Developments in the isolation, composition, and physicochemical properties of legume starches

The purpose of this write-up is to discuss the recent developments in the study of the physicochemical and functional properties of legume starches. Legumes are abundantly rich in proteins, polysaccharides, vitamins, and minerals. Starch is the most important polysaccharide in the human diet. The amylose, lipid, ash, and nitrogen content of legume starches vary in the range of 18-52%, 0.1-0.9, 0.0-0.7%, and 0.0-0.3%, respectively. The legume starches are characteristically rich in amylose, display limited swelling power, poor dispersibility in water, and vulnerable to retrogradation. The properties of legume starches reveal that they possess strong bonding chains between its molecules. Due to these strong bonds, legume starches have high gelatinization transition temperatures and enthalpies. Furthermore, the pasting properties are in accordance with this concept. Legume starches differ in granule morphology, gelatinization transition temperatures, and amylose content. There is need for modification of legume starches due to poor functionality such as easy vulnerability to retrogradation and poor processing properties when subjected to extreme of conditions. These shortcomings of legume starches are usually mitigated by annealing, heat-moisture treatment, cross-linking, acid-thinning, oxidation, and acetylation. This review highlighted developments in the isolation, composition, morphology, physicochemical properties, and some aspect of physical and chemical modification of legume starches.