Study On Spray Drying Processing Technique Of Fast-dissolving Chestnut Powder

Chestnut is rich in a lot of nutrition. To raise the level of chestnut processing and supply the internal and overseas need, chestnut of Qianxi was used as the raw material, this subject chose a relatively economical and advanced technique-spray drying as the method to process chestnut powder and analyzed the results of the experiments, which can provide some experimental instruction and technical support for the manufacturing of chestnut powder by spray drying. The product of fast-dissolving chestnut powder can meet the demands of quick rhythm today. It is important to speed up agriculture industrialization of our nation. By the experiment, the technology of color-protecting and the reasonable amounts of additive was affirmed. Finally, the optimum condition of spray drying of the chestnut powder had been defined. The main aspects and the results were represented as follows:1. The color-protecting technologyThe optimum concentration of Citric acid,Ascorbic acid,Chitosan and Sodium chloride on color-protecting were studied by the single factor experiment firstly. Secondly, the best concentration of Citric acid, Ascorbic acid, Chitosan and Sodium Chloride on color-protecting were determined by L₉(3⁴) orthogonal experiment, which were 0.25%, 0.25%, 0.20 % and 0.35%. This result could effectively restrain browning of chestnut powder.2. The stability technology of chestnut powderThe best condition of improving stability were CMC-Na 0.20%, Xanthan gum 0.25%, Distilled glycerin monostearate 0.40%,Sucrose fatty and ester 0.45%.The Fast-dissolving chestnut powder had best stability on this condition.3. The selection of drying aidsTaking the soluble starch,β-Cyclodextrin and the maltodextrin as drying aids selected, the maltodextrin andβ-Cyclodextrin were selected as drying aids during spray drying by single factor experiment ,which the addition were 50% and 10%.The drying aids could effectively improve the effects of spray drying.4. The selection of condition of homogenizationThe condition of homogenization has great significance on stability of chestnut powder. Through the single factor experiment, the optimum condition of homogenization was temperature of homogenization 60℃and pressure of homogenization 20 MPa. 5. The selection of fast-dissolving aidsThe fast-dissolving foods must have well dissolving in order to dissolve quickly in liquid. The chestnut powder had best fast dissolvability when the concentration of Lecithin was 2.5%.6. The spray drying technologyThe powder yield, content of water and score of dissolving were took as indexes, the optimum condition of spray drying of the chestnut powder had been defined by the single factor experiment and L₉(3⁴) orthogonal experiment. The results as follows: inlet temperature 135℃, the soluble solids 18Brix,the drying air quantity 0.8m³/min, the feeding rate 4.0×180mL/h.