牛肉宰后成熟过程中细胞自噬的变化分析  

Changes in Autophagy during Postmortem Aging of Beef

作　　者：李叶 鲁文洁 王海蓉 杨啸吟[1] 刘昀阁 梁荣蓉[1] 毛衍伟[1] 张一敏[1] 朱立贤[1] LI Ye;LU Wenjie;WANG Hairong;YANG Xiaoyin;LIU Yunge;LIANG Rongrong;MAO Yanwei;ZHANG Yimin;ZHU Lixian(National R&D Center for Beef Processing Technology,College of Food Science and Engineering,Shandong Agricultural University,Tai’an 271018,China)

机构地区：[1]山东农业大学食品科学与工程学院,国家牛肉加工技术研发专业中心,山东泰安271018

出　　处：《食品科学》2024年第15期214-221,共8页Food Science

基　　金：国家自然科学基金面上项目(32072239);山东省牛产业技术体系项目(SDAIT-09-09);现代农业产业技术体系建设专项(CARS-37)。

摘　　要：本研究分析宰后牛肉成熟14 d过程中细胞自噬的变化规律及其与牛肉品质间的关系。牛肉宰后成熟过程中,肉色方面,L*值随成熟时间延长而升高,a*值、b*值均呈现先升高后降低的趋势;嫩度随成熟时间延长不断提高,剪切力与肌间线蛋白(Desmin)表达量均呈现下降趋势(P<0.05);保水性随成熟时间的延长而下降,贮藏损失率和蒸煮损失率上升(P<0.05)。进一步对自噬相关蛋白进行研究,牛肉宰后成熟过程中,Beclin-1与微管相关蛋白1轻链3作为细胞自噬发生的标志性蛋白,其表达量均呈先升高后降低的趋势,并在12 h达到最大。调控自噬的AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)-哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)-酵母Atg1同源蛋白激酶(UNC-51 like kinase 1,ULK1)通路作为一条重要的能量代谢通路,在缺血缺氧环境下能够诱导细胞自噬的发生。本研究结果表明,牛肉宰后成熟过程中AMPK、p-AMPKThr172、ULK1的蛋白表达量均呈先升高后降低的趋势,并在12 h达到最大,mTOR表达量则持续下降(P<0.05),说明细胞自噬在宰后0~12 h增强。相关性分析结果显示,宰后自噬相关蛋白表达水平与牛肉的肉色呈负相关,与蒸煮损失、剪切力、Desmin蛋白相对表达量呈正相关(P<0.05)。综上所述,宰后牛肉成熟336h过程中可能通过AMPK-mTOR-ULK1通路激活细胞自噬进而对牛肉品质起到一定的调控作用。In this study,the changes in autophagy and its relationship with beef quality during 14 days of postmortem aging were investigated.In terms of meat color,the L*value increased with aging time,and the a*and b*values increased first and then decreased;the tenderness increased,while the shear force and the expression of desmin decreased(P<0.05).The water-holding capacity decreased during postmortem aging,while the purge loss and cooking loss increased(P<0.05).Further studies on autophagy-related proteins showed that the expression of Beclin-1 and microtubule associated protein 1 light chain 3(LC3),as the markers of autophagy,increased first and then decreased,reaching the maximum at 12 h.AMP-activated protein kinase(AMPK)-mammalian target of rapamycin(mTOR)-yeast Atg1 homolog UNC-51 like kinase 1(ULK1),as an important energy metabolic pathway,activated autophagy in an ischemia and hypoxia environment.During postmortem aging,the protein expressions of AMPK,p-AMPKThr172,and ULK1 all initially increased and subsequently decreased,reaching the maximum at 12 h.The expression of mTOR continuously decreased(P<0.05),suggesting that autophagy was up-regulated from 0 to 12 h postmortem aging.Pearson correlation analysis showed that the expression levels of autophagy-related proteins were negatively correlated with meat color,but positively correlated with water-holding capacity and shear force during postmortem aging process(P<0.05).In summary,autophagy could be activated through the AMPK-mTOR-ULK1 signaling pathway during the 336 h postmortem aging process,thereby regulating beef quality.

关 键 词：牛肉 宰后成熟 细胞自噬 品质 

分 类 号：TS251.1[轻工技术与工程—农产品加工及贮藏工程]