【摘要】 以半干骏枣为原料,采用太阳能干燥和真空冷冻干燥分别对枣块和枣浆进行单一干燥和联合干燥,并对干燥后得到的枣粉进行感官评价及营养成分测试分析。综合感官评价与干燥特性,结果表明:太阳能干燥的最佳枣块厚度为4 mm;真空冷冻干燥枣块和枣浆的最佳实验条件为真空度10 Pa、枣块厚度和枣浆液体高度均为6 mm、搁板温度均为45℃;太阳能-真空冷冻联合干燥枣浆的最佳实验条件为先利用太阳能将20%质量分数、液体高度为4 mm的枣浆干燥至浓度为(30±1)%,再进行真空冷冻干燥,加热搁板温度为55℃、真空度10 Pa。营养成分测试结果表明:最佳实验条件下,太阳能-真空冷冻联合干燥枣浆得到的枣粉总糖含量最高,真空冷冻干燥枣块得到的枣粉Vc保留率最高。更多还原

【Abstract】 In this experiment, semi-dry jujube was used as raw material to be made into jujube powder by solar drying and vacuum freeze-drying separately and jointly. Sensory evaluation and nutrient composition test of dried jujube powder were analyzed after the experiment. The results of comprehensive sensory evaluation and drying characteristics showed that the best thickness of jujube blocks for solar drying was 4 mm; the best experimental conditions for vacuum freeze-drying of jujube blocks and jujube pulp were vacuum degree being 10 Pa, thickness of jujube blocks and liquid height of jujube pulp being both 6 mm and shelf temperature being 45 ℃; the best experimental conditions for solar-vacuum freezedrying of jujube pulp were as follows: firstly, jujube pulp whose liquid height was 4 mm was dried from the concentration of 20% to(30±1)% by solar drying, then continued to be dried with shelf temperature of 55℃ and vacuum degree 10 Pa in the vacuum freeze dryer. The results of nutrient test showed that the total sugar content of jujube powder obtained by solar-vacuum freezing of jujube pulp was the highest, and the retention rate of Vc was the highest in jujube powder obtained by vacuum freeze-drying.更多还原