Chemical Composition, Starch Bioavailability and Indigestible fraction of Common Beans (Phaseolus Vulgaris L.)

In Mexico, consumption of beans represents 15% of the normal diet of the population in rural zones. Four common bean varieties cultivated in Mexico were studied regarding their chemical composition, starch digestibility and indigestible fraction. The protein level in the samples Huasteco, Tacana and TLP 19 was not different (α = 0.05), but Veracruz cultivar had the highest protein and ash content, and the lowest lipid level. Differences in chemical composition were determined in the cultivars studied. Total starch (TS) ranged between 33.6 and 36.7%, and the cultivars Tacana, TIP 19 and Veracruz were not different in starch content (α = 0.05). The available starch (AS) determined represented between 74 and 87% of TS, due to the resistant starch content and perhaps some complex formed between starch and protein or starch and polyphenols, by the high level of the indigestible fraction determined in the beans. The in vitro α-amylolysis rate was similar for the different varieties, except for Veracruz cultivar which presented a slightly lower hydrolysis rate.