A simple colorimetric method for the determination of sugars in fruit and vegetables



A rapid, manual colorimetric method for determining glucose, fructose and sucrose in fruit and vegetables is described. The method is based on the determination of reducing sugars before and after invertase digestion using p-hydroxybenzoic acid hydrazide (PAHBAH). Total fructose (fructose plus fructose in sucrose) is determined using 2-thiobarbituric acid and the component sugars calculated. Addition of sugars to fruit extracts gave good recoveries (97.4–101.8%) for glucose, fructose and sucrose.