Abstract:

Alkaline protease， papain and bromelain were used to hydrolyze cartilage of sturgeon step by step under pH gradient conditions to prepare sturgeon chondroitin sulfate and collagen peptide simultaneous. The effects of enzymatic hydrolysis temperature， enzymatic hydrolysis time， and enzyme dosage on the efficiency of enzymatic hydrolysis were investigated. Based on comprehensive analysis， the optimal temperature for alkaline protease hydrolysis was 45 ℃， hydrolysis time was 2 hours， and enzyme dosage was 100 U·g^-1 cartilage； the optimal temperature for papain hydrolysis was 50 ℃， hydrolysis time was 2 hours， and enzyme dosage was 50 U·g^-1 cartilage； the optimal temperature for bromelain hydrolysis was 50 ℃， hydrolysis time was 2 hours， and enzyme dosage was 30 U·g^-1 cartilage. Sturgeon chondroitin sulfate was extracted at a rate of 85% with a purity of 93%， while collagen peptide was extracted at a rate of 82% with a purity of 90%. In comparison to the currently used domestic production techniques， the multi-enzyme step-by-step enzymatic hydrolysis process established in this study under pH gradient conditions could improve yield and purity， reduce the amount of alkali， and avoid the introduction of organic solvents， thereby lowering the production cost and lessening the burden of environmental pollution.

Key words: enzymatic hydrolysis process, chondroitin sulfate, collagen peptide

摘要：

pH渐变条件下采用碱性蛋白酶、木瓜蛋白酶和菠萝蛋白酶分步连续酶解鲟鱼软骨，同时制备鲟鱼硫酸软骨素和胶原蛋白肽。分别通过温度、酶解时间、酶用量3个单因素实验，研究其对连续酶解效果的影响。综合分析得出最佳条件：碱性蛋白酶酶解温度为45 ℃，酶解时间为2 h，酶用量为100 U·g^-1底物；木瓜蛋白酶的酶解温度为50 ℃，酶解时间为2 h，酶用量为50 U·g^-1底物；菠萝蛋白酶的酶解温度为50 ℃，酶解时间为2 h，酶用量为30 U·g^-1底物。该工艺条件下制备的鲟鱼硫酸软骨素提取率为85%，纯度93%，胶原蛋白肽的提取率为82%，纯度为90%。研究建立的pH渐变条件下多酶分步连续酶解工艺，产率与纯度较国内现有生产方法均有提高，且碱液使用量减少，避免了有机溶剂的引入，从而可以降低生产成本，减轻环境污染负担。

关键词: 酶解工艺, 硫酸软骨素, 胶原蛋白肽