Comparative analysis of starch multiscale structure and physicochemical properties with the yield of mung bean paste

Mung bean paste yield varies significantly among cultivars, yet the underlying mechanisms remain unclear. Analysis of 30 mung bean cultivars revealed that paste yield was significantly positively correlated with starch content (r = 0.45, p < 0.05) and negatively correlated with protein content (r = -0.58, p < 0.05), while showing no significant correlation with fat and dietary fiber content. Starches isolated from high-yield mung bean cultivars exhibited significant differences in multiscale structures and physicochemical properties compared with those from low-yield cultivars. Pearson correlation analysis revealed that the paste yield of mung beans was significantly positively correlated with amylose content (r = 0.82, p < 0.05) and amorphous structure proportion (r = 0.86, p < 0.05) of their starches, while it was significantly negatively correlated with relative crystallinity (r = -0.82, p < 0.05), double helices proportion (r = -0.89, p < 0.05), final viscosity (r = -0.97, p < 0.05), setback value (r = -0.84, p < 0.05), and gelatinization enthalpy (r = -0.85, p < 0.05). Moreover, starches from high-yield cultivars exhibited relatively uniform granules with compact and smooth surfaces and higher loss tangent values. These properties could facilitate the disruption of starch granules, massive water absorption, and extensive release of internal components during heating, thereby forming a stable but loose gel network and improving the paste yield. This study provides a theoretical basis for cultivar selection and optimization of industrial processing for mung bean paste production.