Physical Characteristics of the Essential Oil Extracted from Released and Improved Spearmint Varieties, Peppermint and Japanese Mint
The mint species namely spearmint, peppermint and Japanese mint which belong to the genus mentha, the family Lamiaceaeare the most aromatic and medicinal plants those Wondo genet Agricultural research center is working on their different research activities and releasing different varieties. The essential oils were extracted using the hydrodistillation method. This study investigated the analysis of physical characteristics of spearmint varieties, peppermint and Japanese mint essential oils. The analyzed physical properties were Essential Oil Content (EOC), specific gravity (relative density) and refractive index. The three released spearmint varieties namely Liyu, WGSM03 and WGSPM Fran (java) have equal essential oil content and relative density with value 0.8% and 0.9210 respectively. WGSPM fran (java) has highest refractive index with the value 1.489 ± 0.002. The value of the refractive index for the other two varieties was 1.487 ± 0.002 and 1.485 ± 0.002 for WGSM03 and Liyu respectively. The oil content, specific gravity and refractive index of peppermint were 1.3%, 0.9215 and 1.462 respectively whereas Japanese mint contains 0.7% essential oil content, 0.9210 specific gravity (relative density) and 1.460 refractive indexes.