EFFECT OF PROCESSING ON THE COMPOSITION OF DIETARY FIBER AND STARCH IN SOME LEGUMES

The effect of processing on the total dietary fibre (TDF) insoluble (I DF) and water-soluble (SDF) Fractions as well as total (TS), available (AS) and resistant (RS) starch were studied in three legumes, viz. be ngalgram (Cicer arietinum L.), Cowpea (Vigna unguiculata) and greengra m (Vigna radiata). The processes studied were fermentation, germinatio n, pressure-cooking and roasting. The dietary fibre (DF) content and i ts components were determined using the enzymatic-gravimetric method. The TS content was determined by the enzymatic method after solubiliza tion with KOH. The DF content ranged from 23.2 to 25.6 g/100 g in the raw and 16.0 to 31.5 g/100 g in the processed legumes. All the process ing treatments significantly decreased the SDF content and increased t he IDF content of all the three legumes. The mean TS, AS and RS conten t of the raw legumes were similar, 46.9, 36.7 and 10.2 g/100 g respect ively. AS content of all the legumes was reduced by the processing tre atments, except pressure cooking. Correspondingly, higher amounts of R S were observed in the processed legumes, except pressure cooked, resu lting in an increase in the TDF content.