Effects Of Different Thawing Methods On The Quality Of Chicken Breast

Thawing method is closely related to the quality of frozen meat.It is confirmed that appropriate thawing method could reduce the degrees of lipid and protein oxidations and protein denaturation,decrease the loss of thawing loss,improve the color,which further influence meat quality.The aim of this study was to evaluate the effects of ultrasonic thawing methods under different power levels and low temperature thawing methods under different humidity conditions on meat quality of chicken breast.The differences in water holding capacity(WHC),color,tenderness,the degrees of lipid and protein oxidations and protein denaturation,freshness and water distribution were analyzed.In addition,the research was designed to study the effect of different thawing methods on eating quality,the degrees of lipid and protein oxidations and protein denaturation,microstruture and myofibril protein degradation of chicken breast.Special attention was paid to the differences between single thawing methods and combined thawing methods.These results can be taken into consideration to develop strategies in order to improve the quality of chicken breast during freezing and thawing process.The purpose of this study was to improve the meat quality of thawed chicken breast,thus providing theoretical reference and technical support for choose the suitable thawing method in actual production.This study consists of three parts,the main studying contents and the test results were as follows:1.Effects of ultrasonic thawing methods under different power levels on the quality of chicken breastThe effect of ultrasonic thawing method on the quality characteristics of chicken breast was investigated.Taking the method of water thawing(15?)as control group while the method of thawing under four different ultrasonic powers as experimental groups(15?;120,180,240,300w),the differences in quality characteristics parameters of chicken breast were analyzed among five thawing samples.The results showed that significant differences existed on quality changes of chicken breast with the increase of ultrasonic power.Compared with control group,the thawing time,total sulfhydryl content,total volatile basic nitrogen and the total bacterial count of thawed chicken breast in the experimental groups decreased significantly(P<0.05).However,The thawing loss,a*value,T23 peak area ratio of all ultrasonic thawing treatments were increased significantly(P<0.05),and the pH value,L*value,the total protein solubility,myofibril protein solubility were significantly lower than control group(P<0.05).The shear force,total protein solubility and myofibril protein solubility in 120 W and 180 W of ultrasonic power thawing methods were significantly higher than the groups of 240 W and 300 W(P<0.05),and thawing time,malondialdehyde content,T23 peak area ratio was significantly lower(P<0.05).But the lower thawing time and total bacterial count were resulted from the power of 180 W ultrasonic thawing method(P<0.05).Comprehensive analysis,the ultrasonic power thawing treatment could effectively shorten thawing time and improve the freshness of chicken breast.However,it had a detrimental effect on water-holding capacity and color.Moreover,it also could exacerbate the degree of protein oxidation and protein denaturation.And when the ultrasonic power of thawing was under 180 W,the negative effect on chicken breast was minimal.2.Effects of different humidity thawing methods at low temperature on the quality of chicken breastThe effects of low temperature thawing under different humidity(4?)on the quality characteristics of chicken breast were investigated.Low temperature refrigerator thawing(4?;Relative humidity,RH 65%?RH 81%)as control group meanwhile four different humidity(4?;RH 80%,RH 85%,RH 90%,RH 95%)thawing methods as experimental groups,the differences in thawing time,drip loss,pH,shear force,texture,color,protein solubility,malondialdehyde content,total sulfhydryl content,total bacterial count,total volatile basic nitrogen(TVB-N)and water distribution influences were analyzed among five thawing samples.The results showed that significant impacts existed on quality changes of chicken breast with increasing relative humidity,meanwhile,thawing time increasing.RH 90%and RH 95%low temperature thawing methods in thawing drip loss,T23 peak area ratio were significantly lower than the control group(P<0.05),but hardness,chewiness,L*value,a*value,total protein solubility,sarcoplasmic protein solubility,total sulfhydryl content,T22 peak area ratio were significantly higher(P<0.05).However,significantly higher malondialdehyde content,total bacterial count and TVB-N content were resulted from RH 95%low temperature thawing method(P<0.05).In conclusion,the chicken breast obtained best quality through RH 90%low temperature thawing method which could effectively decrease muscle protein oxidation and protein denaturation,reduce thawing drip loss and improve the color in thawing process.3.Effects of different thawing methods on quality of chicken breastThis study aimed to investigate the effects of freezing and different thawing methods(Control group,CG;water immersing thawing,WT;low temperature combined with high-humidity thawing,LT;combined thawing 1(WT 15min,then LT),CT1;combined thawing 2(LT 2h,then WT),CT2)on quality of chicken breast.The results showed that all thawing methods significantly increased shear force value,the gap between muscle fibers,the contents of malondialdehyde(MDA)and carbonyl compounds,meanwhile,decreased the pH,a*value,total protein solubility and sarcoplasmic protein solubility,compared with CG(P<0.05).Among different thawing methods,LT was most effective in decreasing thawing loss but it had the highest contents of MDA and carbonyl compounds(P<0.05).CT1 significantly decreased shear force value,hardness and MDA content(P<0.05).Overall,freezing and thawing process had a detrimental effect on quality of chicken breast and the extent was pronounced with different thawing methods.On the basis of shortening thawing time and keeping meat quality,the results of this study suggested that CT1 could be chosen as a better thawing method.