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中国农学通报

中国农学通报 ›› 2011, Vol. 27 ›› Issue (4): 356-360.

• 食品 营养 检测 安全 • 上一篇    下一篇

荔枝真空冷冻干燥关键技术

陈仪男 郭树松 郭建辉 林龙生 吴秀秀   

  • 收稿日期:2010-09-03 修回日期:2010-10-25 出版日期:2011-02-10 发布日期:2011-02-10

The Key Technologies of Vacuum Freeze-drying of Litch Fruits

  • Received:2010-09-03 Revised:2010-10-25 Online:2011-02-10 Published:2011-02-10

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摘要：

为了确定荔枝真空冷冻干燥工艺关键技术参数，以成熟的‘乌叶’荔枝为材料，采用电阻法测量荔枝果肉的共晶点和共熔点温度，通过考察冻干品色泽比较不同护色剂的护色效果，以冻干生产能耗、总冻干时间及冻干品外观形态与色泽等指标进行综合评定冻干效果，优选荔枝真空冷冻干燥工艺关键技术参数。结果表明：荔枝真空冷冻干燥物料的共晶点温度、共熔点温度分为-26℃和-17℃，采用“0.6%柠檬酸”单一护色剂或“0.4%柠檬酸+0.2%维生素C”复合护色剂浸泡20 min，对荔枝冻干品有良好护色效果。冻干过程起始板温控制在80℃以下，升华阶段物料最高温度设定为55℃，升降温期干燥仓真空值组合选择60~70 Pa/60~70 Pa，可节省冻干生产能耗、缩短总冻干时间，同时能改善冻干品的外观形态与色泽。

关键词: 杀配子染色体, 杀配子染色体, 小麦, 黑麦, 异代换系

Abstract:

In order to confirm the key technology in vacuum freeze-drying of litch, experiments were conducted with litch cultivar ‘Wuye’. The eutectic point and the consolute point of litch were determined by electrical resistance method in the vacuum freeze-drying. The different color fixative agents were compared on their color-protecting effects by analysis the color of the freeze-drying products. The key technical parameters of the vacuum freeze-drying of litch were optimized with the freeze-drying effects of the comprehensive indexes being evaluated by energy consumption, freeze-drying time, appearances shape and colors of the products during the process of vacuum freeze-drying. The results showed that the eutectic point and the consolute point of lithc’s pulp materials were -26℃ and -20.0℃ in the vacuum freeze-drying, respectively. In the solution of 0.6% citric acid or 0.4% citric acid + 0.2%VC with immersing time for 20 min were gaven the best color-protecting effects. At the condition of first drying temperature under 80℃, material maximum temperature of 50℃during sublimation stage, and the combination of the vacuum value in drying chamber ranged from 60 Pa to 70 Pa/from 60 Pa to 70 Pa, could save the energy consumption, shorten the freeze-drying time and improved the appearances shape and color of the vacuum freeze-drying products.