| Purple sweet potato also called black potato. Purple sweet potato is rich in nutrition and contains many kinds of biological active substances. Often edible purple sweet potato can significantly enhance the body's immune ability, it can anti-cancer. But the purple potato harvest period is short, not year-round, and the purple sweet potato's moisture content is high, easy to suffer the mechanical damage and insect pests and diseases, easy to rot, not easy to transport and storage, which greatly limits the processing and application of purple sweet potato. Not only has the huge economic loss to the farmers planted purple sweet potato. but also the enthusiasm of the farmers to plant purple potato. Is also a great waste of resources for quality agricultural products. Therefore it is urgent to broaden the way of purple sweet potato production's application and processing methods. Development of a new type of purple sweet potato products, improve product added value can reduce the risk of the existence of the enterprise, and improve the market strain capacity, so as to obtain the economic benefits of stability. In this study, using fresh purple sweet potato as the main raw material, through process optimization and optimization of the formula developed a chips, which is crisp, sweet, has low oil content and high anthocyanin content. At the same time, predict the shelf life of the product. To provide a new way for the development and utilization of purple sweet potato.The main research contents and results of this paper are as follows:1. The influence of different processing technology on quality characteristics of composite purple sweet potato chipsThe effect of frying, microwave and baking on the quality characteristics of purple sweet potato chips was studied in this part. Comparison of different processing of composite purple sweet potato chips texture, puffing degree and color, anthocyanin content and sensory score. The results showed that the best processing technology of composite purple potato chips was frying process. Its crispness and hardness were 225.5 and 1030.8, the swelling degree was 112.64%, the color value of L*=43.19, a*=20.23, b*=-0.59, the anthocyanin content was 110.842mg/100g.2. The optimization of purple sweet potato crisps recipeThis part studies the optimum formula of composite purple potato chips. Sensory evaluation indicators, The basic formula of the composite purple potato chips obtained by single factor test, corn starch addition amount was 20%, sugar added to 10%, soybean protein isolate by adding 2%. Again to sensory evaluation index, through orthogonal test further the formula optimization, get the best formula of the composite purple sweet potato chips, namely corn starch addition was 25%, sugar addition dosage of 7.5%, soybean protein isolate was 1.5%, its sensory score for 92.35.3. Process optimizationIn this part, the optimal process parameters of frying process were studied. Quality structure, color, oil content, anthocyanin content as the index, through the single factor experiment, determine the basic parameters for drying time was 60min, fried temperature of 150?, fried time is 30s. Again with oil content and anthocyanin content as evaluation index, using box Behnken design is optimized further fried process parameters, get fried composite purple sweet potato chips optimum parameters for drying time was 58 minutes, frying temperature 145?, fried time 25s and obtained composite purple sweet potato chips products was violet, pleasant aroma and the oil content, anthocyanin content respectively for 26.021g/100g,161.427mg/100g.4. Shelf life predictionThis part studied the storage time of composite purple sweet potato chips. Under the different temperature of acid value and peroxide value with the change of time to measure the degree of deterioration of oil compound of purple sweet potato chips. The results show that using the acid value as an index, the shelf life at 25? was 63 days; Using peroxide value as an index, the shelf life at 25? was 58 days. |
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