摘要
本文研究了用2709碱性蛋白酶和木瓜蛋白酶顺序水解油菜籽分离蛋白的工艺及条件,探索了双酶水解菜籽分离蛋白H2O2氧化脱色及其乙酸酐改性的方法。实验结果表明:以稀碱提取菜籽分离蛋白,蛋白质收得率73.6%。制备的菜籽分离蛋白呈深褐色,蛋白质含量91.5%,碱甙含量0.024%,植酸含量0.32%。2709碱性蛋白酶和木瓜蛋白酶在50±1℃和55±1℃、pH10.0和pH7.5、E/S(U/g)=5×103条件下水解菜籽分离蛋白60分钟,DH%达到17.15%,其中前者贡献率为59.3%,后者为40.7%。经双酶水解的菜籽分离蛋白等电点仍为pH3.5。双酶水解菜籽分离蛋白在H2O2/蛋白质(V/W)=1.25～1.5、温度≥80℃下进行H2O2氧化脱色,获得淡乳黄色的蛋白,其收得率为94.83%。脱色双酶水解菜籽分离蛋白用30%乙酸酐(V/W)在pH=9.0～9.5、温度20℃下进行乙酰化改性,获得无异味、等电点为pH4.0、清液蛋白含量18.47mg/ml的乙酰化菜籽酶水解分离蛋白。
The technology and condition about sequentially hydrolyzing rapeseed isolated protein by 2709 alkaline proteinase and pawpaw proteinase were studied.Methods that were oxygenizing pigment by H2O2 and modifiying peptide by acetic anhydride in the hydrolyzate were developed.It showed that extraction rate of rapeseed isolated protein was 73.6%while NaOH concentration was 1%,the temperature 60℃and extracting time 5 hours where as in the brown powder.protein content was 91.5%,glucoraphenin 0.024%,and phytic acid 0.32%.The isolated protein was sequentially hydrolyzed by 2709 alkaline proteinase at E/S (U/g)=5×103,50±1℃,pH10.0,60mins and Pawpaw proteinase at E/S(U/g)=5×103 ,55±1℃,pH7.5,60mins.The hydroly sis degree(DH%) was arrived at 17.15%.During the reaction,DH%of 2709 alkaline proteinase was 59.3%,but pawpaw proteinase 40.7%and the isoelectric point remained at pH3.5.The light yellow protein with yield 94.83%was obtained through oxygenizing pigment while the temperature was above 80℃and ratio of H2O2/protein (V/W) from 1.25 to 1.5.Through acid lating reaction alith rate of acetic anhydride to the proteins 30%,the separated protein isoelectric point was pH4.0 and protein concentration in water liquid 18.47mg/ml,but no peculiar smell was found at 20℃and pH9.0～9.5.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2002年第3期33-38,共6页
Food Science
