Research On The Effect Of Electromagnetic Field Preservation Technology On Mutton Qualit

China is a nation in traditional sheep breeding and consumption,where lamb has become a popular and healthy food choice due to its high protein,low fat,and low cholesterol content.However,due to its susceptibility to spoilage during processing and storage,there is an urgent need to improve mutton preservation technology to meet the increasing demand for this nutritious food that is rich in a variety of amino acids and trace elements.In this study,the Longissimus thoracis et lumborum of Guizhou White Goat(WG)and Qianbei Ma Goat(QG)were used as research objects.After vacuum packaging,the mutton was stored using electromagnetic field preservation(EP)(-3℃)and frozen storage(FS)(-20℃).During the storage period,physicochemical properties,volatile flavor compounds,and proteomics were examined on days 0 d,15 d,30 d,45 d,and 60 d to investigate the effects of EP and FS methods on the quality of mutton.This study aimed to provide a theoretical and technical foundation for the development and utilization of electromagnetic field preservation technology,as well as the preservation and improvement of mutton quality.The main conclusions were as follows:(1)Chemical methods and high performance liquid chromatography were used to determine the physicochemical indexes and biogenic amines of WG and QG mutton during storage.The results showed that the p H values of the two types of mutton showed dynamic changes between 5.5 and 6.7 under electromagnetic field and frozen storage.At the end of storage,the p H of EP group was higher than that of FS group.Under the two storage methods,the overall L*(Lightness)value showed a downward trend,with both a*(redness)and b*(yellowness)values showing a downward trend first and then an upward trend.Compared to FS group,the cooking loss and shear force of mutton in the EP group were less.For TBARS,TVB-N,and TVC,the changes under EP group were faster than those in the FS group.Spermine and spermidine have a small range of changes under the two storage methods.Histamine,putrescine,cadaverine,and tyramine are the main biological amines in the late storage period of mutton.Based on the above changes in physical and chemical indicators,electromagnetic field preservation can extend the preservation period of mutton to 45 d.(2)The effects of EP and FS storage methods on the volatile flavor compounds in mutton during storage were measured using headspace solid phase microextraction gas chromatography mass spectrometry(HS-SPME-GC-MS)and headspace gas chromatography ion mobility spectroscopy(HS-GC-IMS).The results showed that the volatile flavor compounds in the two storage methods had similar trends,but there were differences in content.During storage,the types and contents of aldehydes,alcohols,esters,and alkanes all dominate.1-Octene-3-ol accounts for a large proportion during the entire storage period,and can be used as a marker flavor substance for mutton during storage.At the same time,nonanal,1-heptanol,and 2,3-butanediol,which may cause odor,were detected at the late stage of electromagnetic field storage(45 d),indicating that the flavor quality of mutton under electromagnetic field preservation began to deteriorate after 45 d of storage,which was similar to the previous physicochemical index results.(3)Based on the comprehensive physicochemical and flavor data,the differential proteomic analysis of QG mutton stored under EP and FS for 45 days was conducted using TMT-quantitative proteomics technology.Under the same storage method and different storage times,a total of 801 DEPs were selected from FS group and 818 DEPs were selected from EP group.Through biological information analysis,DEPs in both groups were mainly concentrated in single-organism metabolic process,organic acid metabolic process,purine nucleoside metabolic process,muscle system process,ATP metabolic process,etc.The main cellular components were intracellular,cytoplasmic,mitochondria,mitochondrial membranes,myofibrils,and so on.Molecular function analysis showed that binding function,oxidoreductase activity,hydrolase activity,lyase activity,and catalytic activity were dominant in the two groups.KEGG was mainly characterized by carbon metabolism,amino acid metabolism,energy metabolism,fatty acid metabolism,glutathione metabolism,and purine metabolism.A total of 292 differentially expressed proteins were screened from three comparative groups with different storage methods and the same storage time(EP-15 vs FS-15,EP-30 vs FS-30,and EP-45 vs FS-45).At the 15 d,upregulated DEPs were mainly involved in the energy metabolism process,as well as metabolic pathways,TCA cycle,β-Alanine metabolism,Apelin signaling pathway,oxidative phosphorylation,ubiquinone,and other terpene quinone biosynthesis pathways.At the 30 d,most upregulated proteins had enzymatic regulatory activity,cytoskeletal protein binding,actin binding,and protein phosphatase regulatory activity,and participate in purine metabolism,thiamine metabolism,Apelin signaling pathway,histidine metabolism,ascorbic acid,and arabinate metabolism.At the 45 d,metabolic pathways,PPAR signaling pathways,tight junctions,alanine,aspartic and glutamic acid metabolism,cysteine and methionine metabolism,cholesterol metabolism,purine metabolism,Apelin signaling pathways,ubiquinone and other terpene quinone biosynthesis were significantly enriched KEGG pathways.(4)Redundancy analysis and Spearman analysis techniques were used to analyze the correlation between physical and chemical indicators,volatile flavor substances,and differential proteins.The results showed that both storage methods showed a correlation between water holding capacity,L*,and 2-methylcyclopentanone,(E)-2-octene-1-ol,and 2-ethylethanol from 0-15 d.When stored for 30-45 d,the levels of(E)-2-nonanal,p H,phenylethylamine,and cooking loss in the frozen group were correlated,while the flavor substances such as ethyl octanoate,phenylethanol,octanoic acid,and1-heptanol in the electromagnetic field group were correlated with a* and b*;After 60 d of storage,TBARS,TVC,TVB-N,putrescine,and tyramine were associated with 1-nonyl alcohol,1-hexanal,and 1-octene-3-ol.The correlation analysis between physical and chemical indicators,volatile flavor compounds,and proteomics showed that one physical and chemical or flavor quality of mutton under two storage methods was correlated with multiple differentially expressed proteins.In FS group,differentially expressed proteins mainly affected the physical and chemical and flavor quality of mutton through regulating cell signaling pathways and muscle cytoskeleton,while in EP group,they mainly affected the quality of mutton through TCA cycle,oxidative phosphorylation,and amino acid metabolism.