Changes in starch properties during malting and their correlations with the malting quality of multiple barley cultivars

Abstract

Background and ObjectiveThere is still a lack of information about detailed dynamic changes in starch properties during malting among multiple barley varieties and correlations of starch properties with malting qualities. In this work, compositional, physicochemical, morphological, and structural properties of starches from four barley varieties at six time points across the malting process were first investigated to better understand the starch modification of barley malting. Furthermore, a total of 30 barley varieties were used to investigate the relationship between malting qualities and starch properties. The results provide a reference for breeding high‐malting quality barley based on starch properties.FindingsSignificant decreases in starch contents, paste viscosities, relative crystallinity, as well as the ratio of 1045/1022 cm−1 of starch, were exhibited, while comparatively small changes were found in the thermal parameters during malting. Amylose and amylopectin polymers were both hydrolyzed in malting. After malting, pits and holes were discovered on the surface of some starch granules. Four parameters of peak viscosity (PV), breakdown, peak time (PeT), and pasting temperature (PT) had significant correlations with diastatic power (DP), while the above four indicators together with amylose content, total starch content, onset temperature, peak temperature, and swelling power had significant correlations with malt extract (ME).ConclusionsThe trend of changes in starch properties among all four genotypes was similar. However, the variety with better malting quality showed a greater degree of measurements in some starch characters. Starch properties are mainly related to the two malting quality indicators of DP and ME.Significance and NoveltyPV, breakdown, PeT, and PT had significant correlations with malting qualities.