不同种类植物多酚对冷藏牦牛肉糜肌原纤维蛋白氧化特性、功能特性及结构的影响

Effects of different plant polyphenols on MP oxidation characteristics,functional characteristics and structure of refrigerated yak mince

植物多酚是天然抗氧化剂,其作为食品添加剂发挥着良好的抗氧化效果。为了探究不同种类植物多酚对冷藏牦牛肉糜功能特性的影响,该文以牦牛肉背最长肌为试验对象,将不同种类的植物多酚(茶多酚、儿茶素、姜黄素、葡萄多酚)添加到牦牛肉糜中,使其在4℃冷藏1、3、5、7、9 d,测定肌原纤维蛋白(myofibrillar protein,MP)的氧化特性、功能特性和蛋白结构等。结果表明,与空白组对比,植物多酚能够通过降低MP表面疏水性和蛋白溶解度抑制羰基和二聚酪氨酸的形成,降低α-螺旋损失,提高巯基的含量和MP的乳化活性和乳化稳定性。同时,在5 d时姜黄素的表面疏水性最低,为23.15,葡萄多酚对MP总羰基含量的抑制效果最佳,在1 d和3 d时,葡萄多酚组的羰基含量显著低于空白组(P<0.05),分别为32.46和26.05 nmol/mg,姜黄素和葡萄多酚对降低MP的溶解性效果极佳,在1 d时姜黄素的蛋白溶解度最低,为4.87%;葡萄多酚能够显著提高MP的乳化活性(P<0.05),且最有利于MP的乳化稳定性。

Plant polyphenols are natural antioxidants,which exert good antioxidant effects as food additives.To investigate the effects of different kinds of plant polyphenols on the functional properties of frozen yak mince,this paper took the longest muscle of yak meat as the test object,and added different kinds of plant polyphenols(tea polyphenols,catechins,curcuminoids,and grape polyphenols)to yak mince,and then refrigerated the mince for 1,3,5,7,9 days at 4℃,and measured the oxidative properties,functional properties,and protein structure of the myofibrillar protein(MP),and the oxidative properties,functional properties,and protein structure of the MP.MP was measured for its oxidative properties,functional properties,and protein structure.Results showed that the plant polyphenols were able to inhibit the formation of carbonyl groups and dimerised tyrosine by reducing the hydrophobicity and proteolysis of the MP surface,to reduce the loss ofα-helix,and to increase the content of sulfhydryl groups as well as the emulsification activity and emulsion stability of the MP,when compared with that of the blank group.Meanwhile,curcumin had the lowest surface hydrophobicity of 23.15 at 5 days.Grape polyphenols had the best inhibitory effect on the total carbonyl content of MP,and the carbonyl content of the grape polyphenol group was significantly lower than that of the blank group(P<0.05)at 1 day and 3 days.The carbonyl content of the grape polyphenol group was 32.46 nmol/mg and 26.05 nmol/mg curcumin and grape polyphenols were extremely effective in reducing the solubility of MP,respectively.Curcumin had the lowest protein solubility of 4.87%in 1 day.Grape polyphenols were able to significantly increase the emulsification activity of MP(P<0.05)and were most favourable to the emulsification stability of MP.