A Comparative Study On The Chilled Chicken Meat Quality Of Different Varieties And Under Different Storage Conditions

Poultry meat has become the world's largest source of animal protein,and the safety of poultry products has also received extensive attention.Facing various safety risks brought by the live poultry trade,the safer and more convenient consumption of chilled chicken has become the general trend.For chilled chicken,the meat quality is the ultimate criterion of evaluating poultry products.Therefore,it will provide a theoretical basis for the evaluation of high-quality chicken,ensuring the shelf life of chilled chicken and the smooth promotion of the chilled chicken market that studying on the quality of different varieties chicken and meat quality change rules of chilled chicken under different storage conditions.In this study,broilers with different speed of growth(817 hybrid broiler?Xinguang partridge shank chicken?Xinxing dwarf yellow chicken and Yao chickensynthetic line)were selected to study its meat quality characteristics through a comparative analysis of slaughter performance and meat quality at their respectivemarketing age.And Suqin yellow chicken were selected to study the meat quality change rules under different storage methods(refrigerate at 4? and repeated frozen-thawed)andtime(storage at 4? for 1?7 d,repeated freezing and thawing for 1-7 times).The results were as following:1.The quality of broilersvarieties(lines)of different growth ratesshowed their own characteristics.817 hybrid broilers had thecharacteristics of highest carcass rate,lower shear force,higher protein content,lowerIMP and lower drip loss.Compared with 817 hybrid broilers,the common characteristics of the three yellow-feather broilers were the brighter color of the meat,the relatively higher contents of intramuscular fat and IMP,and better abdominal fat rate.Among them,the crude protein content of the Xinguang partridge shank chicken wasthe highest.While the IMP content of the Xinxing dwarf yellow chicken was the highest,and its dripping loss was also higher than other varieties.The Yao chickensynthetic line was with the obvious features of the color of the muscle,IMP content and intramuscular fat content.2.It was found that the color of broilers skin surfacerefrigeratedat 4? would turn yellow and light with the prolongation of storage time,while the color of broilers skin in the repeated frozen-thawed group would turn dull-red and then turn light.The brightness of skin in the repeated frozen-thawed group decreased faster than that in the refrigerated group,and the shear force value changed greater.3.The level of meat umami substances contents stored for once in the repeated frozen-thawed group was lower than that stored for 7 days in refrigerated group.The total free amino acid content,taste amino acid content,essential amino acid content and lysine content of the two groups bothfirstly increased significantly and then decreased.And the content of aspartic acid and glutamic acid that are the mian substances of fresh flavor showed significant increase.While the percentage of essential amino acids and lysine decreased significantly in both groups.Compared with the refrigerated group,the frozen-thawed group had a larger variation range.When refrigerated at 4? the TVB-N value crossed the first-grade freshness limit at 5d and reached the limit of spoiled meat at 7d;the repeated frozen-thawed group exceeded the first-grade freshness limit at 4 frozen-thawed cycles,and reached the limit of spoiled meat at 6 cycles.Thelevel of aerobic bacterial count in the refrigerated group was in the fresh meat range at 1 to 3 days,in the sub-fresh meat range at 4 to 5 days,and was close to spoiled meat at 6 to 7 days while thelevel of aerobic bacterial countin the freeze-thaw group was still in the fresh meat rangeafter 7 frozen-thawed cycles.It revealed that lower temperature storage can inhibitthe reproduction of bacterias.In all,different growth rate types of broiler varieties(lines)showed their own quality characteristics,which provided reference for processing and consumption of different varieties broilers and accumulated basic data for meat quality identification of chilled chicken.Under refrigerated storage,the chicken meat quality at 1?3 d was the bestand the shelf life should not exceed 5d.And under repeated frozen-thawed storage,that occurs more frequently as unconventional storage,the chicken meat had no significant effect when frozen-thawed once comparing with fresh meat,and can be eaten after repeating frozen-thawed 2?3 cycle,but was not recommended after more than 4 cycles.