应用固定化胰蛋白酶制备大豆肽的研究

采用固定化胰蛋白酶水解大豆分离蛋白制备大豆低肽，对固定化胰蛋白酶水解工艺参数等进行了系统研究。结果表明：固定化胰蛋白酶的最适温度为60℃，最适pH为8．7，最佳底物浓度为2．0－3．0mg/mL，大豆分离蛋白的最佳流速为0．3mL/min，大豆分离蛋白的水解率达到45．6％，酶解液中大豆肽含量为1．462mg/mL。酶解液多肽分子量大部分在10000以下。     

不同杀菌温度及贮藏条件对卤蛋菌落总数和脂肪酸组分的影响

本实验以真空包装卤蛋为研究对象,进行95、105 ℃和121 ℃不同温度杀菌,并分别于4 ℃和25 ℃下进行贮藏（121 ℃杀菌仅在25 ℃下贮藏）,测定并分析各样品在贮藏期间内菌落总数和脂肪酸组成的变化。结果表明：各杀菌温度都可在杀菌完成时有效杀灭活体细菌,各组样品菌落总数均小于10 CFU/g;相较于95 ℃杀菌样品,105 ℃和121 ℃杀菌样品的多不饱和脂肪酸总含量分别下降了1.56%和6.83%;随着贮藏时间延长,受杀菌温度、贮存温度、微生物种类、微生物增殖及氧化水解反应等因素的影响,各组样品脂肪酸组成发生差异性变化。95 ℃杀菌、25 ℃贮存的样品仅可保存15 d,且脂肪酸劣变速率最快;105 ℃杀菌、25 ℃贮存的样品可保存75 d,脂肪酸劣变速率较慢;95 ℃杀菌、4 ℃贮存的样品可保存90 d,但脂肪酸劣变速率较快;121 ℃杀菌、25 ℃贮存的样品贮藏90 d时仍未检测到微生物增殖,贮藏期间内脂肪酸总量保留较好,但初始多不饱和脂肪酸水平较低;105 ℃杀菌结合4 ℃贮存的样品在贮藏90 d时同样未检测到微生物增殖,且贮藏期内总脂肪酸保存率最高,可作为生产高营养水平和长保质期卤蛋较好的应用技术。     

固定化猴头菌细胞的研究

利用海藻酸钠对深层发酵的猴头菌细胞进行固定化培养 ,就包埋剂的最佳浓度、发酵条件及固定化猴头菌细胞在深层发酵中应用的可能性进行了探讨。结果表明 ,最佳海藻酸钠的质量分数为 2 % ,CaCl2 质量分数为 2 % ,固定化猴头菌细胞在发酵培养基内的代谢与游离细胞的代谢基本一致 ,发酵液中氨基酸含量最高可达 80 0mg/L ,多糖含量最高可达 14 0 0mg/L ,固定化细胞可以连续使用 3 2～ 48d ,在工业生产中是可行的     

SUPPRESSION OF α-ACETOLACTATE FORMATION IN BREWING WITH IMMOBILIZED YEAST

Immobilized yeast cells extensively produced the diacetyl precursor, α-acetolactate, during alcohol fermentation. The activity of acetohydroxy acid synthetase, which is responsible for the formation of α-acetolactate from pyruvic acid, was high in cell-free extracts of immobilized yeast cells compared with that of free yeast cells. It was suggested that the expression of AHA synthase of immobilized yeast cells was increased during growth in the carrier as compared with free yeast cells. When the initial immobilizing yeast cell concentration was changed from 1.0 × 10⁶ cells/ml to 1.0 × 10⁹ cells/ml, production of α-acetolactate was reduced from 0.94 mg/l to 0.30 mg/l. Furthermore, during continuous fermentation for 10 d, the concentration of α-acetolactate in beer was 0.30 mg/l.     

侗乡糯米酒与朝鲜族米酒的比较研究

对侗乡糯米酒与朝鲜族米酒酒曲制作工艺、生产工艺以及成品酒指标进行了比较研究.结果表明,两者均以糯米为原料采用淋饭法酿制而成,但酒曲制作差异、发酵周期不同导致了各自独特的风格.     

Packaging Effects on Growth of Listeria innocua in Shredded Cabbage

Freshly shredded white cabbage was treated with citric acid and sodium erythorbate, inoculated with Listeria innocua (in lieu of Listeria monocytogenes), and packaged in 230g lots in four types of retail bags with oxygen transmission rates (OTRs) of 5.6, 1,500, 4,000, and 6,000 cc O₂/m²/24 hr, then stored 21 days at 11°C. After 14 days, L. Innocua decreased in cabbage stored in three films. After 21 days, Listeria population increased in all packages, but the increase was less (p<0.05), for cabbage packaged in film with the highest OTR (commercial film).     

固定金属离子亲和膜分离技术：（Ⅱ）研究进展和应用前景

概述了亲和膜及其组件的研究现状以及固定金属离子亲和膜分离技术的研究进展指出了该技术的应用前景．     

Evaluation of immobilized modified lipase: Aqueous preparation and reaction studies in n-hexane

Lipase Saiken 100 (Rhizopus japonicus) and its immobilized form displayed very poor activity (hydrolysis and interesterification) in microaqueous n-hexane solutions. Enzyme modification by the addition of stearic acid or sorbitan monostearate significantly improved activity. A ceramic carrier (SM-10) was used to immobilize modified lipase Saiken (stearic acid, sorbitan monostearate, and lecithin) and was found to further enhance hydrolysis and interesterification rates in n-hexane. In addition, the biocatalysts were re-used for four consecutive batch reactions with no significant shortfall in activity. Reaction rates were also greatly affected by the total reaction water content. Careful control of the biocatalyst water content prior to use and additional reaction water were required to optimize activity and minimize hydrolytic diglyceride byproducts. Hydrolysis and interesterification reaction rates were favored with immobilized biocatalyst water contents of 6.25 and 0.43 wt% with additional reaction water contents of 600 and 20 mg/L, respectively.     

Production of polyhydroxy fatty acids from linoleic acid by Clavibacter sp. ALA2

Hydroxy fatty acids are important industrial materials. We isolated a microbial culture, Clavibacter sp. ALA2, which converts linoleic acid to many polyhydroxy fatty acids. Structures of the products were determined as: 12,13,17-trihydroxy-9(Z)-octadecenoic (THOA, main product), 12-[5-ethyl-2-tetrahydrofuranyl]-7,12-dihydroxy-9(Z)-dodecenoic (ETDDA), and 12-[5-ethyl-2-tetrahydrofuranyl]-12-hydroxy-9(Z)-dodecenoic (ETHDA) acid. The yield of THOA was 25% and the relative amount of the products were THOA/ETDDA/ETHDA =9:1.3:1. The structures of the hydroxy unsaturated fatty acids resemble those of plant self-defense substances.     

Immobilized lipase reactors for modification of fats and oils—A review

This review focuses on the use of immobilized lipase technology to effect hydrolysis, ester synthesis, and interesterification reactions. The various immobilization procedures, reactor configurations, and process considerations are all reviewed and discussed.