Water chestnut starch: extraction, chemical composition, properties, modifications, and application concerns

Abstract

The increase in non-biodegradable waste has prompted research on the development of new biodegradable compounds that can act as substitutes for the prevalent synthetic materials used for packaging. In this regard, due to the advantages of starch including its biodegradable, abundant, cost effective, and non-texture nature, it has attracted attention in the food and pharmaceutical industries. Presently, numerous studies have been reported on the search for new sources of starch. Herein, we summarize research on water chestnut as a non-conventional source of starch. Advantageously, due to low protein, ash and lipid content in water chestnut, its processing requires little effort and a large pure starch fraction can be extracted. The large amount of carbohydrates in water chestnut makes it a tremendous reservoir of starch for the food and non-food industries and it can replace other commercial sources of starchy such as wheat and potato. The starch in water chestnut can be extracted using a series of methods including centrifugation, and subsequently, its purification results in shapes ranging from elliptical and globular to prismatoid. However, the native form of starch is not stable with variations in temperature and pH, which restricts its use in specific applications. Thus, native starches are commonly altered to achieve improved characteristics such as solubility, swelling, texture, and thermal tolerance. Starch from water chestnut is known to show potential as a pharmaceutical excipient and also a potent candidate for the prevention of type II diabetes and obesity. This review highlights the physiochemical properties, modifications and applications of water chestnut starch in the food and non-food industries.