Effect of different cooking conditions on the quality of stewed pork with potato during storage at 12± 2℃

• Main Authors: Li-Yang Chen, 陳立揚
• Other Authors: Deng-Cheng Liou
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/37h3nh

碩士 === 國立中興大學 === 動物科學系所 === 106 === Sous vide cooking had been frequently used for meat products. Many researches demonstrated that sous vide cooking is not only efficiently to reduce microbial contamination, fat and protein denature, loss of moisture, aromatic compounds and heat sensitive nutrients of foods, also significantly to promote softness of meat, however, these products could not be kept stable for long time during storage. The objective of this study was (1) to evaluate effect of different cooking conditions: high temperature- short time (HTSt, 105℃-50, 60, 70 minutes) and low temperature-long time (sous vide) (LTLt, 75℃-16, 20, 24 hours) on sensory quality of stewed pork with potato (2) to look for an optimal shelf life for stewed pork with potato cooked by HTSt (105℃-50 minutes) and LTLt (75℃-16 hours) during storage at 12±2℃ for 8 weeks. The results of the first experiment were showed that the color, flavor and off odor in sensory for meat were not significantly different among all groups, however, the softness of vegetables and flavor of soup in the product treated with LTLt showed significantly higher score than those of HTSt, especially the most soft texture was exhibited in 75-16 group. On the other hand, a better juiciness was found in both of 75-16 and 75-24 group and 75-24 had the highest score among all groups. In overall acceptance, the product of 75-16 and 105-50 had the highest score in HTSt and LTLt groups, individually. In the second experiment, the product of HTSt group-105-50 and LTLt group-75-16 were selected for storage at 12±2℃. The results showed that in pH value: HTSt group maintained stable during storage time, but HTSt group decreased significantly with storage time and the value were lower than 6.0 at 4th week. In the fat oxidation, LTLt group showed unstable in TBA value (1.2-3.4 unit), but HTSt group kept stable change of TBA during storage (1.1-2.0). In CD value, both of HTSt and LTLt group hold stable during storage. In microbial quality, total plate count and lactic acid bacteria of HTSt group increased with storage time but did not exceed 6 log CFU/g at the end of storage. Furthermore, although the microbial quality of LTLt group was as the same as that of HTSt, the expansion pack has been occured occasionally in LTLt group after the first week during storage. In texture, both of HTSt and LTLt group showed no significant difference on shear force and chewiness at the initial of storage. However, shear force of LTLt group decreased with storage time increasing but HTSt group maintained stable during storage. In sensory analysis, since LTLt group occurred expansion pack after the first week resulted that sensory were not performed after the 2nd week during storage. The flavor of meat as well as soup, and softness of vegetables of HTSt and LTLt group showed no significant difference between treatments but color, softness and juiciness of meat in LTLt group was higher than those of HTSt group during the same storage time. In off odor, the score of LTLt group increased significantly at 1st week but that of HTSt group remained stable during 8 weeks of storage. In overall acceptance: the score of LTLt group showed no significant difference between at week 0 and 1, however, the score of HTSt group maintained higher than 4.0 during the whole storage. In conclusion, according to the results of sensory, HTSt and LTLt were suitable for preparation of stewed pork with potato. Moreover, during storage at 12± 2℃ an optimal shelf life of stewed pork with potato cooked by LTSt or HTLt was 1 week and 8 weeks, separately. Therefore, stewed pork with potato cooked by HTLt could be potential as softened food for elder people in the future.