Resistant Starch

Abstract

Resistant starch (RS) is starch that is not converted into glucose during its passage through the small intestine. There are five types of RS and four of those are used as food ingredients (RS2, RS3, RS4, and RS5). RS2 is native, uncooked/ungelatinized starch granule and is resistant to α-amylase attack because of the granule organized, semi-crystalline structures. RS3 is retrograded starch (primarily amylose) that is resistant to α-amylase attack due to its crystalline nature. Several processes are employed to enhance its yields, increasing the amounts of linear starch chains of crystallizable size. RS4 is starch that has been chemically modified to an extent that prevents binding of starch polysaccharide molecules in the active site of α-amylase (substitution) or that strongly inhibits granule swelling and solubilization (cross-linking), or whose molecular structures have been altered by other chemical reagents or enzymes. RS5 products are partially crystalline amylose-lipid complexes. RS products have been successfully incorporated into bakery and beverage products. The health benefits achieved when a RS product replaces some of the flour or starch in a food formulation are related to a decreased glycemic response and an increased production of butyric acid in the colon, which maintains or improves colon health.