Reviewing nano-reduction as a tool to tailor functional and nutraceutical properties of resistant starch

One of the important sources of dietary carbohydrates present in human diet is starch. However due to its ability to cause an increase in blood sugar levels, the consumer acceptance towards starchy foods has seen a rapid decline. The consumers are mostly driven towards starchy foods with low glycemic index that has paved a way to explore new sources that could replace starch. In this context, resistant starch (RS) is a type of starch that resists digestion in the small intestine and reaches the large intestine intact. It behaves as dietary fibre in our body and is associated with various health benefits including improved digestive health, blood sugar, insulin sensitivity, weight management and intestinal health. Nanotechnological modification of biopolymers has seen a surge due to improvement in nutraceutical and techno-functional properties. This goes well with RS, where nanotechnological intervention resulted in display of unique physicochemical properties for enhancing food quality and safety. These include improved shelf life, enhanced flavour profile, as a wall material for various bioactives, increased nutritional value, and as a biocompatible packaging material. The review article highlights the types, classification, isolation, chemical composition, conventional RS and RS nanoparticles (RSN) producing techniques and applicability of nano reduction techniques on RS macromolecule. Nano-reduction involves utilizing nanotechnological techniques including ball milling, high speed jet, nanoprecipitation, nano emulsion and enzymatic treatment in order to modify the structure or properties of RS at the nanoscale level. The effect of these techniques on molecular structure and functionality of RS has also been discussed. Various characterization techniques to establish nature, structure, techno-functional properties, nutraceutical potential and toxicity of the RSN have also been discussed. RSN offers potential benefits ranging from improved food formulations to advanced biomedical and environmental solutions in coming times. The review summarizes the significance of nanotechnology in modifying the techno-functional and nutraceutical properties of RS and also gives research directions on how to exploit RS nanoparticles for development of health promoting foods.