CHANGES IN DIETARY FIBER CONTENT AND ITS COMPOSITION AS AFFECTED BY PROCESSING OF BLACK BEANS (PHASEOLUS-VULGARIS, TAMAZULAPA VARIETY)

This paper presents the effect that the traditional cooking process of black beans (Phaseolus vulgaris, Tamazulapa variety) has on the quant ity and composition of soluble (SDF) and insoluble (IDF) dietary fiber of beans, as well as on its protein digestibility and protein quality . There was an increase of IDF from 18.1% in cooked beans to 22.4% in fried beans, and a decrease in SDF from 8.4% to 6.6%, respectively. St arch content decreased from 34.5% to 31.3%. No change was found in lig nin. The xylose content was higher in IDF than in SDF and decreased to some extent from cooked to fried beans. Arabinose content was similar in IDF and SDF with no change caused by processing. The fraction cont aining glucose, mannose and galactose in IDF was higher than in SDF, t he content increasing in IDF and decreasing in SDF, with processing. P rotein content in IDF was higher than in SDF, with no major change whe n processing. About 29.5% of the total protein of beans was bound in D F. Protein digestibility and protein quality decreased from cooked to fried beans and was positively related to IDF.