| In order to explore the effect of variety and feed on pork longissimus quality,three kinds of pork from Shanxi black pig(H),Duroc×Landrace×Yorkshire pig in Luliang Mountain pig farm(L)and other pig farms(DLY)were studied.The meat quality and transcriptome of the longissimus dorsi muscle were determined by random collected from slaughterhouse.The results indicate that:(1)The meat color and p H24 among the three kinds of pork longissimus were very significantly different(P < 0.01);The difference of cooking loss rate and dripping loss rate of three kinds of pork longissimus were significant(P < 0.05);The IMF content of H group was significantly higher than DLY group and L group(P < 0.01),and the IMF content of L group was significantly higher than DLY group(P < 0.05).(2)There was no significant difference among the three kinds of pork muscle fibers(P > 0.05).The diameter of muscle fiber of DLY was the largest and L was the smallest,the density of muscle fiber of DLY was the lowest and H was the highest.(3)There were significant differences in IMP,MUFA and Glu among the three kinds of pork longissimus.The content of IMP in H and L were significantly higher than that in DLY group(P < 0.05).The content of MUFA in DLY group was significantly lower than that in H group(P < 0.05),and C18:1content accounted for the largest proportion in MUFA.The content of PUFA in DLY group was significantly higher than that in H and L group(P < 0.05),the content of C18:2 in H group was significant lower than that in DLY and L group(P < 0.05).The content of C20:4n6 in H group was significant lower than that in DLY and L group(P < 0.01).There were significant differences in Glu and Tyr contents among different kinds of pork longissimus(P < 0.01),the content from large to small were DLY,H and L.The contents of Thr and Val from high to low were L,H and DLY(P < 0.01).The contents of Cys from high to low were H,DLY and L(P < 0.01).The contents of Ala in L was significantly higher than H and D(P <0.01).The contents of Ser and Gly in L were significantly lower than H and DLY(P < 0.05).(4)The transcriptome expression genes of the three kinds of pork longissimus were quite greatly.The result show there were 1047 differentially expressed genes in DLY group compared with H group,416 genes were up-regulated and 631 genes were down-regulated.There were 820 differentially expressed genes in L group compared with DLY group,464 of which were up-regulated and 356 down-regulated.There are 1331 differentially expressed genes in L group compared with H group,of which 757 genes are up-regulated and574 genes are down-regulated.In conclusion,IMP,MUFA(mainly C18:1)and PUFA(C18:2 and C20:4n2)may be the main flavor substance affecting the quality of pork,which is the main factor leading to the better flavor of Shanxi black pig and Lvliang Mountain pig.There were significant differences in ph24,drip loss and IMF among the three kinds of pork longissimus.The genes affecting these differences are PFKM,PGM2,ALDH2,FASN,SCD,LEP. |
