Study On The Influence Of Different Processing Technology On The Quality Of Concentrated Soup Of Spent Hen

Among the livestock and poultry meat, the spent hen accounts for a large proportion in the total output. The muscles of these hens have high content of connective tissue and poor tenderness, whose meat quality is aged. The product is difficult to chew and cook. Meanwhile the residue is too much. But the analysis result of the unconventional nutrients shows the hens with high protein, low fat, low cholesterol and low ash. Therefore, the nutritional composition fit to people’s consumption demand. For the purpose of enrichment of spent hen soup industrialized production, this paper takes the spent hen as research objects and studies on the optimization of boil, enrichment, allocation and drying. The major researches and experimental results were as follows:First, the atmospheric pressure boiling process and high pressure boiling process was studied. The test studied the effects of different boiling process on the physical and chemical indicators and sensory evaluation of chicken soup through single factor experiment. Choose the 4h boiling chicken soup and the 60min high pressure boiling soup for comparison again. The results showed that atmospheric boiling chicken protein content, amino nitrogen content and collagen content was significantly higher than the high-pressure boiling chicken broth (P<0.05). In the evaluation of fat oxidation, the peroxide value, TBARS values and the measured acid value case, the pressure boiled chicken broth were significantly higher than the high-pressure boiled soup (P<0.05); Pressure and high pressure boiled integrated sensory evaluation scores were 35.5 and 31.6, atmospheric boiling chicken broth in aroma, taste, consistency and acceptability aspects were significantly better than high pressure boiling (P <0.05), and it has rich aroma, mellow taste. Considering the nutritional value and taste of chicken broth, boiled 4h determined to be the best boiling process.Then the atmospheric concentration and concentrated in vacuo of conditions were studied. The measurement results of the physical and chemical showed that the sugar and amino acid nitrogen values of atmospheric concentrated were significantly lower than chicken broth concentrated under vacuum values (P<0.05). Meanwhile, among several physical and chemical indicators which reflected chicken broth oxidation,peroxide value, acid value and TBARS values, the pressure cooker concentrated values were also significantly greater than that of vacuum concentrated. Compare with the fat content and collagen which affected the consistency and flavor of chicken broth, concentrated under vacuum values significantly lower than atmospheric pressure cooking concentrate. The sensory evaluation results showed that the vacuum concentrated score better than concentrated at atmospheric pressure cooking on color appearance. While in the aroma, taste, consistency and acceptability, concentrated under vaccum were lower than atmospheric pressure cooking concentrated. Considering of physicochemical and sensory evaluation results, the best way of concentration is pressure cooking concentrated.In order to make a better flavor of the final product, the experiment determine the allocation of chicken broth recipe by orthogonal experiment. Choose salt, sugar, carrageenan, chicken four facotors which impact greater on the flavor first single factor experiments, on this basis conducted four factors and three levels orthogonal experiment. On the standard of sensory evaluation score, the four factors concentrated in the order of: salt>chanterelles>sucrose>carrageenan. Meanwhile, Duncan multiple comparison determined the optimal level of four factors, and combinations to make a verification test, ultimately determine the best solution for the deployment of 0.3% saline,0.2% sucrose,0.2% carrageenan,5% chicken fat;Finally, two kinds of drying process were compared.By moisture content and solubility index contrast. The results showed that freeze-dying significantly better than boiling dry. Compare with the sensory evaluation scores, the vaccum freeze-dried chicken broth were significantly better than boiled drt in color, aroma, taste, consistency and acceptability. So determine the freeze-drying process as the best processThe study shows that, choosing atmospheric boiling way to cook spent hen. After 4h boiling, cooling, filtration and separation chicken fat, concentrating the soup to a solids content of 32% with pressure cooking mode. Then allocate the soup in accordance with 0.3% salt,0.2% sucrose, 0.2% carrageenan,5% chicken fat. Finally dry the soup with freeze-drying method. The resulting quality of the final lyophilized product is:fat content of 87.40%; protein content of 29.96%; amino nitrogen content of 0.156g/100ml; sugar is 45.2mg/100g. The total number of colonies and coliform group were not tested exceeded.