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A spectrofluorimetric method and a chromatographic method [high-performance liquid chromatography -ultraviolet (HPLC-UV) detection] were compared for vitamin C analysis of green beans. For HPLC-UV, the determination was performed before [ascorbic acid (AA)] and after reduction with dithiothreitol [AA c dehydroascorbic acid (DHAA)]; for spectrofluorimetry, DHAA was determined after oxidation with activated charcoal. The fluorimetric determination of DHAA before oxidation was also carried out, and showed good precision but poor accuracy (very high recovery percentages). HPLC-UV showed better linearity and sensitivity, while spectrofluorimetry was more precise. Both methods were suitable for green bean samples, and the choice of which one to use depends on the particular interest of the analysis: spectrofluorimetry may be preferable when the total content of vitamin C is required, but not for individual analysis of each form. HPLC-UV is more suitable when the interest of the analysis is the ascorbic acid form as a deterioration index of vegetable products.

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A high-performance liquid chromatography (HPLC) method for soluble sugars analysis, using an [[(aminopropyl)methyl]silyl]-bonded amorphous silica column, was applied to several dry legumes:  chickpeas, lentils, white beans, pinto beans, and peas. Monosaccharide (ribose, fructose, glucose, and galactose), disaccharide (sucrose, maltose, and melibiose), and oligosaccharide (raffinose, ciceritol, and stachyose) composition of these samples was analyzed, with special interest on α-galactosides, because of their physiological role in inducing flatulent phenomena in humans after ingestion of legumes. Ciceritol (an inositol digalactoside) was the main sugar in chickpea samples and it was present also in lentils. In all the samples stachyose was found at higher levels than raffinose, and the content of these two flatulence-inducing sugars is higher in beans and lentils and lower in peas and chickpeas. However, great variability has been found in the sugar content of the different samples analyzed, probably due to genetic and environmental factors. The proposed method showed good results for the analysis of 10 simple and complex sugars in legumes, in a final time of about 40 min and in the same chromatographic run. Keywords: Soluble sugars; oligosaccharides; α-galactosides; legumes; HPLC