共查询到20条相似文献,搜索用时 234 毫秒
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目的对仙草多糖碱液提取工艺条件进行优化。方法研究碱提法提取仙草多糖的条件,考察碱浓度、提取温度、提取时间及液料比等因素对仙草多糖得率的影响。在单因素实验的基础上,选取碱浓度、提取时间及液料比3因素应用响应面中Box-Benhnken设计原理进行试验设计,以仙草多糖提取率为响应值,建立多糖提取率的二次回归方程,得到碱液提取多糖的最佳条件。结果仙草多糖提取的最佳浸提条件:Na HCO_3 1.25%,提取时间3h,液料比35:1(V:m),在此条件下仙草多糖提取率为8.10%。结论碱液提取法能够提高仙草多糖的提取率。 相似文献
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为了研究饲料中玉米蛋白粉对黄颡鱼生长性能、部分生理功能的影响,以初均重(13.82±1.06)g的黄颡鱼为试验对象,以使用挤压膨化日粮在等氮、等能、等磷条件下,将饲料中玉米蛋白粉用量设置0%、6%、10%、14%,以及叶黄素添加对照组共5个试验组,每组3个平行。在池塘网箱中饲养58 d,结果显示,不同饲料组黄颡鱼的成活率、饲料系数、特定生长率、增重率、蛋白效率差异不显著(P0.05);各组别黄颡鱼的脏体长、肝体比、肥满度和鱼体营养组成等差异不显著(P0.05);对黄颡鱼的血脂含量、非特异免疫力、肝胰脏功能等无显著性影响(P0.05),而对血糖含量则产生显著性影响(P0.05)。在黄颡鱼挤压膨化饲料中可以使用6%的玉米蛋白粉,能够维持黄颡鱼的正常生产性能和正常生理功能。 相似文献
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双螺杆挤出改性处理脱脂玉米蛋白粉。以脱脂玉米蛋白粉含水量、挤出温度、螺杆转速为响应因素,可溶性蛋白含量为响应值,采用响应面分析方法,确定脱脂玉米蛋白粉挤出改性的最佳工艺条件。结果表明:物料含水量68%、挤出温度163℃、螺杆转速30Hz(225r/min)时,挤出脱脂玉米蛋白粉中可溶性蛋白含量最高,为3.43%。采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)测定挤出改性后玉米可溶性蛋白的分子质量分布,结果显示其分子质量介于3500~14300D之间,且主要是分子质量为3500~6500D的多肽。改性后的玉米蛋白粉其理化性质都有了较明显的改善,说明双螺杆挤出改性玉米蛋白粉效果明显,切实可行。 相似文献
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Investigation of Cornmeal Components Using Dynamic Vapor Sorption and Differential Scanning Calorimetry 总被引:2,自引:0,他引:2
Degermed cornmeal, native starch, and corn gluten meal were individually extruded. DVS technology was used to produce isotherms and to condition extrudates to a constant moisture for Tg analysis. The DVS method results are compared to a PEC method. DSC was used to determine Tg. Isotherm and Tg data for starch and corn gluten meal were used to predict cornmeal snack sorption and Tg behavior. The Tg for extruded cornmeal, dent starch, and corn gluten meal at 18.5%db moisture content were 46.2, 49.4, and 12.7 °C, respectively. This suggests that the polymeric fractions of cornmeal (starch, protein) contribute to the Tg of cornmeal approximately based on the weight fraction of each polymer. 相似文献
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《Journal of dairy science》1987,70(4):814-822
Holstein cows in early lactation were used to compare three combinations of extruded whole soybeans and corn gluten meal to soybean meal. Treatments were (as a percentage of supplemental crude protein) 100% soybean meal; 75% whole soybeans extruded at 149°C, 25% corn gluten meal; 50% extruded soybeans, 50% corn gluten meal; and 25% extruded soybeans, 75% corn gluten meal. Diets were formulated to be 37.5% corn silage, 12.5% alfalfa cubes, and 50% concentrate (dry matter). Dietary crude protein was 15.7% of dry matter, and supplemental protein sources supplied 27% of total dietary protein. Diets were fed as total mixed rations and data were collected from 4 to 116 d postpartum.Milk and fat-corrected milk yields ranged from 31.0 to 34.3 and from 29.3 to 33.3 kg/d, respectively, and were greater for cows fed soybean meal than those cows fed 75 or 50% of their supplemental protein as extruded soybeans. Milk yield of cows consuming 75% of their supplemental protein from corn gluten meal was similar to all other treatments. Ruminal ammonia concentrations were lower in cows fed extruded soybeans and corn gluten meal compared with those fed soybean meal and ranged from 9.1 to 12.4mg/100 ml. Total volatile fatty acid concentration and pH did not differ among treatments. Combinations of extruded soybeans and corn gluten meal were not advantageous compared with soybean meal as a supplemental protein source for lactating cows in this experiment. 相似文献
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为了改善谷朊粉在水溶液中的物化性能,利用碱性蛋白酶对谷朊粉进行了有限水解。通过单因素实验,分析了底物浓度、反应温度、加酶量和反应时间对其分散稳定性、胶黏性的影响,并分析了酶解物中的蛋白质分子粒径。通过正交实验确定了以提高谷朊粉分散特性和胶黏性为目的的最佳酶解条件为:底物浓度0.30g/mL、温度50℃、加酶量0.50%、反应时间20min,此时可使谷朊粉的相对分散稳定性达到96.3%,黏度为3.2mPa.s,蛋白质平均分子粒径604.6nm。分析显示,不同酶解样品分散稳定性、黏度和蛋白质平均分子粒径三种指标之间的变化趋势并不完全一致。 相似文献