Effects of Different Drying Methods on Physico-Chemical Properties of Dendrobium Officinale
Qingran Meng1,3, Haoran Fan1,3, Shimin Ji1, Jing Li1, Lianfu Zhang1,2,3
1. School of FoodScience and Technology, Jiangnan University, Wuxi, 214122 China
2. National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, 214122 China
3. State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122 China
2. National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, 214122 China
3. State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122 China
Abstract—Dendrobium officinale has been used in China for several thousand years as a health food and a source of nutrients. The aim of this study was to investigate the effects of different drying methods on the characterization of D. officinale. The physico-chemical properties, i.e color retention, shrinkage rate, functional components contents, moisture sorption isotherms and FTIR spectrum of D. officinale samples through sun drying (SD), oven drying (OD), vacuum drying (VD), infrared radiation drying (ID) and freeze drying (FD) were investigated. The results revealed that different drying methods showed significant difference on color retention, shrinkage rate and water soluble polysaccharides content of D. officinale, but not total dendrobine or protein content. As can be seen from the FTIR spectra, no new chemical bonds were produced between different dried D. officinale samples. In the same water activity, the moisture content in freeze dried samples at equilibrium was slightly higher compared with other four samples. FD samples presented the best quality in color and shrinkage protection, but with respect to the water-soluble polysaccharides content for D. officinale, OD, VD and ID samples were better than FD samples, and OD ones was the highest. The results showed that the quality of dried D. officinale depends on the drying method and conditions. Considering the retention of polysaccharide content, OD is considered promising for drying D. officinale.
Index Terms—Dendrobium officinale, Different drying methods, Physico-chemical properties
Cite: Qingran Meng, Haoran Fan, Shimin Ji, Jing Li, and Lianfu Zhang, "Effects of Different Drying Methods on Physico-Chemical Properties of Dendrobium Officinale," International Journal of Food Engineering, Vol. 3, No. 1, pp. 35-41, June 2017. doi: 10.18178/ijfe.3.1.35-41
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