淮山片真空冷冻干燥工艺的优化

Optimization of the vacuum freeze drying process of Chinese yam slices

目的改进淮山片真空冷冻干燥工艺的参数。方法以鲜切淮山片为材料,采用电阻法测量淮山的共晶点和共熔点温度。通过汁液流失率、复原率、中心温度和含水量检测,研究预冻和升华干燥工艺。通过正交试验和复原率、口感测定,确定淮山鲜切片的浸护处理方案。结果鲜切片在95℃水浴锅中烫漂60 s后,采用"Na Cl 5%+麦芽糊精10%+葡萄糖15%"浸护液浸泡30 min,其真空冷冻干燥产品复原率可达83.27%,复水后口感较好,产品在整个加工过程中未变色。厚度为5~6 mm的淮山鲜切片共晶点为-20℃,共熔点为-18℃,淮山片升华干燥时间耗时16 h。结论本试验建立的方法得到的淮山片复原率高,口感好,为淮山片的加工工艺提供技术支持。

Objective To optimum technology parameters of vacuum freeze drying of Chinese yam slices. Methods Fresh cut yam slices were used as materials, the eutectic point and co-melting point of the yam slices were determined by electric resistivity method. Through determination of juice leakage, recovery rate, center temperature and moisture content, the pre freezing and sublimation drying process were studied. Through the orthogonal experiment and determination of the recovery rate and taste as indexes, fresh yam slices soaking treatment was established. Results The fresh slices were heated in 95 ℃ water bath for 60 s, then soaked with ＇5% NaCl＋10%maltodextrin＋15% glucose＇ for 30 min. Under these conditions, the recovery rate of vacuum freeze drying products was up to 83.27%. After rehydration, the taste was better, and the yam slices did not change color during the whole process. The eutectic points of 5-6 mm yam slices was -20 , and℃ the co-melting point was -18 . It took 16 h to℃complete sublimation drying of yam slices. Conclusion The Chinese yam slices prepared by the established method have high recovery rate and good taste, which provides technical support for the processing of Chinese yam slices.