GERMPLASM CHARACTERIZATION OF ITALIAN LANDRACES (PHASEOLUS VULGARIS L.) BY FLAVONOID AND CARBOYDRATE CONTENT

Flavonoids and sugars composition of legumes are very important for a chemotassonomical point of view and for nutritional purposes. The flavonoid composition of six landraces of common bean (Phaseolus vulgaris L.), collected in two regions of Italy (Tuscany and Basilicata), has been characterised by means of HPLC/DAD and HPLC/MS analysis . Flavonols (kaempferol, quercetin and their glycosides, acetyl and malonyl glucosides) and isoflavones (daidzein and genistein) have been separated and determined in the different seeds. The quantitative data show the presence of flavonols (amounts ranging from 3.07 to 1256.63. mg/kg of dry seeds) and of isoflavones in smaller amounts. The total antioxidant capacity evaluated by DPPH test, (expressed as EC50), has been measured in all samples and has been correlated to the polyphenolic content. The second aim of this research was to evaluate soluble sugar which may be correlated whit inducing flatulence. In all samples, mono, di, and oligosaccharides were analysed by HPLC/RI and by comparison of the profile obtained with available commercial standards; ribose, fructose, sucrose, raffinose and stachyose have been identified and quantified . The total soluble sugar content changed between 5.34 and 10.71 g/100g of dry seeds, the main sugars are sucrose and stachyose, the fructose is present in some cases. These investigations show that these landraces could be considered as an important germplasm of P. vulgaris, to conserve and to utilise in breeding program to improve nutritional quality of the common bean.