文摘
In this study, response surface methodology was used to optimize parameters of short- and medium-wave infrared drying processing for producing jujube powder. Optimization factors were power input (675-,575?W), drying temperature (70-0?°C) and drying time (2.5-.5?h), and responses were moisture content, L value, b value and vitamin C content of the jujube powder. Box–Benhnken center design was applied to the optimized the processing conditions. The optimal conditions for the production of jujube powder by the short- and medium-wave infrared drying method were power input of 1,125?W, drying temperature at 85.4?°C and drying time for 3.5?h. Under the optimal conditions, the values of moisture content, L, b and vitamin C content of jujube powder were 4.59?%, 64.46, 19.87 and 441.56?mg/100?g, respectively. Quality evaluation of the jujube powder was also investigated. The results were: hygroscopicity of 28.83?%, rehydration of 236.44?%, solubility of 53.59?%, bulk density of 0.70?g/ml, particle size of 154.2?μm, soluble solids content of 82.29?%, total sugar content of 46.87?%, reducing sugar content of 32.09?%, total acid content of 2.03?%, total flavonoids content of 1.45?% and cyclic adenosine monophosphate content of 75.32?mg/kg. The microstructure of jujube powder was irregular and 38 kinds of aroma components were generated.