| The demand for pet food is increasing with the development of my country’s economy.The semi-dry pet food produced with chicken breast is cheap and proteins.It has a good nutritional supplement for pet and occupies an important position in the pet food industry.However,the shelf life of semi-dry pet food is relatively short,and lipid oxidation and discoloration will prone to occur during storage.At present,few studies have been done according to the quality change and shelf life of semi-dry pet food.Therefore,in this study,chicken breast and dried sweet potatoes were used as raw materials to design a semi-dry pet food.The effects of product formula,storage temperature,packaging methods,and hot air-drying conditions on the quality and shelf-life of this chicken breast-sweet potato dry pet food were elucidated.The results provide theoretical guidance for the production of high quality pet food.The main results were as follows:The optimal formula proportion was finalized based on the quality,sensory evaluation,and color catachrestic of the product with glycerol of 5%,compound phosphate of 0.5%,peanut protein of 4% and cassava starch of 1.5%.On this condition,the product showed 0.57 moisture activity and higher sensory evaluation.Moreover,it was found that product with this formula have more ideal product appearance and longer shelf-life compared with the enterprise products.The effect of three drying temperatures(55℃、65℃ and 75℃)on product quality were studied.It was found that the higher the temperature,the higher the a*value of the product and the lower the L* value,which means that the product has a darker color and fat.The degree of oxidation is serious.Comparing and analyzing the three temperatures,it is found that when the moisture content of the product is 20%,it only takes 7 h under 75℃ and 13 h under 55℃.Obviously,the product takes less time and the drying rate is fast under 75℃,but the product The color is deep and the quality is low,but the product under the condition of 55℃ maintains better color and quality.The effects of different storage temperatures(7℃、25℃ and 37℃)on the quality and shelf-life of the products were studied.Compared with 25℃ and 37℃ groups,the low temperature of 7℃ group showed more brighter color,lasting meat flavor,lower lipid oxidation,and extended shelf-life.In addition,accelerated storage experiment with 60℃ and antioxidant experiment were conducted.It was found that the BHA could partly inhibit browning and lipid oxidation,in the same storage period,the shelf life of BHA-added products can be extended by ten more days and maintain good quality and color.The effect of vacuum packaging and non-vacuum packaging on quality and shelf-life of pet products were investigated.It is found that compared with non-vacuum packaging,vacuum packaging can inhibit the growth and reproduction of microorganisms,delay the degree of lipid oxidation,and in the same storage period,vacuum packaging is 20 days longer than non-vacuum packaging,and the vacuum packaging method achieves the purpose of prolong the shelf-life of the product. |
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