STARCH BIOAVAILABILITY in TWO COMMERCIAL BEAN VARIETIES (Phaseolus vulgaris L.) and in INDUSTRIALIZED BEANS

In México, beans represent up to 15% of the normal diet, but there are not studies reported on starch bioavailability, although is the major component of beans. Chemical composition and starch digestibility of processed commercial bean products and seeds from two commercial bean varieties, were studied. Commercial flours did not show differences in protein and ash contents, canned beans did not show differences (p>0.05) in protein content, but the two varieties of beans (Phaseolus vulgaris L.) cooked in the laboratory (negro and flor de mayo) were different. Canned beans and commercial beans seeds were different in ash. Lipid content in the commercial flours was different due to formulation used in their preparation, although the canned bean samples had similar lipid values. Canned samples had the highest available starch (AS) values and the commercial bean seeds the lowest one. Canned beans and bean cooked in the laboratory had the lowest resistant starch (RS) values, and the flours obtained from these samples had the highest. Retrograded resistant starch (RS type III) showed the same pattern as RS (type II + type III), but with lower absolute values. The in vitro a-amylolysis rate for canned beans, commercial flours and bean cooked were lower than for dried samples. Thus, the additional drying period increased the hydrolysis rate of the samples.