Effect of domestic processes and water hardness on soluble sugars content of chickpeas (Cicer arietinum L.)

An HPLC method for sugar analysis on legumes has been applied to three different Spanish cultivars of chickpeas, to evaluate changes on the soluble sugar fraction (with special attention to α-galactosides) during domestic processing (soaking and cooking) using two types of water with different hardness. Processing liquids were also analysed. Ciceritol, was the main sugar in all the samples. Raffinose and stachyose concentrations were from 1.312 to 1.947 g/100 g in raw samples. Soaking liquids extracted less than 4.86% of the α-galactosides of raw seeds with no considerable amounts of flatogenic sugars. Decreases of raffinose + stachyose after processing were between 24.7 and 42.6%. Cooking liquid contents of α-galactosides ranged from 0.282 to 0.565 g/100 ml, (0.119–0.302 g/100 ml of flatogenic sugars). Statistical tests (ANOVA) showed that water hardness has no significant effect (p⩽0.05) on flatogenic sugar contents of final processed chickpeas.