Evaluation of bush and vine black beans for physical, chemical and nutritional characteristics

The present study was undertaken to learn if there are physical, chemical and nutritional differences between vine and bush type of beans. Four samples of black color beans (Phaseolus vulgaris) of the vine type, and four of the bush type were collected from farmers in the same growing area. The samples were analyzed for some physical properties including, 100 seed weight, size distribution percent seed coat, water absorption, cooking time, and of solids on cooking waters. Vine type beans had larger 100-seed weights, larger sized beans, thicker seed coats, and lower of solids in the cooking water than bush type beans. Rate of water absorption was different. The chemical characterization included proximate analysis and fiber fractionation. Vine type beans had, on the average, less ether extract and protein than bush type. No differences were found in fiber fractions, although there was a higher variability in the vine types. Protein quality and protein digestibility when fed as the single protein source, were similar on the average, with more variability in the vine types. Both types, efficiently supplemented maize proteins and the protein digestibility was higher than when fed alone. In general there were no large differences, except in some physical measurements, between vine and bush type beans, with the former showing greater nutritional variability which could be useful in selection programs, if such variability is confirmed.