热力干燥中热湿不稳定物质质量的保护

生物物料和食品在热力干燥过程中的质量退化主要是由其热湿不稳定特性导致的。因此为保持干燥后产品的质量，常采用较温和的干燥条件，以及减少物料在高含水率阶段的干燥时间。为观察其对物料品质指标的影响，对面包酵母和清蛋白两种物质在不同的干燥条件下进行了热力干燥试验。结果显示：欲获得更好的热力干燥后产品品质，对热、湿耐受性不同的生物物质应采用不同的保护措施。

Protection of Thermo-and Xero-labile Materials during Thermal Drying

Degradation of biomaterials and foods during thermal drying is caused mainly by their thermo-and xero-labile properties. Therefore both non-intensive temperature procedure and shorter treatment time (especially in the period when moisture content is still high for xero-labile materials) applied in processing are suggested to enhance quality retention. To observe the influences of the above two measures on material quality indexes, two types of materials, baker's yeast and albumin, were thermally dried under various operating conditions. The results showed that different methods should be applied for biomaterials with different thermal properties to obtain better quality retention during thermal drying.