Studies On The Color Stability Of Ready-to-eat Chicken Breast Prepared With Capsanthin

Ready-to-eat chicken breast is a type of emerging ready-prepared food that is mainly composed of chicken breast,spices,colorant additives and cornstarch.Ready-to-eat chicken breast is well-received and loved by consumers for its delicious taste,bound of nutrition and convenient to eat.Capsanthin,is an essential component to ready-to-eat chicken breast due to the ability to confer the products with attractive color.However,capsanthin belongs to the carotenoid pigments,having a highly conjugated double bonds system that is prone to fade during the storage.It is reported that ready-to-eat chicken breast prepared with capsanthin is vulnerable to discolorate which is responsible for decreasing of sensory quality and commercial value of the products.Otherwise,a lot of researches have been reported regarding the stability of capsanthin,but the findings about the color stability applied to the prepared chicken breast has not been reported.The objective of the thesis was to investigate the effect of storage temperatures and natural antioxidants on discoloration of chicken breast prepared with capsanthin.The ready-to-eat chicken breast was prepared according to the method from industrial production.Capsanthin is the main coloring matter of ready-to-eat chicken breast and becomes a key factor on discoloration of the products due to the oxidative degradation during storage.The most correlated indexes were chosen to evaluate the effect of different temperatures on discoloration of prepared chicken breast during the storage and find out whether there exists some correlation between discoloration and oxidation of the products.The next step was to find out the influence of antioxidations on the stability of color and lipid oxidation of prepared chicken breast.Optimization was carried out using two factors including rosemary extract and ascorbic acid,and the two responses studied were a*values and thiobarbituric acid-reactive substance(TBARS)to obtain a higher redness and lower TBARS values of prepared chicken breast.A verification experiment should be designed to convince the accuracy of the verdict.The results will provide a theoretical basis for industrial production of prepared chicken breast.1.Effect of storage temperatures on color stability of ready-to eat chicken breast prepared with capsanthinThe purpose of this study was to investigate the effect of storage temperatures on color stability of prepared chicken breast with capsanthin.Freshly prepared chicken breast containing capsanthin was frozen at-20? for 24 hours,then stored without light at-2?,-10?,-18?,and an oscillating temperature between-10? and-18?(the storage temperature altered every 12 h).The indexes including moisture content,color parameters,the color unites of capsanthin,TBARS values,carbonyl contents and sulfhydryl contents were determined per week.It showed that the storage temperature has a significant influence on the loss of redness.5 weeks later,redness of prepared chicken breast decreased 15.57%,11.95%,10.89%,5.31%at-2 0C,-10?,-10?/-18? respectively,while samples stored at-18? decreased 5.31%.Similarly,lower contents of capsanthin was tested in the groups which have a great loss in redness.The highest TBARS values and carbonyl contents,lowest sulfhydryl groups were observed in samples stored at-2? for 5 weeks.Also,the results suggest a significant correlation between redness and Chroma,hue,the color unite of capsanthin,TBARS values and active sulfhydryl contents by the correlation analysis.No striking correlation was observed between redness and lightness,yellowness,total sulfhydryl groups and moisture contents.The findings indicated that color stability of prepared chicken breast was successfully enhanced when stored at a lower and more stable temperature.2.Optimization of process of inhibiting discoloration and lipid oxidation in prepared chicken breast using natural antioxidant by response surface methodologyThe aims of this study were to optimize the concentration of natural antioxidants for the preparation of chicken breast using central composite design.To obtain a higher redness and lower TBARS values of prepared chicken breast,the single-factor experiment was carried out to optimize two factors such as rosemary extract and ascorbic acid and the two responses studied were a*values and thiobarbituric acid-reactive substance(TBARS).A verification experiment should be designed to convince the accuracy of the verdict.It was observed that the addition of rosemary extract and ascorbic acid have significant influence on a*and TBARS values.The R2 of two models were found to be 0.9320 and 0.8863,respectively,the lack of fit was considered to be marginally non-significant(P>0.05),indicating that the models appropriately explain the variability of the observed responses.The optimum concentrations were demonstrated as follows:rosemary extract:0.198 g/kg;ascorbic acid:0.255 g/kg.The redness values reached 21.88 and the TBARS values were 0.59 mg MDA/kg meat of prepared chicken breasts under the optimum conditions.