不同干燥方式对葛根全粉抗氧化性能和香气成分的影响

以葛根为原料,研究热风干燥、冷冻干燥、真空干燥对葛根全粉的基本成分、抗氧化性能和香气成分的影响。结果表明:不同干燥方式下葛根全粉的淀粉、粗蛋白、粗脂肪等基本成分含量差异显著(P0.05),冷冻干燥葛根全粉中总黄酮和总酚含量分别为2.46 g/100 g和1.37 g/100 g,显著高于其他2种干燥方式(P0.05);冷冻干燥所得葛根全粉的自由基清除力、还原力和金属离子螯合能力最高,而热风干燥所得产品的抗氧化能力最低。运用固相微萃取-气相色谱-质谱联用对鲜葛根和3种干燥方式葛根全粉的香气物质进行分析,鲜葛根、热风干燥、真空干燥和冷冻干燥全粉各自鉴定出43、68、66种和64种挥发性香气成分。真空干燥和冷冻干燥对于鲜葛根中的香气成分有更好的保留和增加效果,并且减少了部分对风味有反作用的物质。

Effect of Different Drying Methods on the Antioxidant Properties and Aromatic Composition of Whole Flour from Pueraria lobata Roots

The influences of hot air drying, freeze drying and vacuum drying on the basic components, antioxidant properties and aromatic composition of whole flour from Pueraria lobata roots were studied. The results indicated that the contents of starch, protein, fat and other basic components in flours produced by different drying methods were significantly different (P < 0.05). The contents of total flavonoids and total phenolics in the flour prepared by freeze drying were 2.46 and 1.37 g/100 g, respectively, which were significantly higher than those obtained by the other drying methods (P < 0.05). The free radical scavenging activity, reducing power and metal ion chelating ability of the flour prepared by freeze drying were found to be the highest. On the other hand, the antioxidant capacity of hot air dried flour was the lowest. Analysis by solid-phase micro extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) showed that a total of 43, 68, 66 and 64 volatile aromatic components were identified in fresh Pueraria lobata roots, and hot air dried, vacuum dried and freeze dried flours, respectively. This study found that vacuum drying and freeze drying provided better retention and even enhancement of the aroma components in fresh Pueraria lobata roots, while reducing some components contributing negatively to the flavor.