超高压联合乳酸钙处理对牦牛肉品质及肌红蛋白消化特性的影响

Effects of ultra-high pressure combined with calcium lactate treatment on yak quality and myoglobin digestion characteristics

该研究通过测定牦牛肉pH值、肉色、脂质氧化、肌红蛋白含量、剪切力以及肌红蛋白消化率等,并采用动力学模拟方法,测定肌红蛋白与胃蛋白酶的结合稳定性,明确超高压(100~400 MPa,15 min)联合乳酸钙处理对牦牛肉食用品质以及肌红蛋白消化特性的影响。结果表明,在300 MPa压力下,超高压联合乳酸钙处理提高了牛肉的L值和a值,延缓了脂质氧化,显著提高牛肉的嫩度(P<0.05)。肌红蛋白肠道消化率从空白组的44.05%增加到52.28%,胃消化率提高9.16%。分子动力学模拟结果进一步表明,300 MPa高压联合乳酸钙处理后,肌红蛋白-胃蛋白酶结合稳定性提高,疏水相互作用和氢键减弱,显著改变肌红蛋白血红素与胃蛋白酶的相互作用构象,从而提高肌红蛋白的胃肠道消化率。综上,300 MPa超高压联合乳酸钙处理能明显改善牦牛肉的色度、嫩度和脂肪氧化程度,提高肌红蛋白消化率。研究结果可为肌红蛋白消化困难的潜在机制提供参考。

In this study,the binding stability of myoglobin and pepsin was determined by measuring the pH value,meat color,lipid oxidation(TBRAS),myoglobin content,shear force and myoglobin digestibility of yak beef,and the binding stability of myoglobin and pepsin was determined by kinetic simulation method,and the effect of ultra-high pressure(100-400 MPa,15 min)combined with calcium lactate treatment on the edible quality of yak beef and the digestive characteristics of myoglobin was determined.esults showed that under the pressure of 300 MPa,the ultra-high pressure combined with calcium lactate treatment increased the L and a values of beef,delayed lipid oxidation,and significantly improved the tenderness of beef(P<0.05).Myoglobin intestinal digestibility increased from 44.05%in the blank group to 52.28%,and gastric digestibility increased by 9.16%.The molecular dynamics simulation results further showed that after 300 MPa high pressure combined with calcium lactate treatment,the stability of myoglobin-pepsin binding was improved,the hydrophobic interaction and hydrogen bond weakened,which significantly changed the interaction conformation of myoglobin heme and pepsin,thereby improving the gastrointestinal digestibility of myoglobin.In summary,the 300 MPa ultra-high pressure combined with calcium lactate treatment significantly improved the color,tenderness and fat oxidation degree of yak beef,and improved the digestibility of myoglobin.This study provides new insights into the underlying mechanisms of myoglobin digestive difficulties.