Effects of Thawing Conditions on the Physicochemical and Microbiological Quality of Thawed Beef

Abstract

This study aimed to determine the effects of thawing methods such as thawing in a refrigerator, at room temperature, in cold water, and using a microwave oven on the pH, color value, 2-thiobarbituric acid (TBA) value, water-holding capacity, thawing loss, textural attributes, microbial status, and morphology of frozen beef samples. The redness ( a* ) value of beef samples thawed in cold water for prolonged time and those thawed at room temperature for prolonged time significantly increased compared with that of samples thawed using other methods. The TBA value and thawing loss of beef samples thawed in a refrigerator were significantly lower than those of samples thawed using other methods. Regardless of the thawing method used, beef samples thawed for prolonged time showed significantly high TBA values. With regard to texture, beef samples thawed using a microwave oven showed the maximum hardness compared with those thawed using other methods. The total aerobic bacterial count in fresh beef samples was 1.98 log colony-forming unit (CFU)/g, whereas that in samples thawed at room temperature was 2.49 log CFU/g. Beef samples thawed at room temperature for prolonged time and those thawed using a microwave oven showed irregular structure. These data demonstrated that the thawing condition affects the physicochemical and microbiological qualities of beef, with thawing in a refrigerator resulting in superior beef quality than thawing at room temperature or using a microwave oven.