基于同位素标记相对和绝对定量技术研究藏香猪冷鲜肉冰温保鲜分子机制

本研究基于同位素标记相对和绝对定量技术研究冰温-2℃和冷藏4℃条件下,藏香猪冷鲜肉蛋白质组变化及其与微生物指标(菌落总数)、理化品质(总挥发性盐基氮(total volatile base nitrogen,TVB-N)含量、弹性)、蛋白质二级结构(β-折叠和β-转角相对含量)变化的关系.结果 表明:与4℃贮藏条件相比...

Isobaric Tags for Relative and Absolute Quantitation(iTRAQ)-Based Quantitative Proteomics Analysis of the Molecular Mechanism by Which Superchilling Preserves the Quality of Chilled Tibetan Fragrant Pig Meat

Changes in the proteomic profile of chilled Tibetan fragrant pig meat during superchilling(–2℃)and cold(4℃)storage were investigated by isobaric tags for relative and absolute quantitation(iTRAQ),and its relationship with changes in total aerobic count(TAC),physicochemical properties(total volatile base nitrogen(TVB-N)content and elasticity),and protein secondary structures(β-sheet andβ-turn relative content)were evaluated.The results showed a slower rate of changes in TVB-N content,springiness,and the relative contents ofβ-sheet andβ-turn in meat was found during storage for 16 days at–2℃than at 4℃.Proteomic analysis showed that a total of 179 differentially expressed proteins were identified between meats stored at the two temperatures.Among these proteins,143 were found to significantly differ in abundance.In total,97 proteins with differential abundance were found between meats stored at the two temperatures for 0 and 16 days,61 out of which were found to be shared.The differentially expressed proteins mainly included structural proteins,metabolic enzymes,stress proteins and calmodulins.The correlation analysis indicated that myosin,tropomyosin and calpastatin expression level were significantly negatively correlated with TAC,TVB-N content andβ-turn relative content(P<0.05 or P<0.01),and significantly positively correlated with springiness andβ-sheet relative content(P<0.01),while heat shock protein expression level had opposite correlations with the physicochemical properties and protein secondary structures.Therefore,we conclude that superchilling can effectively inhibit the growth of spoilage microorganisms and protein catabolism in pig meat,reduce the changes in TVB-N and protein secondary structure,and maintain elasticity,thereby preserving meat quality.This study provides a reference for in-depth understanding of the molecular mechanism for quality preservation in pig meat by superchilling and exploring reasonable storage conditions.