Quality Assessment of "Norabouna" (Brassica napus L.) Grown in Different Months in Different Regions of Kanto

Abstract

　"Norabouna" is a leafy vegetable belonging to the Brassicaceae family and is a traditional cultivar in the western part of the Kanto region. However, the morphology of "Norabouna" in various local markets is not the same because local producers have their own seeds for production and they use different cultivation practices. Therefore, we evaluated the quality of "Norabouna" produced in different regions of Kanto by analyzing the morphology, composition, and toughness of flower stalks grown in different months (March, April, and May) by various producers. The analysis showed that the morphology of flower stalks differed according to the month of cultivation, thereby altering the condition of the packaged produce. This was one of the reasons for variation in the vegetable morphology between areas and producers, because they grew the plants in different months. In addition, the chemical composition and toughness of flower stalks varied between the growing months, areas of production, and the cultivation practice used by the producer. Moreover, compared with other leafy vegetables, "Norabouna" flower stalks had high ascorbic acid and sugar concentrations, giving them a pleasant taste. Therefore, "Norabouna" can potentially become a more widely produced leafy vegetable crop, but to achieve this, further studies are required to standardize the cultivation methods and stabilize the variations in the genetic stock.