NO-AMPK通路对牛肉宰后成熟过程中蛋白特性与肉品质的影响

为研究宰后NO-AMPK通路对牛肉蛋白特性及肉品质的影响,以一氧化氮合成酶(NOS)抑制剂L-NAME、一磷酸腺苷活化蛋白激酶(AMPK)抑制剂Compound C处理的牛臀股四头肌为研究对象,生理盐水处理作为对照,将肉样与处理液在4℃条件下1:1(g:mL)混合浸泡12 h后,在成熟0、6、12、24、48、72、120 h测定肉样的蛋白功能特性、保水性、嫩度以及肌肉组织结构等相关指标。结果显示,L-NAME组中一氧化氮NO含量在6~72 h显著低于对照组(P<0.05);3组中AMPK活性先增大后减小,L-NAME组和Compound C组中AMPK活性在6 h分别比对照组降低14.78%和26.75%;L-NAME组中总蛋白溶解性在6、24 h低于Compound C组,高于对照组(P<0.05),表面疏水性在12、48 h显著低于对照组(P<0.05)并高于Compound C组;L-NAME组中剪切力仅在48 h显著高于对照组并低于Compound C组(P<0.05);对照组中肉样蒸煮损失最大,Compound C组中肉样蒸煮损失最小。以上结果表明,牛肉宰后成熟过程中,NO能够通过AMPK通路改善牛肉嫩度,但对其保水性产生了不利影响。本研究结果可为牛肉宰后能量代谢及肉品质控制相关研究提供一定的理论基础。

The Effect of NO-AMPK Pathway on the Protein Characteristics and Meat Quality of Beef During Postmortem Maturation

In order to study the effect of NO-AMPK pathway on beef protein properties and meat qualities during postmortem, gluteal quadriceps were treated with nitric oxide synthase (NOS) inhibitor L-NAME, adenosine monophosphate-activated protein kinase (AMPK) inhibitor Compound C, and saline treatment was used as the control. The meat samples were mixed with the treatment solution at 4℃ with a ratio of 1:1 (g:mL) and soaked for 12 h. Protein functional properties, water retention, tenderness, muscle tissue structure and other related indicators were determined at 0 h, 6 h, 12 h, 24 h, 48 h, 72 h, 120 h. The results showed that the NO content in the L-NAME group was significantly lower than that in the control group at 6~72 h (P<0.05). The AMPK activity in the L-NAME group and Compound C group was 14.78% and 26.75% lower than that in the control group at 6 h, respectively. Total protein solubility in L-NAME group was lower than that in Compound C group and higher than that in control group at 6 and 24 h (P<0.05), the surface hydrophobicity was significantly lower than that in control group at 12 and 48 h (P<0.05) and higher than that in Compound C group; The shear force in L-NAME group was significantly higher than that in control group and lower than that in Compound C group only at 48 h (P<0.05). The cooking loss was the highest in the control group and the lowest in the Compound C group. The above results indicated that NO could improve beef tenderness through the AMPK pathway during post-mortem beef maturation, but it had an adverse effect on the water retention. The results of this study can provide a theoretical reference for the post-mortem energy metabolism and meat quality control of beef.