功能栗仁的酶法制备及功能评价

Enzymatic Preparation and Biological Activities of Functional Chinese Chestnut Kernel Products

对完整形态的板栗仁进行酶解,使之含有功能性短肽,以强化或者赋予其保健功能,拟开发出具有降血压和抗氧化活性的功能栗仁产品。主要对功能栗仁制备的关键技术进行研究,包括蛋白酶的选择、酶解条件的优化、酶解后栗仁的功能评价等。结果表明:采用木瓜蛋白酶酶解可得到较高的短肽得率和水解度;木瓜蛋白酶与α-淀粉酶复合可提高短肽得率;木瓜蛋白酶和其他蛋白酶复合可提高水解度,其中与Flowryme复合水解度提高最为明显;蛋白酶用量过低或过高均不利于酶解反应进行;α-淀粉酶(Liquozyme Supra)的适宜用量为0.35g/100mL蛋白酶液,木瓜蛋白酶和Flowryme适宜的配比为2:1(m/m),蛋白酶的适宜用量为8000U/g,当酶解温度55℃、酶解时间15h时,短肽得率为43.62%、水解度为26.27%;板栗水解物具有较好的ACE(血管紧张素转化酶)抑制和抗氧化活性,ACE抑制的IC50为4.70mg/mL,亚油酸氧化抑制的IC50值为4.26mg/mL,清除超氧阴离子自由基、羟自由基和DPPH自由基的IC50值分别为2.77、7.78、4.30mg/mL。

Intact Chinese chestnut kernels were enzymatically hydrolyzed to develop functional products with antihypertensive and antioxidant activities.Enzyme screening was investigated for different purposes.Papain could result in higher short-chain peptide yield and degree of hydrolysis（DH） than other five proteases investigated.A higher short-chain peptide yield was obtained by papain ＋ α-amylase than papain ＋ pullulanase and papain alone.Compared with papain alone,the combination of papain and each of the other five proteases increased the DH of Chinese chestnut kernels,especially in combination with Flowryme.Improper protease amount was unfavorable for the hydrolysis of Chinese chestnut kernels.The appropriate amount of α-amylase was 0.35 g/100 mL hydrolysate.The appropriate ratio of papain to Flowryme was 2：1（m/m）.The DH of Chinese chestnut kernels was 26.27% and the short-chain peptide yield was 43.62% under the following hydrolysis conditions： protease amount of 8000 U/g protein,hydrolysis temperature of 55 ℃ and hydrolysis time of l5 h.The resultant hydrolysate exhibited excellent ACE inhibitory activity with an IC50 of 4.70 mg/mL and antioxidant activity.The IC50 vales for inhibiting linoleic acid oxidation and scavenging superoxide anion,hydroxyl,DPPH free radicals were 4.26,2.77,7.78 mg/mL and 4.30 mg/mL,respectively.