Research On The Influence Of Drying Technology And Storage Conditions On Apple Powder Quality

Apple is one of the main fruit varieties in our country. Even the annual output takes the first place in the world, processing and conversion rate is lower than the world average. Major processed products are apple juice concentrate. Compared with other processing apple products, apple powder is easy to transport, storage, and keep the original nutrition, apple flavor, increase the storage period of the product. Apple powder is adaptable, it can be added in the nutrition health care products, flour products, infant food, meat products, solid beverage, instant food, dairy products and other foods as the basic material, can improve the sensory and nutritional quality of food. However, the drying technology for apple powder is maturity, product quality is not stable. Further study of apple raw materials, drying technology, the influence of storage conditions on apple powder quality, is the way to promote high quality apple powder and production technology to be widely used, increasing utilization degree of apple processing. Based on apple variety resources, this study start with the apple powder drying technology, focus on the central task of apple powder processing quality and storage quality control. This research studies the apple varieties, drying method and the influence of storage conditions on apple powder quality, discusses the technical measures to control apple powder quality. Main results and conclusions are as follows:1. The influence of varieties on apple powder quality: the influence of Red Fuji, Starkrimson, Generally Red, Big GuoGuang, Golden Marshall, Ga La six varieties of apple milling experiments of apple and apple powder was determined and the physical and chemical properties. Fuji pulverizing results show that total phenol content, the instant sex, color, sensory quality is better suitable for apple powder pulverizing varieties.2. The influence of drying methods on the quality of apple powder: the quality of apple powder different with drying temperature and drying time, high temperature and drying time will cause the loss of nutrients and color deepened. The content of polyphenols, flavonoids both show a significant positive correlation with the ability of scavenging free radicals. Flavonoids showed strongest antioxidant capacity, followed by polyphenols.3. The adsorption curves of apple powders could be best fitted by GAB model. The equilibrium moisture content increases with increasing water activity; decreases with increasing temperature. The glass transition temperature declines with increasing equilibrium moisture content. At 40oC, the critical water contents of β-cyclodextrin, corn starch, maltodextrin were 0.0745g/g, 0.0137g/g, 0.0032g/g; while the critical water activity of β-cyclodextrin, corn starch, maltodextrin were 0.1795, 0.0159, 0.0106, respectively. The storage temperature of apple powder with the addition of soluble starch should not be more than 17 oC. The results will provide valuable inform ation for selecting drying methods and establishing optimum storage conditions of apple powder.