燕麦肽的制备、抗氧化性及其对α-淀粉酶抑制作用的研究

Study on preparation of oat peptides and its antioxidant activity and inhibition to α-amylase

采用酶法制备燕麦肽,并对其抗氧化性及α-淀粉酶抑制作用进行了研究。在单因素分析的基础上采用正交实验分析方法对燕麦肽水解条件进行优化,测定其抗氧化性;对超滤分离后的两种燕麦肽组分的α-淀粉酶抑制作用进行比较;选用<5ku的燕麦肽通过单因素分析对α-淀粉酶抑制作用条件进行优化。结果表明,燕麦肽的最优水解条件为pH7.5,料液比1∶14,温度60℃,加酶量6%,此条件下燕麦肽DPPH清除率可达到80.11%,1.8mg/mL燕麦肽对Fe2+的螯合能力达到60.24%,3.2mg/mL燕麦肽对羟自由基清除率达到49.15%;5mg/mL小于5ku燕麦肽组分对α-淀粉酶的抑制率为68.98%,5mg/mL大于5ku燕麦肽组分对α-淀粉酶的抑制率为51.06%,小于5ku燕麦肽生物活性较强;燕麦肽对α-淀粉酶抑制作用的最优条件为底物浓度90mg/mL,多肽浓度12mg/mL,抑制时间为10min。燕麦肽具有较好的抗氧化性和α-淀粉酶抑制作用,在开发功能性食品方面具有较大的应用价值。

The extraction of peptides from oat and its antioxidant property and inhibition to a-amylase were investigated. Based on the single factor experiments,the orthogonal design was used to optimize hydrolytic condition. The results showed that optimization hydrolytic conditions were as follows：pH7.5,solid-liquid ratio 1： 14,temperature 60℃,and adding amount of enzyme 6% ,from which the DPPH scavenging rate was 80.11%, Fe2＋ chelating ability of 1.8mg/mL oat peptides was 60.24%,and hydroxyl radical （.OH） scavenging rate of 3.2mg/mL oats peptides was 49.15%. The a-amylase inhibition activity of two fractions obtained from ultrafiltration were compared and the results showed that the a-amylase inhibition activity of 5mg/mL〉5ku oat peptide and 5mg/mL〈5ku oat peptide were 51.06% and 68.98%. The optimized a-amylase inhibition conditions were as follows：concentration of substratum 90mg/mL,concentration of peptides 12mg/mL,inhibitive time 10min. The antioxidant and a-amylase inhibition activities of oat peptides make it suitable for development of functional food.