Effect Of Thaw On Water-holding Capacity Of Chicken

The paper use chicken breast as raw material to study the effect of thawing methods of saturated moist air, unsaturated moist air and still water under 5℃,10℃,15℃,20℃,25℃ on the water hold capacity of chicken and take thaw loss, pressure loss, cooking loss and protein solubility(total soluble protein, sarcoplasmic protein solubility, myofibrillar protein solubility) as indicators. Combining the experiment results and the change of surface heat transfer coefficient of frozen chicken, we design a three-segment thawing process by response surface methodology to improve the thawing methods. The specific findings are as follows: 1. Effect of different kinds of thawing methods on water holding capacity of chickenWith the improvement of temperature, the thawing time was decreasing(P<0.05). Still water thawing methods spent the shortest time, unsaturated humid air thawing the longest. At 5℃, the thawing time of unsaturated humid air thawing method was close to saturated humid air thawing method. Thawing loss of still water thawing showed little change with the change of temperature and loss of unsaturated and saturated moist air thawing method was reducing with the increasing of temperature; thawing loss of still water thawing methods was lower than unsaturated and saturated humid air thawing method significantly and unsaturated humid air thawing method showed the largest thawing loss. Thawing loss of unsaturated humid air thawing method at 25℃ showed no significant variation when compared with saturated humid air thawing method at 10℃、15℃、20℃ and 25℃. All the three thawing methods showed no obvious effects on pressing and cooking loss. Total loss(pressing loss+cooking loss) and pressing loss showed an approaching changing trend. With the increasing of temperature, the total soluble protein, sarcoplasmic proteins, and myofibrillar protein solubility were decreasing when the chicken was thawed by different methods. Unsaturated humid air thawing method showed the minimum protein loss, still water thawing method the maximum protein loss. Compared with fresh, thawed chicken had low values of T21 and T22. Neither thawing methods nor temperature had significant effect on the values of P2 or T2.。indicating that the relationship between moisture migration and thawing loss need to be observed in further study.2. The optimal parameters of thawing loss and thawing time of three-segment saturated humid air thawingThe optimal parameters of thawing loss and the minimum value as flows: early stage is 21℃,metaphase is19℃,later stage is 8.2℃,the thawing loss is 7.5%.The optimal parameters of thawing time and the minimum value as flows: early stage is 24.7℃,metaphase is18.9℃,later stage is8.8℃,the thawing time is 8.95 h.