Effect Of Postmortem Ageing On The Formation Of Characteristic Quality Of Braised Chicken

Dezhou braised chickent is loved by consumers for its tender meat,ripe rotten and boneless,and delicious taste.Compared with the traditional roast chicken,the meat quality of the braised chicken is more delicate due to the special technology of“pa”,especially the chicken breast.When the chicken is torn open by hand,it can be seen that the chicken fibers are like silver silk.,because the carcass is not postmortem ageing,the muscle fibers have hardly degraded and the structure has not been destroyed.In factory,the chicken carcass is processed immediately after slaughter,but a large number of studies have shown that the meat texture and taste after ageing are better,but for the processed braised chicken,further research is needed.In this study,the North China Chai Chicken,a raw chicken breed of Dezhou braised chicken,was investigated.The North China Chai Chicken(male,70-day-old age,carcass weight800-1000 g)with the same nutrient level were randomly selected and divided into two groups,and which all were placed at 4℃for ageing.A group of chicken carcasses were taken to determine the pH value,color(L~*,a~*,b~*value),the cooking loss rate,pressing loss water,the shear force value,myofibril fragmentation index,microstructure,and muscle fiber diameter of the chicken breast.The other samples were processed to braised chicken at the same time point.After cooling,the yield,pH value,color,pressing loss water,shear force value,moisture content and crude fat content texture characteristics and sensory score of the braised chicken were determined.At the same time,the effects of pre-cooling tank on braised chicken in different production processes in different production processes were determined.The main research contents and results were listed as follows:(1)The variation regularity of various indexes of chicken carcassWith post-mortem ageing,the chicken carcass experienced a process from stiffness to maturation.During the conversion of muscle to meat,the pH value of the chicken carcass decreased first and then increased,reaching the ultimate pH value at 4 h after slaughter.The L~*value increased first then decreased and then increased.The a~*value increased first and then decreased,and the b~*value increased first,then decreased and finally rose.The shear force value first increased and then decreased.The cooking loss rate and the pressing loss rate were both increased first and then decreased,indicating that the water-holding capacity first decreased and then increased.The MFI value of chicken was gradually increasing.As the ageing time prolongs,the muscle fibers become looser from the arrangement orderly dense,and there was a gap between the muscle fibers,and the diameter of the muscle fibers was continuously reduced.There was a negative correlation between pH value and pressing loss water and cooking loss.The shear force value had a high negative correlation with MFI(P<0.01)and a significant positive correlation with muscle fiber diameter(P<0.05).The meat quality of chicken carcasses of before maximum rigidity and after proper ageing is different,and further research on the processed braised chicken was needed.(2)Effect of postmortem ageing on the quality of braised chickenThe results showed that the yield of braised chicken was significantly improved(P<0.05)after appropriate ageing,and finally stabilized.The pH value of the braised chicken first decreased and then stabilized,but the overall value range was small.Both the shear force and the pressing loss rate of the braised chicken increased first and then decreased.The L~*value and the b~*value gradually increased,and the a~*value first decreased and then rose.The moisture content was relatively larger at 2-6 h of ageing and decreased after 6 h.The crude fat content first increased,then decreased and rose later,reached a maximum at 4h.The hardness,cohesiveness and chewing of chicken breast decreased first,increased and then decreased,and increased at 24h.The texture indexes such as hardness and elasticity of chicken breast were significantly higher than those of chicken leg.There is a general correlation between the ageing time of braised chicken and most indicators of food quality.The pH value and shear force value of chicken breast were significantly positively correlated(P<0.01),and positively correlated with the pressing loss rate(P<0.05).The shear force value of the braised chicken and the pressing loss rate were significantly positive(P<0.01).On this basis,the influence of the existing pre-cooling process on the quality of the braised chicken was further measured and the effects of the pre-cooling tank of the chicken carcass at different times on the finished pheasant were measured.According to the results of various indicators,it can be seen that the results of the braised chicken processed by a pre-cooling tank and the braised chicken processed by two pre-cooling tanks are not much different.Considering the production time and production cost of the workshop,the chicken carcass is slaughtered.After completion,a pre-cooling tank is preferred.Considering the comprehensive indicators of braised chicken,ageing time and economic benefits of the plant,it is recommended that the optimum ageing of chicken carcass is 2 h at 4°C which was suitable for braised chicken technology.Equivalent to the effect of passing a pre-cooling tank.This paper revealed the quality changes after ageing of raw chicken and explored the effect of different postmortem ageing levels on the formation of characteristic quality of braised chicken.In the actual production of the factory,the processing enterprise can reasonably adjust the way and time of postmortem ageing of the chicken carcass according the specific production situation of the workshop,so as to save the cost of ageing,reduce the production cost,and provide a theoretical reference for the standardized production of the enterprise.