Sasaki Keisuke, Motoyama Michiyo, Mitsumoto Mitsuru
National Institute of Livestock and Grassland Science, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, Japan.
Meat Sci. 2007 Oct;77(2):167-72. doi: 10.1016/j.meatsci.2007.02.025. Epub 2007 Mar 12.
Time course changes in amounts of glutamic acid, total free amino acid, inosine monophosphate (IMP), and 2%-trichloroacetic acid-soluble oligopeptides in whole, muscle only, and cooking juice during wet-heat cooking in pork longissimus and biceps femoris muscles were investigated because the movements of umami-relevant substances during cooking treatment had not previously been clarified in detail. The amounts of glutamic acid, total free amino acid, and IMP significantly (P<.05) decreased and increased in muscle and cooking juice during 180min of cooking, respectively. The whole amounts of glutamic acid and total free amino acid remained unchanged during cooking treatment. The whole amount of IMP, however, increased significantly at 10min of cooking (P<.05) and was maintained after the 10-min period. The extramuscular oligopeptides amount increased significantly in response to the cooking treatment (P<.05). The intramuscular amount of oligopeptides decreased at 30min of cooking but increased significantly (P<.05) after 60min. The whole meat oligopeptides amount increased significantly during a 180-min cooking treatment (P<.05). These results indicate that glutamate, total free amino acid, and IMP were released from the muscle during cooking, and that IMP levels increased in the initial phase of cooking. In addition, oligopeptides increased during wet-heat cooking of pork muscles.
由于此前尚未详细阐明烹饪处理过程中鲜味相关物质的变化情况，因此研究了猪背最长肌和股二头肌在湿热烹饪过程中，全肉、仅肌肉部分以及烹饪汁液中谷氨酸、总游离氨基酸、肌苷一磷酸（IMP）和2%-三氯乙酸可溶性寡肽含量随时间的变化。在180分钟的烹饪过程中，肌肉中的谷氨酸、总游离氨基酸和IMP含量显著（P<0.05）下降，而烹饪汁液中的这些物质含量则显著增加。在烹饪处理过程中，全肉中的谷氨酸和总游离氨基酸总量保持不变。然而，IMP的总量在烹饪10分钟时显著增加（P<0.05），并在10分钟后保持这一水平。肌肉外的寡肽含量因烹饪处理而显著增加（P<0.05）。肌肉内的寡肽含量在烹饪30分钟时下降，但在60分钟后显著增加（P<0.05）。在180分钟的烹饪处理过程中，全肉中的寡肽含量显著增加（P<0.05）。这些结果表明，烹饪过程中谷氨酸、总游离氨基酸和IMP从肌肉中释放出来，并且IMP水平在烹饪初期有所增加。此外，猪肉肌肉在湿热烹饪过程中寡肽含量增加。
