Changes in Eating Quality of Lamb during Postmortem Storage
XIAO Xiong, HOU Chengli, LI Xin, ZHENG Xiaochun, ZHANG Dequan, REN Chi, BAI Yuqiang, YAN Tongjing, LIU Dengyong
1.Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; 2.Food Safety Key Laboratory of Liaoning Province, College of Food Science and Engineering, Bohai University, Jinzhou 121013, China
Abstract：This investigation aimed to study the difference in the eating quality of lamb meat at different postmortem times. The Longissimus dorsi muscle was sampled and measured for central temperature, total colony number, pH value, sarcomere length, shear force, meat color, myoglobin content and cooking loss at different postmortem times (1, 6, 12, 24, 72, 120 and 168 h), and the internal temperature and total viable count were also monitored during postmortem aging. The results showed that the pH value of lamb decreased from 6.45 at 1 h to 5.40 at 120 h after slaughter. The sarcomere length did not significantly differ between at 1 and 6 h (P > 0.05), reaching the lowest at 12 h, and then beginning to increase at 24 h, while no significant difference was observed between at 120 and 168 h (P > 0.05). The brightness value (L*) increased with the prolongation of postmortem time, while the redness value (a*) and yellowness value (b*) increased first and then decreased, and the content of oxymyoglobin was consistent with the change in a*. The shear force increased first then decreased, reaching its maximum at 12 h; the cooking loss at 1 h postmortem was the lowest, and then increased, reaching a maximum at 168 h. Therefore, lamb before 6 h postmortem was in the stage of pre-rigor, at 6–24 h in the stage of rigor, at 24–120 h in the stage of post-rigor, and the stiffness process was completed at 120 h. The eating quality of pre and post-rigor lamb meat was different. Pre-rigor lamb muscle had higher water holding capacity, while post-rigor lamb had higher tenderness, lightness and redness.
2019, Vol. 33 
