草鱼鱼鳞胶原蛋白的凝胶性能研究

以草鱼鱼鳞为原料,分别提取鱼鳞中的酸溶性胶原蛋白(ASC)和酶溶性胶原蛋白(PSC),利用动态流变仪和物性分析仪开展胶原凝胶形成和凝胶性能的相关研究,并与哺乳动物来源的猪皮胶原(PC)相比较。实验结果表明,制备所得的3种胶原蛋白均为典型的Ⅰ型胶原并具有完整的3螺旋结构;蛋白浓度和体系pH值是影响胶原凝胶形成的重要因素。ASC形成凝胶的临界pH值为4.5,而PSC和PC为5,3种胶原蛋白凝胶形成的临界蛋白浓度均为0.5mg/mL。粘弹性分析和质构分析的实验结果表明,ASC容易形成一种硬度高但脆性大的凝胶,升高温度可导致其凝胶结构发生不可逆的破坏,而PSC和PC更容易形成一种硬度小但韧性好的凝胶,在低于蛋白变性温度的条件下升高温度可以有效提高凝胶硬度;胶原蛋白凝胶质构受蛋白浓度、体系pH值和蛋白的3螺旋结构影响。蛋白浓度越高,体系pH值越接近中性,形成的凝胶硬度越大,但脆性也随之增加;当胶原蛋白因受热而导致其三螺旋结构破坏后,其凝胶形成能力急剧下降。

The gel properties of collagen from scale of grass carp

In this study,the acid-soluble collagen(ASC) and pepsin-soluble collagen(PSC) were extracted from scale of grass carp by methods of acid and acid-pepsin.The properties of collagen gel were analyzed and compared with pig collagen(PC) by use of rheometer and texture analyzer.The results indicate that the ASC,PSC and PC were type Ⅰcollagen and the triple helical structure well held in the three collagen samples.The collagen concentration and pH were important influencing factors in the gel formation.The critical pH for gelation of ASC is 4.5 but the PSC and PC are 5,the critical concentration for gelation of the ASC,PSC and PC are 0.5mg/mL.The viscoelastic and texture analysis indicate that the ASC gel is rigid and brittle,but the PSC and PC gel are soft and flexile.Increasing temperature would result in irreversible destroyed for ASC gel texture,but enhance the PSC and PC gel rigidity.The texture of collagen gels were influenced by collagen concentration,pH and the triple helical structure of collagen.The rigidity of collagen gel would increase when enhance the collagen concentration and pH.The gelling ability of collagen would reduce rapidly when the triple helical structure of collagen was destroyed.