干燥方式对高良姜片理化特性的影响

Effect of Drying Methods on Physicochemical Properties of Alpiniaofficinarum Hance Slices

目的:探究高良姜片干燥前后理化特性的变化情况,确定最佳保质干燥方式。方法:采用色差仪、紫外分光光度仪、高效液相色谱仪、固相微萃取-气相色谱-质谱联用仪考察6种干燥方法对高良姜片色泽、总酚含量、总黄酮含量、高良姜素含量、挥发性成分的影响。结果:冷冻干燥对总酚、总黄酮和高良姜素的综合保留最大,分别为总酚(20.95±0.13)mg/g、总黄酮(12.19±0.01)mg/g、高良姜素(11.45±0.03)mg/g,其次为真空加热干燥、热风干燥、微波干燥、太阳晒干、自然风干;自然风干和太阳干燥后的挥发性物质峰面积更低,其他4种干燥方式峰面积统计值差别较小;微波干燥后色泽最深,红绿值a*为13.92,热风干燥次之,冷冻干燥颜色最浅。结论:不考虑成本生产高端产品时可选用冷冻干燥;考虑环保节能时选用太阳能干燥;一般工业生产建议选用传统热风干燥。

Objective: To explore the physicochemical properties of fresh and dried galanga (Alpinia officinarum Hance) slices, and to further establish a drying method for the maximum retention of bioactives. Methods: The contents of total phenols and flavonoids in galanga slices were determined by a spectrophotometer, galangin was quantitated by high performance liquid chromatography, the volatile components were measured by gas chromatography, and the color was evaluated by a colorimeter. Results: The abilities of different drying methods to retain total phenols, total flavonoids and galangin were in the decreasing order of freeze drying > vacuum drying > hot air drying > microwave drying > sundrying > shade drying. The contents of total phenols, total flavonoids and galangin in freeze-dried samples were (20.95 ± 0.13),(12.19 ± 0.01), and (11.45 ± 0.03) mg/g, respectively. In terms of peak area, volatile components were lower in theshade-dried and sun-dried samples. On the other hand, the four other drying methods differed little from each other. Themicrowave-dried galanga had the deepest color with a* value of 13.92, followed by hot air drying, and the color of freezedriedwas the lightest. Conclusion: Freeze drying can be used to produce high-quality products without concern about cost.Sun drying is available for environmental protection and energy saving. The traditional hot air drying is recommended for routine industrial production.