Abstract
For the purpose of cultivating high-quality mitsuba (Japanese honewort, Cryptotaenia japonica Hassk, cv. 'Osaka-Shiroguki Mitsuba') without reducing its yield, the differences in physiological and chemical properties with varied durations of concentrated solution culture in mitsuba were determined in this study. The following four test lots were established for the solution culture of mitsuba : Control lot (cont.) -cultivated with 0.5 unit culture solution for 30days from planting to harvest, 10-day lot (10d) -cultivated with 0.5 unit for 20 days from planting and with 1.5 unit for the remaining 10 days, 20-day lot (20d) -cultivated with 0.5 unit for 10 days from planting and with 1.5 unit for the remaining 20 days, and 30-day lot (30d) -cultivated with 1.5 unit for the duration of cultivation. The yield was highest in cont., and the longer duration of 1.5 unit solution culture resulted in the shorter plant length during cultivation and the lower yield. The shorter duration of 1.5 unit solution culture caused the lighter green leaf colors and higher lightness. In the sensory evaluation, the flavor of cont. lot was weaker than that of 30d. But there were no significant differences in flavor among 10d, 20d and 30d. Freshly harvested mitsuba was divided into leaf blades and stalks to determine the contents of chemical components (chlorophyll, phenols, free amino acid) for each portion of the plant. The contents of these components were higher in the leaf blades than in the stalks. Also, the contents of these components were lowest in cont. for both portions and increased in proportion to the duration of 1.5 unit solution culture. The respiration rate was higher with the leaf blades than with the stalks and lowest in cont. for both portions, and rose in proportion to the duration of 1.5 unit solution culture.
