To clarify the relationship between the fiber type composition and meat quality, we performed metabolomic analysis using porcine longissimus dorsi (LD) muscles. In the LD of pigs raised outdoors, the expression of myosin heavy chain (MyHC)1 (slow-twitch fiber marker protein) was significantly increased compared with that of MyHC1 in pigs raised in an indoor pen, suggesting that rearing outdoors could be considered as an exercise treatment. These LD samples were subjected to metabolomic analysis for examining the profile of most primary and secondary metabolites. We found that the sex of the animal and exercise stimulation had a strong influence on the metabolomic profile in the porcine skeletal muscles, and this difference in the metabolomic profile is likely in part due to the changes in the muscle fiber type. We also examined the effects of cooking (70 °C for 1 h). The effect of exercise on the metabolomic profile was also maintained in the cooked muscle tissues. Cooking treatment resulted in an increase in some of the metabolite levels while decreasing in some other metabolite levels. Thus, our study could indicate the effect of the sex of the animal, exercise stimulus, and cooking on the metabolomic profile of pork meat.

中文翻译：

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性别，饲养和烹饪对猪肌肉代谢组学谱的影响。

为了阐明纤维类型组成与肉质之间的关系，我们使用猪背最长肌（LD）肌肉进行了代谢组学分析。在室外饲养的猪的LD中，与在室内围栏饲养的猪的MyHC1相比，肌球蛋白重链（MyHC）1（慢肌纤维标记蛋白）的表达显着增加，这表明可以考虑在室外饲养运动疗法。对这些LD样品进行了代谢组学分析，以检查大多数主要和次要代谢物的概况。我们发现动物的性别和运动刺激对猪骨骼肌的代谢组学特征有很大的影响，这种代谢组学特征的差异可能部分归因于肌肉纤维类型的变化。我们还检查了烹饪的效果（70°C持续1 h）。运动对代谢组学的影响在煮熟的肌肉组织中也得以保持。烹饪处理导致某些代谢物水平升高，而其他某些代谢物水平降低。因此，我们的研究可以表明动物性别，运动刺激和烹饪对猪肉代谢组学特性的影响。