【摘要】 以罗非鱼(Tilapia zillii)鱼鳞为原料,考察提取pH和温度对明胶蛋白组分及其性质的影响。结果表明,鱼鳞明胶蛋白在浸提pH大于5时容易发生酶解,pH小于3时会发生热降解,而在pH 4下酶解和热降解均被有效抑制。在pH 4下利用40℃浸提明胶时,蛋白的提取率只有1.84%,提取的明胶中亚氨基酸比例低而钙、磷、钠、镁等矿物质含量高,因而无法形成凝胶和蛋白膜。当浸提温度提高到50℃及以上时,明胶提取率大幅增加,明胶中亚氨基酸比例上升且矿物质含量比例下降。另外,在pH 4、70℃下浸提的明胶其凝胶强度可达283g,可形成机械强度为50MPa的蛋白膜,表明该条件提取的鱼鳞明胶具有替代哺乳动物明胶的潜力。更多还原

【Abstract】 The effects of pH and temperature on extraction of gelatin from tilapia(Tilapia zillii) scales were investi- gated. The results show that at pH>5, enzymatic degradation of gelatin took place, while at pH<3, acidic thermal hydroly- sis would occur. At pH 4, both the enzymatic degradation and thermal acid hydrolysis could be prevented regardless of temperature. At 40℃, the gelatin yield was low(1.84%), along with low content of imino acid, high content of mineral components such as calcium, phosphorus, sodium and magnesium, which prevented gel or film from formation. At 50℃, the protein yield and imino acid content substantially increased, and mineral content decreased too. Texture profile analysis revealed optimal conditions for producing best gelatin: pH 4 at 70℃, under which the gel strength was 283g and film ten- sile strength was 50MPa, providing potential substitution for mammalian gelatin.更多还原