Resistant starch is not broken down in small intestine. However it is not fully digested but some part turned into short chain fatty acid by intestinal bacteria in large intestine and produce short chain fatty acid along with some gases. These short chain fatty acid gives various health benefits as it improve digestive system,metabolic health and boost immune health.
Starch is the major carbohydrate in our daily routine diet it is found in grains, potatoes and various foods are good source of starch. Starch is a long chain of glucose molecule (polysaccharide).
All starch are made up of 2 types of polysaccharides
Amylopectin, which is highly branched chain structure having more surface area for digestion so easily digested and give quick rise in blood glucose level. Where amylose has straight chain structure gives less area for digestion and less likely raise blood glucose level.Food high in amylose slowly digested therefore known as resistant starch.
Types of resistant starch
There are 4 type of resistant starches
Type 1- physically inaccessible- not get digested because they are bound in fibrous cell wall and protein matrices. Found in grains, seed and legumes.
Type2- resist in digestion due to its crystalline structure found in potato (raw) banana (unripe)
Type 3- retrograde starch it forms when starchy food cooked and cooled like rice, potato pasta
Type 4 -man made or chemically modified found in bread and cake.