Beans are a rich source of polyfenols that help us to stay healthy. At least, if you know, how to increase their content, as it changes during storage and preparation. So, what are the best ways of preparing beans to benefit the most from their healthiest polyfenols?
First of all, beans need to be stored properly. A humidity of more than 65% and a storage temperature above 25°C decreases the nutritional value of beans.
Fermentation and germination (or sprouting) both improve the nutritional value of beans, including a.o. increased content of polyfenols and protein digestibility. Sprouted beans have another big advantage: they possess flavonoids, namely isoflavones and myricetin derivatives, that are not present in raw or cooked beans.
Soaking slighly reduces some polyfenol types, in particular the phenolic acids and tannins, of the beans from 95 to 81%, while increasing the other type of polyfenols (flavanones) from 7 to 13%, which decreases to 5% after cooking.
From the available thermal preparation of beans, extrusion (cooking fast at high temperature & under high‐pressure) and roasting after soaking are the most suitable for increasing content of polyfenols. At third place is dehydration of beans.
Cooking in water seems to be the worse option, as it leads to reduction of 68% in the specific type of polyfenols (namely, anthocyanins).
Curious? HERE is the source