Starch, composed of amylose (AMY) and amylopectin (AP), is a common constituent of many agricultural grain crops and the main source of energy for both humans and domesticated animals. There are several physiochemical factors that determine the suitability of starch for a specific end use, which mainly entails the ratios of the AMY and AP, but also the granular and molecular structure thereof. This, in turn, determines its functional properties, i.e. swelling, gelatinisation, pasting and retrogradation. Different instruments, such as the Amylograph®, Falling Number® System, Ottawa Starch Viscometer and the Consistometer, in addition to the more recently developed Rapid Visco Analyser (RVA) are used to study the functional properties of starch. Due to its reliability, repeatability and versatility, the RVA is increasingly used to determine the physiochemical and, in particular, the pasting properties of cereal starches. This review gives an update on the current knowledge of starch-related physiochemical and functional properties of a selection of cereal (i.e. wheat, barley, rice and maize) starches, and the RVA as a measuring instrument thereof, including critical analysis and discussion.

SummaryStarch is a major determinant of grain quality in cereals but the variation in starch structure has yet to be fully explored in its relation to processing impacts. This study examined the starch properties of South African grown malting barley varieties. Starch amounts, amylose content, covalently bound phosphate, starch granule size, starch molecular structure and pasting properties were examined. There was no difference in amylose content but there was variation in the amylose chain length distribution, despite all barleys showing similar granule parameters. The longer amylose chain length resulted in increased pasting temperature. There was no difference in phosphate content for these samples. Starch properties for the brewing industry are important in the context of the production of fermentable sugars. The variation in starch structure was not observed when measuring content and could impact on fermentation efficiency through variation in fermentable sugars hydrolysed from the starch.