Characterization of partially purified milk-clotting enzyme from sunflower (Helianthus annuus) seeds.
Characterization of partially purified milk-clotting enzyme from sunflower (Helianthus annuus) seeds.
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DOI：
10.1002/fsn3.338
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发表时间：
2016-09
影响因子：
3.9
通讯作者：
Hamid, Omer I. A.
中科院分区：
文献类型：
--
作者：
Nasr, Assia I. A. M.;Ahmed, Isam A. Mohamed;Hamid, Omer I. A.
关键词：
本研究旨在从葵花籽中提取凝乳酶，并探讨其在利用奶牛和山羊奶生产白色软质干酪方面的潜力。用两种不同的缓冲液混合和提取种子，并评价其凝乳和蛋白分解活性。用硫酸铵分级分离技术对该酶进行了部分纯化。结果表明，葵花籽用5%氯化钠溶液在50℃、pH 5.0的L/醋酸盐缓冲液中提取的凝乳活性最高，凝乳时间最短。饱和度为30~50%的硫酸铵对该酶的纯化倍数为4.3倍，相对分子质量浓度为241.0 U/mL，最终酶得率为10.9%。用SDS-PAGE对部分纯化的酶进行了鉴定，显示两条相对分子质量分别为120和62 kDa的条带。与其他植物酶相比，部分纯化的向日葵酶具有较高的凝乳活性和较低的蛋白水解酶活性。乳源和酶种类对干酪产量和凝乳形成时间均有显著影响。与商业凝乳酶相比，用向日葵酶制作的牛奶干酪的得率更高，而用山羊奶制作的奶酪则相反。
This study was aimed to extract milk‐clotting enzyme from sunflower seeds and to determine its potentiality for manufacturing white soft cheese from cows and goats milk. The seeds were blended and extracted using two types of buffers and milk‐clotting and proteolytic activities were evaluated. The enzyme was partially purified using ammonium sulfate fractionation techniques. Results indicated that sunflower seeds extracted with 5% NaCl in 50 mmol/L acetate buffer, pH 5.0, had the highest milk‐clotting activity (MCA) and lowest coagulation time compared to that extracted with only acetate buffer (pH 5.0). Ammonium sulfate at 30–50% saturation purified the enzyme to 4.3 folds with MCA of 241.0 U/mL and final enzyme yield of 10.9%. The partially purified enzyme was characterized by SDS–PAGE that showed two bands with molecular weight of 120 and 62 kDa. When compared with other plant enzymes, the partially purified sunflower enzyme was found to have higher milk‐clotting activity and lower proteolytic activity. Also, both milk sources and enzyme types significantly affected the cheese yield and curd formation time. The cheese made from cow milk using sunflower enzyme had higher yield compared to that obtained using commercial rennet, whereas the opposite was observed when using goat milk.
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影响因子：
8.8
作者：
Kumari, Moni;Sharma, Anurag;Jagannadham, M. V.
通讯作者：
Jagannadham, M. V.
影响因子：
3.5
作者：
USTUNOL, Z;BROWN, RJ
通讯作者：
BROWN, RJ
影响因子：
6
作者：
Ahmed, Isam A. Mohamed;Babiker, Elfadil E.;Mori, Nobuhiro
通讯作者：
Mori, Nobuhiro
影响因子：
6
作者：
Elsamani, Mohamed O.;Habbani, Siddig S.;Ahmed, Isam A. Mohamed
通讯作者：
Ahmed, Isam A. Mohamed
影响因子：
2.9
作者：
BRADFORD, MM
通讯作者：
BRADFORD, MM