Changes in invertase activity of melon fruit in relation to sugar content

This paper reports the changes in the sugar of melons (Cucumis melo L.) in relation to invertase activity and also examines the properties of this enzyme in the three cultivars, 'Honey Dew', 'IW-57' and 'Ginsen'. The maximum invertase activity in the soluble fraction was observed at 20 days after anthesis for 'Honey Dew' and 'Ginsen', and at 40 days for 'IW-57'. The highest sucrose content of 'Honey Dew' and 'IW-37' was seen at 45 days after anthesis, whereas that of 'Ginsen' was at 40 days. The increase in sucrose contentcoincided with the period of the lowest invertase activity. However, the increase in invertase activity was not accompanied with the changes of reducing sugar content.