Characteristics of Quality and Processing of Mizu-nasu (Solanum melongena L.) Eggplant Fruit Based on a Varietal Comparison

Abstract

　Eggplant is a frequently eaten vegetable in Japan. A number of cultivars adapted for particular climatic environments have been developed in various regions of Japan. The Mizu-nasu eggplant, the fruit of which is mostly used to produce salted pickles, has been cultivated in the Senshu District in Osaka over time. We compared its chemical components with those of several cultivars (Torikai, Chikuyo, Kurowashi, Senryo-2, Masumi, and Shiro-nasu) that vary in shape, appearance, and additional properties to clarify the quality characteristics of Mizu-nasu. Senryo-2, Chikuyo, and Kurowashi had higher anthocyanin contents than those of Mizu-nasu and Torikai. The peel of every cultivar contained chlorophyll; however, the content was highest in Senryo-2. The polyphenol content in the peel was highest in Kurowashi. Polyphenol oxidase (PPO) activity was highest in Shiro-nasu and lowest in Mizu-nasu. In addition, the degree of browning was highest in Shiro-nasu and lowest in Mizu-nasu. These results indicate that Mizu-nasu fruit could be suitable for processing as salted pickles due to low levels of polyphenol and PPO activity as compared to the other cultivars.