干燥技术对玛咖品质的影响

Effects of Drying Technologies on the Quality of Maca(Lepidium meyenii walpers)

为进一步提高玛咖干燥效率和品质,本研究主要考察并优化了干燥前处理、干燥时间和干燥温度等工艺参数。结果表明,经蒸制或高温热风杀青处理后再干燥,玛咖的外观品质和营养成分含量(可溶性浸出物、淀粉、蛋白质和多糖)显著降低。玛咖的最佳干燥工艺为:在30℃条件下干燥30 h后,以每6 h升温2℃的速度升至48℃,再以每6 h升1℃的速度升至55℃,直至玛咖含水率≤13%,总耗时126 h。以该工艺干燥所得玛咖外观色泽好,整体形变小,表皮褶皱浅。蛋白质、花青素和多糖的含量分别为6.60%、1.42%和3.57%。

The process parameters such as pre-treatment process, drying time and temperature were investigated and optimized in order to improve the drying efficiency and quality of Maca. The results showed that the appearance and nutrient contents （such as soluble extract, starch, proteins and polysaccharides） of dry Maca were decreased significantly after pretreated with steaming or high temperature wind fixing process. The optimal drying process was as follows： Maca was dried at 30℃ for 30 h, and then the temperature was raised to 48 ~C at the speed of 2 ℃/6 h, then raised to 55 ℃ at the speed of 1 ℃/6 h, until the moisture content of Maca was no more than 13%. The whole process totally took about 126 h. Under the above process, the color of dry Maca was bright, with less deformation, and the fold was shallow. The contents of protein, anthocyanin and polysaccharide were 6.60 %, 1.42 % and 3.57 %, respectively.