Day-to-Day Fluctuations of the Sugar Contents in Cucumber Fruits and the Application of Disposable Blood Glucose Sensors for Quality Estimation of the Fruits

Abstract

Day-to-day fluctuations in the sugar contents of cucumber fruits harvested at the same greenhouse were investigated. The fruits contained glucose and fructose in almost equal quantities. The contents of the glucose (and fructose) in the fruits fluctuated between 0.8% and 1.4%, dependent on the date of harvest. A relationship was shown between glucose contents in the fruit and the weather on the day before harvest; shorter duration of the sunshine or shading treatment decreased the glucose contents of fruit harvested the next day. Because the sugar contents of cucumber fruits varied day-to-day, it is useful to measure the sugars in the fruits simply and rapidly in order to obtain cucumbers of high quality. A disposable blood glucose sensor (biosensor) was used to measure a glucose in the fruits. The results obtained by the biosensor showed high correlation with the data on glucose obtained by capillary electrophoresis. Because the sample preparations were very simple and it took less than 10 min to obtain the results, this method using the biosensor appears to be quite effective for the rapid measurement of the glucose contents in cucumber fruits.