Qiu Liqing, Zhang Min, Bhandari Bhesh, Wang Bin
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.
International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China.
J Sci Food Agric. 2020 Oct;100(13):4791-4800. doi: 10.1002/jsfa.10538. Epub 2020 Jun 23.
Infrared freeze drying (IRFD) utilizes infrared radiation as a novel heating source in freeze drying (FD), leading to high-quality dehydrated products and less drying time. The present study aimed to investigate the effects of IRFD on the drying characteristics (drying time and energy consumption), volatiles, physical structure and nutritional properties of Rosa rugosa flower. In addition, freeze drying (FD) and hot air drying (HAD) were also evaluated in a comparison with the IFRD drying method with respect to product quality parameters.
Fifty-six volatile compounds were identified in fresh samples, whereas 53, 51 and 46 volatile compounds were identified in FD, IRFD and HAD samples, respectively. FD and IRFD were relatively more effective than HAD for better retention of volatile compounds of Rosa rugose flower. E-nose analysis also exhibited similar flavor properties in FD and IRFD samples. The molecular structure properties of FD and IRFD samples measured by FTIR spectroscopy were also similar. As for nutritional properties, HAD dramatically (P < 0.05) reduced the nutritional values of R. rugosa flower after drying. The content of vitamin C (from 14.83 to 12.15 mg 100 g ), flavonoids (from 478.00 to 333.33 mg 100 g ) and anthocyanins (from 220.70 to 196.90 mg 100 g ) in R. rugosa flower is well retained by IRFD and no significant difference (P < 0.05) was observed between FD and IRFD samples.
IRFD was found to be effective in retaining the aroma, structure and nutrition of R. rugosa flower, as well as demonstrating a lower energy consumption and shorter drying time. © 2020 Society of Chemical Industry.
红外冷冻干燥（IRFD）在冷冻干燥（FD）中利用红外辐射作为一种新型加热源，可得到高质量的脱水产品且干燥时间更短。本研究旨在探究红外冷冻干燥对玫瑰鲜花的干燥特性（干燥时间和能耗）、挥发性成分、物理结构及营养特性的影响。此外，还将冷冻干燥（FD）和热风干燥（HAD）与红外冷冻干燥法在产品质量参数方面进行了比较评估。
在新鲜样品中鉴定出56种挥发性化合物，而在冷冻干燥、红外冷冻干燥和热风干燥样品中分别鉴定出53、51和46种挥发性化合物。冷冻干燥和红外冷冻干燥在保留玫瑰鲜花挥发性化合物方面比热风干燥更有效。电子鼻分析也显示冷冻干燥和红外冷冻干燥样品具有相似的风味特性。通过傅里叶变换红外光谱（FTIR）测定的冷冻干燥和红外冷冻干燥样品的分子结构特性也相似。至于营养特性，热风干燥显著（P<0.05）降低了干燥后玫瑰鲜花的营养价值。红外冷冻干燥能很好地保留玫瑰鲜花中维生素C（从14.83降至12.15mg/100g）、黄酮类化合物（从478.00降至333.33mg/100g）和花青素（从220.70降至196.90mg/100g）的含量，且冷冻干燥和红外冷冻干燥样品之间未观察到显著差异（P<0.05）。
发现红外冷冻干燥在保留玫瑰鲜花的香气、结构和营养方面有效，且能耗较低、干燥时间较短。©2020化学工业协会。
