荔枝果皮褐化與多酚氧化酵素及過氧化酵素之關係

Abstract

The objectives of this experiment were to investigate the relationship between pericarp browning, polyphenol oxidase and peroxidase activity of litchi fruits, and hope to distinguish the importance role of two types of enzymes to litchi pericarp browning. Results showed that water loss of fruit mainly occurred. During pericarp browning of ‘Hei Yeh'litchi fruits, peroxidase activity of the peel was higher than the polyphenol oxidase activity, and showed a tendency to increase during storage. However, variations of polyphenol oxidase activity were not coincidental. Furthermore, when fruits at low humidity induced pericarp browning, the obvious increase phase of peroxidase activity was earlier than polyphenol oxidase. Therefore, it seemed that changes in the peroxidase activity were more significant than the polyphenol oxidase activity in respect of litchi pericarp browning.本試驗的目的在研究荔枝於採收後的貯藏期間，果實乾燥失水時，果皮內的多酚氧化酵素及過氧化酵素的活性變化情形，期能釐清此兩種酵素與荔枝果皮褐化上之相關性。結果顯示，隨著果實失水而褐化期間，果皮內的過氧化酵素活性均上多酚氧化酵素活性高，並且隨著貯藏時間其活性呈增加的趨勢而多酚氧化酵素活性則無一致的變化，此外，當貯藏於低濕下的果實發生明顯的果皮褐化時，其過氧化酵素活性顯著上升時期也比多酚氧化酵素早。因此，過氧化酵素活性表現比多酚氧化酵素活性，對荔枝果皮褐化影響較大