Study On Processing Quality And Suitability Of Driedchicken Slice And Floss Of Spent Laying Hens

In recent years,the layer breeding industry has been developing rapidly.The spent laying hens have high protein content,low fat content and low cholesterol content,unique flavor and rich nutritional value characteristics that broilers cannot compare with.It has certain advantages and value to produce chicken products with the spent laying hens as raw materials.Meat floss and meat slice are Chinese traditional dried meat products,which are deeply welcomed by consumers.They are characterized by high nutritional value,rich flavor and easy digestion and absorption.However,the muscle fiber layers of spent laying hens are thin,and short,the decrease of collagen solubility and the increase of connective tissue cross-linking during the hens'growth lead to its poor meat quality.In addition,its processing and utilization degree is low.Therefore,many enterprises are reluctant to choose it as raw materials for further production and processing,which caused the waste of chicken resources.Therefore,in this study,the edible quality,nutritional quality physical and chemical properties of spent laying hens before processing were analyzed by comparing with conventional broilers.The color(L~*,a~*,b~*values),pH,shear force,texture characteristics,cooking loss,intramuscular fat content and collagen content of breast and thigh muscle were investigated.The odor and taste of breast muscle and thigh muscle was measured and compared by using electronic tongue,electronic nose,gas chromatography and mass spectrometry.The water activity,physical property index,forming quality and flavor of processed meat floss were measured.The shearing force,color,texture characteristics and flavor of processed meat preserves were measured.The sensory evaluation of meat floss and meat slice was also carried out.The correlation analysis was used to establish the relationship between the quality of raw meat and processed meat floss and meat slice,and the suitability of processing meat floss and meat slice was comprehensively evaluated,which can provide theoretical reference for optimizing of spent laying hens to suit the current market and promote the development of China's layer breeding industry.The results are as follows:(1)The color,pH,shear force,texture characteristics,cooking loss,intramuscular fat and collagen content of breast muscle and thigh muscle were different between the two chicken raw materials.Among them,the broiler breast meat has higher L~*and b~*values,the pH value of the spent layer breast is the lowest,and the shear force of the spent layer leg is the largest.The hardness of the spent layer breast and thigh meat is greater than that of the broiler.The content of hydroxyproline in layer chicken breast is also higher,while the fat content of the spent layer is lower,and the cooking loss is the smallest,indicating that the meat of the spent layer is less tender,harder,but has better water retention.Correlation analysis showed that there was a certain correlation between each index of chicken breast and chicken thigh,and the shear force value was significantly correlated with cooking loss,with a correlation coefficient of 0.898.In the production and processing process,the nature of raw chicken will also determine the quality of processed meat products.(2)The shearing force value of laying hens meat slice without ingredients was 2.3,which was significantly higher than that of the other three kinds meat slice(P<0.05).The breast L~*and b~*values of layers with ingredients were significantly higher than those of common broilers(P<0.05).The hardness,chewability and adhesion of laying hens meat slice with ingredients were significantly higher than those of common broilers,but the elasticity and cohesion were not significant.A total of 56 volatile compounds were identified in laying hens meat slice including 33 hydrocarbons,11 alcohols,5 aldehydes,4ketones,1 furan and 2 ethers.The identified volatile compounds in spent laying hens meat slice is higher than ordinary chicken,among which,hexanal accounted for the highest relative content.Alkanes and aldehydes are the most abundant volatile substances,and there is little difference in taste between the two kinds of meat slice with and without ingredients.(3)The water activity value of meat floss processed by laying hens was between 0.65and 0.74.There was no significant difference in the hardness between the meat floss of laying hens and other kinds of meat floss on the market.The chewability and adhesion of meat floss with adding ingredients were greater than those without ingredients.The floss content of common broilers without ingredients was lower,but the floss content of broilers with ingredients was significantly different(P<0.05).The fluffiness degree of the layers hens and the common broilers was lower and different,but the fluffiness degree of the supplemented layers was not significantly different(P<0.05),the net fluidity of layers hens and common broilers was lower,and the fluidity of common broilers was the lowest and the difference was not significant(P<0.05),and the fluidity of layer hens floss samples was higher than that of common broilers.The contents of hydrocarbons,alcohols,ketones,acids,esters and ethers in the volatile substances of broiler floss with ingredients were higher than those of common broiler floss with ingredients,while those of common broiler floss without ingredients were lower.The content of alkanes in meat floss is high.The taste of four kinds of meat floss is different,and there is little difference in the taste of meat floss with ingredients.