Beans stored for long periods at high temperature and humidity become hardened and resistant to cook. This happens due to the development of the hard-to-cook defect. The objective of this work was evaluate some physical and chemical properties of the aged dry black common beans (Phaseolus vulgaris L.), Iapar 44 cultivar. The aging of beans was accelerated at 41ºC and 75% RH, for 30 e 60 days; and new beans, kept at 5ºC and 60% RH was used as the control. The cooking time, determined by a Mattson-type cooker; the chemical composition and the pH of the grains; the water solubility and protein eletrophorectic profile were evaluated. The results were submitted to analyses of variance and mean comparison Tukey test (p<0.05). It was observed that the two storage periods, caused: increased time of cooking; decreased percentage of humidity, increased percentage of ash and maintained the percentages of protein, lipids and carbohydrates; decreased pH and decreased solubility and changed the protein eletrophorectic profile. These results are in accordance with the literature, which demonstrated that during aging of beans at high temperature and humidity there is acid formation, resulting in decreasing of solubility and thermal stability of protein.
eletroforetic profile; hard-beans; Phaseolus vulgaris; pH; proteins; solubility
