HPLC determination of sugars in varieties of chestnut fruits from Galicia (Spain)

The major components in chestnut (Castanea sativa Mill) are carbohydrates, mainly starch, followed by sucrose. This disaccharide is one of the most important parameters for the assessment of the commercial quality of these fruits. In this study we assessed glucose, fructose and sucrose contents in different varieties of chestnut (C. sativa Mill) using high-performance liquid chromatography (HPLC), by means of a universal light scattering detector. We dried the samples using freeze-drying and then we extracted the sugars by means of an ultrasonic bath, using a hydroalcoholic solution at 80% (v/v). We estimated that the accuracy of this method had a variance of 1.42% for a sucrose content of approximately 22%. We obtained a recovery rate of sucrose of 86%. We obtained values of sucrose ranging between 6.5% and 19.5%, whilst glucose and fructose contents were very low, and ranged between 0.00 and 0.27 for glucose and 0.04 and 0.31 for fructose, with a relation near one, which seems to indicate that they are the result of sucrose hydrolysis.