QUANTITATIVE-DETERMINATION OF CARBOHYDRATES IN ORANGE JUICE BY GAS-CHROMATOGRAPHY

A gas chromatographic method using a capillary column is described for the quantitative analysis of fructose, glucose, sucrose and myo-inosi tol in orange juice. The method is evaluated for precision and recover y using phenyl-beta-glucoside as an internal standard. The results sup port the suitability of the method. Carbohydrates (fructose, glucose, sucrose and myo-inositol) were determined in different kinds of orange juice. The determination of carbohydrate composition and ratios of th e carbohydrate constituents provide a method to assess orange juice qu ality, especially the myo-inositol content and myo-inositol/fructose r atio. These new indices, which were found to be lower in samples made from concentrates, provide information on the quality and genuineness of orange juice.