Effect Of Freezing And Frozen Storage On The Eating Quality Of Chicken Breast Meat

Frozen storage is a primary method for meat preservation. There are a series of physical and chemical reactions during freezing and frozen storage, which has significant effect on the eating quality of meat. As a source of high quality protein, chicken meat has low content of fat and cholesterol, high content of unsaturated fatty acids, essential vitamin and mineral, which attracts more and more consumers. Therefore, the present study is designed to investigate the changes of water holding capacity, color, proteins, fatty acids in chicken breast meat during freezing and frozen storage. The purpose of this research is to elucidate the variation of the eating quality of breast meat and provide a theory basis and technique for the assurance of the eating quality of frozen chicken meat.1. Effect of different freezing rate on the eating quality of chicken breast meatTo investigate the effect of different freezing rate on the eating quality of chicken breast meat, breast meat samples from24chickens which were slaughtered and chilled for8hours were divided into three groups, one frozen at—15℃, one at—25℃and one at—35℃. Freezing rate, thawing loss rate, pressure loss rate, cooking loss rate, color, protein solubility, TBARS value and Ca2+-ATPase activity were detected. The effect of different freezing rate on the T2relaxometry of water in chicken breast meat was also explored using low-field NMR. The results showed when the freezing rate increased, thawing loss rate, pressure loss rate, cooking loss rate, b*and TBARS value decreased, while L*, a*, Ca2+-ATPase activity and NMR T22area percentage increased significantly (p<0.05). Freezing rate had no significant effect on protein solubility (p>0.05). All these results indicated that quicker freezing rate result in better eating quality of chicken breast meat.2. Effect of different frozen storage temperature and period on the eating quality of chicken breast meatThe effect of frozen storage temperature (—35℃,—25℃,—15℃) and period (0d,30d,60d,90d,120d,150d,180d) on the eating quality of chicken breast meat was investigated by measuring the changes of thawing loss rate, NMR T22area percentage, color, protein solubility, Ca2+-ATPase activity, TBARS value and TVB-N content. As frozen storage temperature and period increased, thawing loss rate, b*value, TBARS value, TVB-N content of chicken breast meat increased, but T22area percentage, L*value, total and myofibrillar protein solubilities, Ca2+-ATPase activity decreased (p<0.05). A marked increase in a*value was observed up to30days, followed by continuous decrease up to180days of storage (p<0.05). The a*value decreased with increasing frozen storage temperature as well (p<0.05). Frozen storage temperature had no significant effect on the solubility of sarcoplasmic proteins, but the sarcoplasmic protein solubility decreased as frozen storage period increased (p<0.05). This confirmed that the eating quality of chicken breast meat deteriorated gradually during frozen storage and that higher temperature resulted in lower eating quality.