超声辅助酶解制备草鱼鳞胶原肽及其理化特性评价

以草鱼鳞为原料，基于研究室原有工艺条件，在酶解过程中施加超声，研究超声功率（0?600 W）和超声时间（0?40 min）对胶原肽得率及理化特性的影响。结果表明，超声对产物得率影响显著。单酶酶解使用碱性蛋白酶、复合蛋白酶、中性蛋白酶。超声条件增加，水解度和氮收率先升高后降低；在碱性蛋白酶酶解时施加300 W、20 min超声，水解度从5.37%升到7.27%；分步酶解使用碱性蛋白酶和风味酶，在每步酶解各施加300 W、10 min超声时，水解度从9.26%升到11.05%。超声对产物分子量和氨基酸含量有一定影响，产物分子量集中在500 u~1 ku，单酶酶解胶原肽在该段分布从24.26%升至33.99%，分步酶解胶原肽在该段分布从31.99%升至39.28%；单酶酶解氨基酸含量从66.30 g/100 g升至73.75 g/100 g；分步酶解从66.05 g/100 g升至70.70 g/100 g。超声对产物乳化性、起泡性和泡沫稳定性影响显著。综上，单酶酶解最佳工艺为碱性蛋白酶酶解中施加300 W、20 min超声；分步酶解最佳工艺为在每步酶解中各施加功率300 W、时间10 min的超声。

Grass Carp Scale Collagen Peptide Preparation by Ultrasound-assisted Enzymatic Hydrolysis and Their Physicochemical Property Evaluation

Collagen peptides were extracted from grass carp scales by ultrasound-assisted enzymatic hydrolysis to explore the effects of ultrasonic power (0~600 W) and duration (0~40 min) on the yield, degree of hydrolysis, and physicochemical properties of the collagen peptides obtained. Alkaline proteinase, compound proteinase, and neutral protease were used during single-enzyme enzymatic hydrolysis. Ultrasound treatment significantly influenced the yield. However, the degree of hydrolysis and nitrogen yield initially increased and then decreased upon ultrasound application. In particular, 300 W ultrasound treatment for 20 min during alkaline protease-mediated hydrolysis increased the degree of hydrolysis from 5.37% to 7.27%. In addition, a 10 min 300 W ultrasound treatment during step-wise enzymatic hydrolysis with alkaline protease and flavourzyme, increased the degree of hydrolysis from 9.26% to 11.05%. Ultrasound also influences the molecular weight distribution and amino acid composition of the products. The molecular weight of the products was mainly within 500 and 1000 u. The content of collagen peptides extracted by single-enzyme enzymatic hydrolysis increased from 24.26% to 33.99%, while the content of collagen peptides prepared by step-by-step enzymolysis increased from 31.99% to 39.28%. Meanwhile, the amino acid content of products from single-enzyme enzymatic hydrolysis and step-by-step enzymolysis increased from 66.30 g/100 g to 73.75 g/100 g and 66.05 g/100 g to 70.70 g/100 g, respectively. Furthermore, ultrasound treatment also significantly affected the emulsification performance, foaming capability, and foam stability of the products. To sum up, single-enzyme hydrolysis can be optimized by 20 min 300 W ultrasound treatment during alkaline protease hydrolysis, while step-by-step enzymolysis can be optimized by 10 min 300 W ultrasound treatment during alkaline protease hydrolysis and another 10 min 300 W treatment during flavourzyme hydrolysis.