Abstract

Three methods of shade (MI), open sun (MII) and new designed of solar (MIII) drying were used for peppermint dehydration. The air velocity (u) and temperature (T_d) of MI, MII and MIII were 0.5, 0.5, and 1.5 m/s and 32, 36, and 48 °C, respectively. The energy utilization efficiency, T_d/u ratio and drying rate of MIII reached 85%, 48 °C.s.m⁻¹ and 12.5 g_H2O/min, respectively, which were higher than those in MI and MII. The inhibition power of dried peppermints against 6-log colony forming unit/ml of Staphylococcus aureus (Sa) were also evaluated. While the chlorophyll and essential oil extraction efficiency of MIII-product were 30% and 60% respectively higher than those in MII-product, its total phenolic contents and antioxidants activities were 25% and 26% more than those in MI-product. The essential oil of MIII-product had significantly (p < 0.05) higher inhibiting compounds (mainly Menthone) against pathogenic gram-positive Sa compared with those in MI and MII-products.

摘要

薄荷脱水采用了遮荫（MI）、日晒（MII）和新设计的太阳能（MIII）干燥三种方法。MI、MII 和 MIII的空气速度 ( u ) 和温度 ( Td ) 分别为 0.5、0.5 和 1.5 _m /s 以及 32、36 和 48 °C。MIII的能源利用效率、T _d / u比和干燥速率分别达到85%、48°Csm ^-1和12.5 g _H2O /min，均高于MI和MII。薄荷干对金黄色葡萄球菌6-log菌落形成单位/ml的抑制能力（Sa) 也进行了评估。MIII产品的叶绿素和精油提取率分别比MII产品高30%和60%，总酚含量和抗氧化活性比MI产品高25%和26%。与 MI 和 MII 产品相比，MIII 产品的精油 对致病性革兰氏阳性Sa的抑制化合物（主要是薄荷酮）显着（ p < 0.05）更高。