Resistant starch in common starchy foods as an alternative to increase dietary fibre intake

Nutritional classification of dietary saccharides considers as indigestible saccharides those that are incompletely or not absorbed in small intestine. Resistant starch (RS) as a part of dietary fibre (DF) is a type of indigestible saccharide. The addition of natural RS from some fruits, legumes or cereals to commonly eaten starchy foods is a good alternative to increase the DF intake representing, at the same time, new uses for uncommon sources of DF. This review deals with RS contents of commonly consumed starchy foods and shows their potential health-beneficial properties in situations where glucose tolerance is impaired, such as diabetes mellitus or obesity. For example, the current daily intake (193 g per day, fresh basis) of maize-tortilla in Mexico represents 1.8g RS. However, tortilla prepared by blending maize with flaxseed (20%) exhibits a notably higher RS content (8.5 g per day). These staple foods added with natural RS sources show low or moderate in vitro starch hydrolysis rates and predicted glycaemic indices. Current nutritional and technological trends include the development of new formulas for traditionally consumed products. The combination of starchy foods with high RS content and/or the addition of natural RS sources to common food products could help to reach this objective.