【摘要】 【目的】比较真空干燥和真空冷冻干燥对番石榴果粉品质的影响。【方法】采用真空干燥和真空冷冻干燥方法制作番石榴果粉,测定番石榴果粉基本营养成分和理化特性。【结果】真空冷冻干燥果粉的水分、Vc、还原糖、总酸、灰分、粗蛋白基本成分的质量分数分别为41.97 g/kg、6.47 g/kg、251.47 g/kg、10.53 g/kg、5.67 g/kg、24.50 g/kg;真空干燥果粉的水分、Vc、还原糖、总酸、灰分、粗蛋白基本成分的质量分数分别为46.80 g/kg、4.60g/kg、248.27 g/kg、19.97 g/kg、7.00 g/kg、23.76 g/kg;红外光谱检测得到两种干燥方法研制的果粉的主要营养物质种类没有明显差异;真空冷冻干燥果粉为浅绿色偏白,真空干燥果粉为淡黄色;真空干燥果粉的流动性比真空冷冻干燥果粉好,但溶解性和持水性比真空冷冻干燥果粉差;在光学显微镜下,真空冷冻干燥果粉平均粒径为43.71μm,真空干燥果粉平均粒径为141.87μm。【结论】真空冷冻干燥果粉水分含量较低,颗粒较小,分散性、持水性和溶解性较好,并且相对于真空干燥,真空冷冻干燥果粉能更好地保持番石榴原有的色泽风味,品质更优。更多还原

【Abstract】 【Objective】To compare the effects of vacuum drying and vacuum freeze drying on the quality of guava fruit powder. 【Method】Fruit guava powder was prepared by vacuum drying and vacuum freeze drying. The basic nutrients of guava fruit powder were determined according to the Chinese national standard method. The physical and chemical properties were studied by Fourier transform infrared spectroscopy and optical microscopy.【Result】The contents of water, Vc, reducing sugar, total acid, ash and crude protein in vacuum freeze-dried fruit powder were 41.97 g/kg, 6.47 g/kg,251.47 g/kg, 10.53 g/kg, 5.67 g/kg and 24.50 g/kg, respectively. The contents of water, Vc, reducing sugar, total acid, ash and crude protein in vacuum dried fruit powder were 46.80 g/kg,4.60 g/kg,248.27 g/kg, 19.97 g/kg, 7.00 g/kg and 23.76 g/kg, respectively. Infrared spectroscopy results show that there was no significant difference in the main nutrients of the fruit powders prepared by the two drying methods. The color of the vacuum freeze-dried fruit powder was light green and nearly white. The color of the vacuum dried fruit powder is pale yellow. Compared with the vacuum freeze-dried fruit powder,the vacuum dried fruit powder had better fluidity, but the solubility and water holding capacity were poor. Under the optical microscope, the average particle size of the vacuum freeze-dried fruit powder was 43.71 μm, and the average diameter of the vacuum dried fruit powder was 141.87 μm.【Conclusion】The vacuum freeze-dried fruit powder has low moisture content, small particle size,uniform dispersion, good water retention and solubility. It is better in maintaining the original color and flavor of guava, and the quality is better.更多还原