Slowly Digestible‐ and Non‐Digestible α‐Glucans: An Enzymatic Approach to Starch Modification and Nutritional Effects

Abstract

Escalating diabetes, obesity, cardiovascular disease, and bowel syndrome have increased consumer awareness of nutrition and energy values of starch products. Slowly digestible starch (SDS), slowly digestible maltooligosaccharides (SDM), and highly branched maltooligosaccharides, so called isomaltooligosaccharides (IMOs), generated by enzyme modification of starch, provide a new concept to meet consumer demands and solve urgent health‐associated problems. The combination of starch‐active enzymes in the glucanotransferase and glucanohydrolase families to produce slowly digestible‐ and non‐digestible α‐glucans has been widely studied, mainly focusing on the activities of branching enzyme (BE), amylomaltase (AM), and α‐transglucosidase (TGase). Products obtained from the action of these enzymes have resulted in completely novel types of maltooligosaccharides that are slowly degraded and therefore digested in the small intestine to maintain regulated blood glucose levels and suppressed glycemic‐index response. Some IMOs can even escape the small intestine and become fermented by micro‐organisms in the large intestine to produce health‐promoting short‐chain fatty acids such as butyric acid. Such slowly digested α‐glucans can regulate and trigger health‐promoting gut hormone release. Different novel production strategies of health‐promoting α‐glucans, their structures and nutritional effects are discussed here.