CHANGES IN THE CARBOHYDRATE-COMPOSITION OF LEGUMES AFTER SOAKING AND COOKING

Using a high-performance liquid chromatography (HPLC) method, research ers analyzed the sugar composition of chick-peas, kidney beans, and le ntils at various points in the preparation and cooking process: after soaking, after ''normal'' cooking (ie, boiling), after pressure-cookin g, and after cooked legumes had been held at 35-degrees-C for 5 hours. There was a considerable decrease in the amount of monosaccharides, d isaccharides, and raffinose oligosaccharides in chick-peas and kidney beans after soaking and cooking. This change in carbohydrate compositi on was less pronounced when the cooking water was not drained before a nalysis, which was the method used when analyzing the lentils. Method of cooking (either boiling or pressure-cooking) did not have different effects on the sugar composition of chick-peas and lentils, but loss of oligosaccharides was slightly higher when kidney beans were boiled than when they were pressure-cooked. Loss of alpha-galactosides occurr ed in chick-peas and kidney beans that had been boiled and then held a t 35-degrees-C for 5 hours. The HPLC analysis showed that manninotrios e was not one of the oligosaccharides present in these legumes.