Abstract:

In order to investigate the characteristics of Wenshi chicken during freezing process, four freezing rates such as ultrarapid freezing at 11.46 cm/h, rapid freezing at 4.21 or 2.07 cm/h and slow freezing at 0.25 cm/h were studied to examine the effect on characteristics of chicken through evaluating its drip loss rate, protein denaturation and texture. Results indicated that the reduction rate of salt-soluble protein content and Ca2+-ATPase activity and drop loss rate in Wenshi chicken displayed a change trend to first drop and then rise as freezing rate rose. However, No obvious change in the activity of other ATPase enzymes was observed at different freezing rate conditions. Differential scanning calorimetric (DSC) analysis exhibited that protein denaturation after being frozen had a good correlation with traditional methods (R2 = 0.8367). Denaturation degree of myosin heads was larger than sarcoplasmic protein and myosin tails throughout freezing process. With increasing freezing rate, the hardness and chewiness of Wenshi chicken exhibited an increase, while the elasticity and resilience exhibited a decrease. According to comprehensive evaluation and texture analysis, increasing freezing rate will be helpful to maintain original quality of Wenshi chicken, but ultra rapid freezing rate can result in the damage of its original quality.

Key words: Wenshi chicken, freezing rate, protein denaturation, texture, DSC