甲鱼蛋蛋白水解物的体外消化及对抗氧化和α-葡萄糖苷酶抑制活性的影响

The Digestion Characteristic of Protein Hydrolysate of Soft-shelled Turtle Egg and Its Effects on Antioxidative and α-Glucosidase Inhibitory Activities

抗氧化及抑制α-葡萄糖苷酶活性是糖尿病防治的有效策略。用木瓜蛋白酶水解甲鱼蛋蛋白,采用超滤法分离小分子质量水解物组分(<2.5 ku);采用体外模拟胃及胃肠道消化模型,探究分子质量<2.5 ku组分的体外消化特性及抗氧化与α-葡萄糖苷酶抑制活性的变化。结果表明:制备的甲鱼蛋分子质量<2.5 ku组分具有良好的色泽(黄绿色),水溶液无色透明。经胃消化,分子质量<2.5 u组分的色谱峰变化不大,表明其在胃中的稳定性较好。而经胃肠道消化,原来的色谱峰降低,有些峰甚至消失,形成了新的色谱峰,肽含量显著升高,表明分子质量<2.5 ku组分中的部分活性肽被胃肠道消化产生更短的肽。分子质量<2.5 ku组分的原液及其胃消化产物和胃肠消化产物的DPPH自由基清除率的IC值(mg/mL)分别是13.61,6.79,3.56;ABTS自由基清除率的IC值(mg/mL)分别是18.21,179.40,>300;α-葡萄糖苷酶抑制率的IC值(mg/mL)分别是17.96,10.81,<1。甲鱼蛋<2.5 ku组分具有潜在的降血糖作用,经胃肠消化后产物仍具有较强甚至更好的降血糖潜力。

Antioxidant intervention and inhibition of α-glucosidase activity are the effective strategies for prevention and treatment of diabetes. In this study, protein of soft-shelled turtle egg was hydrolyzed by papain, and hydrolysate fraction(HF) with low molecular weight < 2.5 ku was separated by ultrafiltration. The digestive characteristic of HF and changes of antioxidative and α-glucosidase inhibitory activities were investigated using in vitro simulated gastrointestinal digestion model. The results showed that the HF had a good color(yellowish green), and its aqueous solution was colorless and transparent. The chromatographic peaks of HF were slightly altered after gastric digestion, indicating that it had a good stability in stomach. However, the original chromatographic peaks were decreased after gastrointestinal digestion, and even some peaks were disappeared. Novel chromatographic peaks were correspondingly formed, and the peptide contents were also increased, indicating that some bioactive peptides in HF were digested to produce shorter peptides. The ICvalues(mg/mL) of DPPH radical-scavenging activities for HF before digestion and after gastric and gastrointestinal digestions were 13.61, 6.79 and 3.56, respectively. The ICvalues(mg/mL) of ABTS radical-scavenging activities were 18.21,6.79 and 3.56, respectively. The ICvalues(mg/mL) of α-glucosidase inhibitory activities were 17.96, 10.81 and < 1,respectively. Therefore, HF with low molecular weight < 2.5 ku of soft-shelled turtle egg has a potential hypoglycemic effect, and its products still has a strong or even better hypoglycemic potential after gastrointestinal digestion.