The structural characteristics of starches and their functional properties

Abstract

Starch is composed of amylose and amylopectin and deposited as granules of different sizes and shapes with semi-crystalline and amorphous concentric layers that show the 'maltese cross'. Starches from different sources show variable chemical composition as well as the structure of their components that are involved in thermal properties. Amylose, lipids, phosphorylated residues and long lateral chain amylopectin interact among them avoiding water uptake. In contrast, high amylopectin contents, especially with short lateral chains, allow hydration via hydrogen bonds to form gels with the tendency to retrogradation. Smaller starch granules have a larger superficial area, surface pores, and channels that enhance water uptake. High hydration increases the swelling, viscosity, and gelatinization ability of starch granules. The knowledge of those properties allows the selection of the most appropriate starch for a specific end use. This review discusses the relationship between the physicochemical composition of the starch and their rheological properties. Características Estructurales de Almidones y sus Propiedades Funcionales RESUMEN El almidón está compuesto de amilosa y amilopectina y es depositado en forma de gránulos de diferentes tamaños y formas con capas concéntricas que pueden ser semi-cristalinas o amorfas donde se observa la llamada cruz de Malta. Los almidones de diferentes fuentes varían en composición química, así como también en la estructura de sus componentes que están involucrados en las propiedades térmicas. La interacción entre amilosa, lípidos, residuos fosforilados y cadenas largas de amilopectina disminuye la absorción de agua. Lo opuesto sucede cuando se tiene un alto contenido de amilopectina con cadenas laterales cortas, gránulos de almidón pequeños, así como la existencia de poros superficiales y canales. Una alta hidratación de los gránulos de almidón aumenta el hinchamiento, viscosidad, habilidad de gelatinización y la retrogradación del gel después de largos tiempos de almacenamiento. El conocimiento de estas propiedades permite la selección de la fuente de almidón apropiada para un uso final específico.

Wx Gene in Hordeum chilense: Chromosomal Location and Characterisation of the Allelic Variation in the Two Main Ecotypes of the Species

“…The most studied, in this context, has been the ADP glucose starch glycosyl transferase (GBSSI or the waxy proteins) solely responsible for amylose synthesis. This starch synthase has been studied in several cereal species, mainly those in which the starch properties are important for their use in the agri-food industry or in bio-ethanol production [46].…”

The Physicochemical Characterization of Unconventional Starches and Flours Used in Asia

“…The higher protein and fat content in red rice flour and water chestnut starch restricted their swelling capacity [24]. The double helices structure of amylose is more stable and heat is needed to break the hydrogen bonds so that the amylose can bond with water molecules which contributes to the swelling of the starch granule [25]. Thus, the high amylose content in high amylose maize starch restricted its swelling capacity.…”

Effects of starch type and concentration on the physicochemical properties of bilayer‐stabilized oil‐in‐water emulsion gels enriched with β‐1,3/1,6‐D‐glucans

“…Moreover, amylose leached out during gelatinization can form a three-dimensional network, stabilized by hydrogen bonds, whereas the ability of swollen starch granules composed mainly of amylopectin is generally very weak. 20,21 Changes in η a allow modification of food texture, e.g. a reduction provides advantages during high-shear processing operations, whereas an increase results in the desired mouthfeel during consumption.…”