不同干燥工艺对铁皮石斛有效成分及抗氧化活性影响

Effects of Different Drying Processes on Effective Components and Antioxidant Activity of Dendrobium Officinale Kimura et Migo

研究热风干燥、真空干燥、喷雾干燥以及冷冻干燥4种不同干燥方式对铁皮石斛提取物的外观、有效成分及抗氧化活性的影响,为铁皮石斛规模化生产及后期作为化妆品原料开发提供理论依据。冷冻干燥与喷雾干燥的样品颜色比较鲜亮,热风干燥与真空干燥的样品褐变严重;对应各样品中多糖含量无明显差异;而黄酮、多酚含量差异显著;各样品均表现出较强的对DPPH与ABTS清除作用,对于DPPH自由基的清除作用除热风干燥的样品外大体相同,对于ABTS自由基的清除喷雾干燥与冷冻干燥的样品明显优于热风干燥样品。

The effects of hot-wind drying, vacuum drying, spray drying and freeze drying on the appearance, effective componentsand antioxidant activity of Dendrobium officinale Kimura et Migo were studied to provide a theoretical basis for its large-scale produc-tion and the development of cosmetics raw material. The absorbance of Dendrobium officinale was determined by UV spectrophotome-try at the maximum absorption wavelength of the material. The effective content and antioxidant activity were calculated by the absor-bance and standard curve of the sample. The sample which dealt with freeze drying and spray drying was much brighter, and the sam-ple which dealt with hot-wind drying and vacuum drying was browned. There was no significant difference of polysaccharide in thesample which dealt with four methods,but the polysaccharide content of the sample which dealt with spray drying was up to 70 mg/g.Flavonoids and polyphenols were significantly different. The content of flavonoids and polyphenols in spray dried samples was thehighest, which was 1.76 mg/g higher than that in hot air dried samples and 5.66 mg/g in polyphenols. All samples showed strongDPPH and ABTS scavenging effect. The scavenging effect of DPPH free radicals was substantially the same except hot air dried sam-pies, and the spray drying and freeze drying of ABTS free radicals was significantly better than that of hot air dried samples. Dryingprocess will reduce the content of flavonoids and polyphenols in candidum extract and the decrease of DPPH and ABTS free radicalscavenging rate. Different drying process effects are different and spray drying one among four drying processes is the best choice forthe production and preparation of raw materials of dendrobium officinale.