[目的]揭示猪宰后肌肉的非乳酸(CP+ADP→Cr+ATP,ATP-CP)供能特点及其与肉质性状的关系,为猪肉品质调控与形成机制的研究提供参考.[方法]选取上市体重金华猪、浙江中白猪、杜浙猪(杜洛克×浙江中白猪)和杜大长猪(杜洛克×(大约克×长白猪))阉公猪各8头,屠宰后测定背最长肌和腰大肌的肉质性状(pH45min、pH24h,剪切力(SF)、系水力(WHC),宰后24 h蛋白质溶解度)、肌酸激酶(creatine kinase,CK)与三磷酸腺苷酶(adenosine triphosphatase,ATPase)活性、高能磷酸化合物(adenosine diphosphate,ADP; adenosinetriphosphate,ATP; creatine,or; creatine phosphate,CP)含量,并用M=([ATP]+[Cr])/([ADP]+[CP])表示宰后45 min的ATP-CP反应进程,用N=(CK+ATPase)×M表示ATP-CP供能潜力,比较各指标的品种或部位间差异,分析ATP-CP状态与肉质性状的关系.[结果]与背最长肌相比,腰大肌表现较高的ck活性、pH24h、肌肉总蛋白溶解度(杜浙猪除外),肌纤维蛋白溶解度.M值和N值(金华猪除外)(P和△pH均按此顺序表现升高趋势;背最长肌的M值与pH、△pH呈负相关(r=-0.811,r=0.908,P呈正相关(产r=0.876,P<0.01),与△pH、pH45min呈负相关(r=-0.711,P<0.01;r=-0.385,P<0.05),与其它肉质性状的相关性表现复杂.[结论]宰后肌肉ATP-CP反应进程(M)和反应潜力(N)在背最长肌随本地猪血统比例增加而增大,在腰大肌随本地猪血统比例增加而降低,在金华猪腰大肌低于背最长肌,在其它品种腰大肌高于背最长肌,并与宰后肌肉pH密切相关,可以减缓宰后24h内pH下降程度,但与其它肉质性状的关系需要进一步研究证实.%[Objective]To study the role of ATP-CP system in postmortem muscle on the formation of pork quality, this research investigated the effects of pig breeds and muscle types on ATP-CP status and their possible associations with pork quality traits.[Method]Longissimus dorsi (L.D.) and psoas major (P.M.) of Jinhua pure breed (JH), Zhongbai pure breed (ZB), Duroc ×Zhongbai (DZ) cross and Duroc × (Yorkshire×Landrace) (DYL) cross were sampled, and ATP-CP status (including the concentration of ADP, ATP, creatine and creatine phosphate and creatine kinase, ATPase activities) and mcat quality traits (including pH45min, PH24h, shear force (SF), water-holding capacity (WHC), total protein solubility (TPS), sarcoplasmic protein solubility (SPS)and myofibril protein solubility (MPS)) were measured.The reaction process and the potentiality of ATP-CP pathway were described as M=([ATP]+[Cr])/([ADP]+[CP]) and N=(CK+ATPase)× M, respectively.One-way ANOVA and Duncan's test were employed to analyze the difference among different pig breeds.Independent T- test was used to analyze the difference between L.D.and P.M.[Result]P.M.exhibited a higher CK activity, pH24h, TPS, MPS, M-value, N-value (P＜0.05) and a lower pH45min, ΔpH, SF, WHC,SPS than L.D.(P＜0.05), the activities of CK and ATPase activities in both L.D.and P.M.muscles, M-value and N-value in L.D.muscle but not P.M.muscle declined according to the order of JH→ZB→DZ→DYL, pH4smin and Δ pH in both muscles increased according to the above order.A negative correlation between M-value and pH45min (r=0.811, P＜0.01) or Δ pH (r=0.908, P＜0.01)or between N-value andΔ pH (r=0.711, P＜0.01) or pH45min (r=0.385, P＜0.05), a positive correlation between N-value and pH24h (r =0.876, P＜0.01) were found in L.D.muscle.[Conclusion]The results indicated that ATP-CP reaction process (M) and potentiality (N) were both increased in the order of DYL→DZ→ZB→JH in L.D.muscle, reversely in P.M.muscle.In JH pigs,ATP-CP reaction process (M) and potentiality (N) of P.M.muscle are both lower than the ones of L.D.muscle, which is reverse in other pigs.And ATP-CP pathway is associated with the postmortem pH, and can alleviate the decline of pH in 24 hatter slaughtering and its relationships to other meat quality traits were also found and need further to be studied.
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