Effects of Different Thawing Methods on Pork Physicochemical Properties and Microbial Counts
ZHENG Xu1, ZENG Lu1, BAI Xianze1, WANG Chuanhua1, HOU Aixiang1,2,*
1.College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China; 2.Hunan Provincial Engineering and Technology Research Center for Fermented Food, Changsha 410128, China
Abstract：The aim of this study was to investigate the effects of thawing methods on pork quality. Thawing loss, cooking loss, shear force, color, pH value, total volatile basic nitrogen (TVB-N) content, thiobarbituric acid reactive substance (TBARs) value, aerobic bacterial count and Lactobacillus count were measured after thawing by four different methods, i.e. natural air thawing, thawing at 4 ℃ in a refrigerator, still water thawing and microwave thawing. The results showed that the thawing loss, cooking loss, brightness value, redness value, TVB-N content and TBARs value of frozen pork thawed in still water were 2.74%, 16.60%, 57.12, 13.94, 12.95 mg/100 g and 0.10 mg/100 g, respectively, which were lower than those observed using other thawing methods, the pH value was close to that of fresh pork, and the aerobic bacterial count and Lactobacillus count were lower. Accordingly, the thawed pork maintained good physicochemical properties. The frozen pork thawed at 4 ℃ showed the lowest shear force (25.41 N) and maintained good tenderness. The microwave-thawed sample had the lowest yellowness value (11.06). The aerobic bacterial count and Lactobacillus count in thawed pork samples showed a fluctuating trend with freezing time. The physicochemical properties of thawed pork were significantly or highly significantly affected by microbial counts. Among the four thawing methods, still water thawing provided better maintenance of pork quality.
2018, Vol. 32 
