuring instrument.It was found that with the treatment by laccase,the encrusting substances of lignin on the wood surface were removed partly and some pores appeard.As compared with the control wood,Tg of the laccase-treated wood was decreased,the surface of the wood was easier to infiltrate and the water-holding capability was increased.It was thought that these influences were good for the production of wood-based panels.Validation experiments showed that the performance of timber processing was improved.

Abstract:Extrusion cooking has become an important direction of grain processing.Nine kinds of grain were extruded using a twin-screw extruder in the same condition.The physicochemical properties of extruded products,which inlcuded gelatinization degree,water absorption index,water solubility index,expansion ratio,hardness,crispness and bowl life,were studied and comparied.The correlation between the composition of materials and physicochemical properties of products,as well as the correlation between the physical and chemical properties,were studied.

Abstract:During the frozen storage,water loss,protein denaturation,weight and nutrition loss of scallop products was caused.It could bring great economic loss and impede the economic development of local fisheries.Therefore,the development of new scallop products and the study of water holding technology was of great significance.In this paper,the fresh scallop adductor was used as raw materials,and the scallop adductor mince was prepared with the actual production process by adding phosphate,salt and combinations of salt and phosphate.The changes of quality and weight of minced products were studied.Results showed that mixture of salt and phosphate could effectively reduce the loss of cooking and thawing weight,protein water solubility and TVB-N were descended,but protein salt solubility was increased with salt concentration.