ABSTRACT
Resistant starch (RS) is defined as the sum of starch and of the product of starch degradation not absorbed in the small intestine of healthy individuals. Most of the RS is formed in food during normal processing and much is known about how to promote its formation. Highest yields are achieved with potato and legumes (7% and 11% of total starch, respectively) due to the special nature of their starch. The main source of starch in the diet is cereal, in which only limited amounts of RS are produced by the usual processing, namely baking and extrusion cooking (2-6% of total starch). RS is constituted mainly of retrograded amylose, which consists of an association of the linear chains. Yields as high as 45% RS have been obtained with 70% amylose which is gelatinized and cooled under controlled conditions (concentration, temperature, storage time). The yield can be increased by subsequent hydrolysis of the unretrograded starch with enzymes. RS can be easily incorporated in food without altering the texture and appearance, partly due to its white color, bland taste, and microparticulate structure. It can thus be used as fat mimetic or to increase the dietary fiber content of food.
