响应面实验优化野生大豆可溶性蛋白的提取条件

结合所筛选的关键因素,应用响应面分析法研究了提取液pH值、液料比、提取温度等关键因素对蛋白提取率和浓度的影响,拟合二次多项实验模型,并通过对各变量与响应值的等高图的叠加,结合计算机模拟优化,得到了最佳的综合因素水平,分别为pH 8.5、液料比22.31、温度46.3℃,在此条件下可溶性蛋白的提取率为43.17g/100 g,蛋白浓度为21.57g/L,期望值为68.6%.验证性试验所得相应条件下得蛋白含量为42.22g/100 g±1.92/100 g;蛋白浓度为20.83 g/L±2.05 g/L.     

地木耳蛋白质提取工艺及其稳定性的研究

对地木耳蛋白质的提取工艺及稳定性进行了研究，结果证明地木耳蛋白质可以采用水为溶剂的方法提取，提取最佳条件为pH=9，浓度为3％（w／w），温度为40℃-50℃。提取时间控制在1．5h。2h即可达到较好的收率，蛋白质的收率可达75％。随着pH值的下降，地木耳蛋白质的溶解度也随之下降，pH〈6时蛋白质沉淀明显。地木耳蛋白质的热稳定性较好，加热温度、加热时间均对地木耳蛋白质的稳定性有一定的影响。地木耳蛋白质提取物具有较高的营养价值，可更方便地应用于食品加工业，应用前景广阔。     

条斑紫菜蛋白和多糖提取工艺优化

以条斑紫菜为原料，采用超声辅助提取蛋白和多糖、通过单因素试验和正交试验，确定了最佳的提取工艺条件。     

桑黄(Phellinus linteus)水溶多糖提取技术研究

采用超声波＋复合酶法预处理对Phellinus linteus子实体水溶多糖进行提取，并对提取多糖成分差异进行初步分析。采用超声波技术预处理桑黄子实体，利用正交实验研究了料液比、时间、功率各因素对桑黄多糖得率的影响；在超声波优化结果基础上，进行纤维素酶＋木瓜蛋白酶法处理，研究了纤维素酶用量、处理时间、木瓜蛋白酶用量、处理时间各因素对多糖得率的影响。研究表明：在料液比1：20、超声波（400W、20min）和纤维素酶（0．8％、pH5．5、45℃、60min）、木瓜蛋白酶（2％、pH5．5、50℃、120min）双重预处理条件下，再进行多糖提取，多糖得率最高。研究表明采用超声波＋复合酶法预处理方法提取多糖，与传统的热水提取法相比，极大提高了提取效率，为Phellinus linteus多糖的产业化打下了基础。     

AQUEOUS EXTRACTION OF OIL AND PROTEIN FROM SOYBEAN AND LUPIN: A COMPARATIVE STUDY

This study compares the effects of extrusion pretreatment and protease addition during aqueous extraction processing (AEP) of soybean and lupin flakes. AEP of flakes resulted in the lowest yields of oil (56%), protein (71%) and [cream  +  free oil] (8%) for soybean, while for lupin, yields were 48, 69 and 2%, respectively. AEP protein extraction yields were decreased by extrusion pretreatment, but this pretreatment improved enzymatic action, increasing protein extractability from soybean and lupin by 47 and 26%, respectively. For both protein crops, enzyme-assisted AEP (EAEP) of extruded flakes yielded the highest oil, protein and [cream  +  free oil] yields, which were 96, 85 21%, respectively, for soybean. Yields for lupin were 81, 77 and 10%, respectively. Extrusion followed by enzyme addition positively impacted demulsification yield, the creams from EAEP of soybean and lupin extruded flakes being the less stable toward enzymatic demulsification .

PRACTICAL APPLICATIONS

The vegetable oil industry is looking for alternatives to the traditional solvent extraction of oil-bearing seeds, and there is a need to increase the inefficient conventional aqueous extraction of protein from residual defatted meal, a by-product of the oil extraction process. The concept of enzyme-assisted aqueous extraction processing (EAEP) has been successfully developed for extruded soybean material, but its efficiency on other oil-bearing seeds still needs to be demonstrated. By determining the oil and protein extraction yields recovered during EAEP of extruded lupin flakes, the feasibility of transferring this process from soybean to other oilseeds will be established.     

碱水解法制取玉米蛋白发泡粉及工艺参数的优化

采用玉米麸质粉为主要原料，经酶液化、碱水解、脱色脱臭、蒸发及干燥制得蛋白发泡粉。经正交试验和计算机辅助设计法，确定的优化工艺条件为：滤饼与水质量比为1：2．2，介质的pH值为11．4，水解时间为8．0h，水解温度为115℃，所得产物的蛋白质含量为65．03％，得率达54.2％。     

桑叶叶蛋白提取工艺的研究

对桑树叶蛋白提取条件的优化进行了研究。结果表明，桑树叶蛋白提取的优化工艺条件为：室温下，以水为浸提荆，打浆时间3min，浸提时间4min，料液比1：5（叶片重比浸提剂体积，即g：m1），漫挺剂pH值8．0，絮凝温度75℃，调节提取液pH为5．0、8．0和13．0得到沉淀物，在60℃干燥。该工艺提取桑树鲜叶叶蛋白得率为：5．17％。     

从玉米芯中提取木聚糖工艺条件的优化

通过单因素及正交试验对从玉米芯中提取木聚糖的工艺条件进行了优化，最佳工艺如下：NaOH溶液的浓度为15％，固液比1：20，90℃抽提90min；离心，将上清液pH值调到5．0，静置过夜，离心得到木聚糖A，再将离心液用3倍95％的工业酒精沉淀60min得木聚糖B，在上述条件下木聚糖提取率为28．5％。     

THE EFFECTS OF STORAGE AND HEATING ON LYSINE AVAILABILITY OF FOOD-GRADE PROTEINS FROM PASTURE HERBAGE AS MEASURED BY CHEMICAL, BIOLOGICAL AND MICROBIOLOGICAL ASSAYS

Food-grade protein concentrates isolated from pasture herbage stored and/or heated either alone or with glucose to cause various types of damage to lysine were analyzed for available lysine using chemical procedures and bioassays with chickens, mice, rats and protozoon Tetrahy-mena pyriformis. There were substantial differences in the results obtained with the various chemical methods which showed their different sensitivities to a particular type of lysine damage which had occurred during storage and heat processing. Overall, chemical procedures gave lower values for available lysine than the biological ones, and thus may underestimate availability. The responses of mice and Tetrahymena pyriformis to various types of lysine damage were similar to those observed with chicks, while rats appeared to be less sensitive test animals in detecting the changes in lysine availability in stored or heat processed foods. The necessity to adapt a rapid system for lysine availability determination in foodstuffs and cereal-based diets is discussed with reference to the proper quality control of food-grade proteins, isolated from pasture herbage and subjected to storage or heat processing, before being used in feeding schemes with school children in developing countries. The use of Tetrahymena pyriformis or a simple chemical procedure may provide a built-in safety margin to insure proper quality control of food-grade proteins.     

蚕豆蛋白质提取工艺的研究

探讨蚕豆蛋白质提取影响因素,以单因素和正交试验确定最佳工艺条件.结果表明,蚕豆蛋白质的等电点PI为4.5,提取蚕豆中蛋白质最佳工艺条件为:温度40℃,提取时间2 h,料液比1:5,碱液浓度5×10-5mol/L.