Research Of Chestnut Beverage Processing Technology

Chestnut is rich in nutrition, with starch being the main component of organization, and is rich in protein content and the proteins are rich in amino acids. In addition the chestnut is also rich in vitamins, mineral elements and carotene and other nutrients. Chestnut resources are rich in China, the annual output ranked first in the world, but are at present mainly used for food, few for deep processing. In this study, using chestnut as the main raw material, we adopt the medium temperature amylase enzymolysis chestnut paste of starch, reducing the content of starch in chestnut serosity, and get the enzymolysis liquid; we select walnut powder, sucrose, citric acid to prepare chestnut enzymolysis liquid, and add the relevant stabilizer, and homogenizing and sterilizing preparation process are used to produce chestnut cloudy juice; and we analyze and examine the finished beverages, and study its stability and beverage quality changes during storage. The main results are as follows:1. The result obtained by direct cooking method of chestnut starch, gelatinization, shows that when cooking time is 30min the chestnut kernel appears in golden color, chestnut flavor, pasting the best effect. With the brightness value L as the index of Chinese chestnut paste enzymolysis of color protection in the process of research, it is concluded that using the composite color protecting agent can effectively inhibit the chestnut paste during enzymatic hydrolysis from browning, and we get the chestnut paste during enzymatic hydrolysis of the best protection formula through orthogonal experiment:0.06% citric acid, sodium ISO VC 0.025% and EDTA-2Na0.03%. The value of L of Chinese chestnut paste after enzymatic hydrolysis conditions of is 53.49, the L value without adding chestnut paste enzyme composite color fixative solution is only 44.31.2. Using the middle temperature alpha amylase enzymolysis technology to enzymolyse chestnut starch paste, we study the effects of enzymolysis temperature, ratio of material to liquid, enzymolysis time, enzyme dosage on chestnut starch liquefaction DE value and optimization of enzymatic hydrolysis process. Through orthogonal test the optimal hydrolysis conditions are obtained:enzymolysis temperature of 60℃, the material liquid ratio of 1:4, the quantity of the enzyme 7U/g, hydrolysis time 90min, chestnut paste DE value under the condition of enzymatic hydrolysis 47.91%. After enzyme hydrolysis, the soluble solids content, reducing sugar of Chestnut paste increased, but starch reduced significantly, starch hydrolysis rate is as high as 85.84%.3. We use chestnut enzyme solution as the main ingredients for beverage mixing to obtain better sensory effect. It is obtained by orthogonal test that the best formula for chestnut cloudy juice as:chestnut paste of enzyme solution added 50%, adding 0.04% citric acid, sucrose 8%, walnut powder adding quantity 1.5%.4. Taking water holding capacity and sensory evaluation as the main index, optimization is done on chestnut cloudy juice stability and sterilization process. Through a single hydrophilic gum and emulsifier test, we screened carrageenan, CMC-Na, PGA, polyglycerol ester as compound stabilizers for chestnut cloudy juice beverage, and the best formula was determined by orthogonal test:CMC-Na addition 0.10%, carrageenan addition 0.15%, polyglycerol ester additive content 0.03%, PGA 0.06% addition. The optimum conditions of homogenization are:homogeneous temperature of 60℃, homogenization pressure 40MPa, the 3 homogeneous times, under this condition the water holding capacity up to 86.12% drinks. UHT sterilization is chosen as the sterilization condition of the beverage, namely, temperature 135 C, time 4s.5. Chestnut cloudy juice paste are uniformed and stable and the color is light yellow and bright, fragrance, the taste is smooth and full, moderate in sweet and sour. Microbial indicators meet the requirements of GB/T4789.21; the protein and fat content is high and the nutrient rich in the beverages. Beverage storage stability and studies show that:with the increase of storage time the state, water holding capacity, and L values decline in different degrees The higher the temperature, the index of beverage decreased more quickly, which suggests that the long-term preservation at high temperature is not conducive to drink. But research on beverage quality show that:with the increase of storage time, under 4℃ storage condition the hardness increased, and the smoothness, cohesion, coefficient of viscosity and sensory scores decreased; under 25 ℃,36℃ storage conditions the beverage hardness, smoothness, cohesion, viscosity coefficient and sensory score decreased in different degrees. The higher the temperature is, the more decrease of each index. This indicates that the long time high temperature storage is not benefit for beverage quality.