Study on physicochemical, structural, and functional properties of Zhengdan958 and Xianyu335 cornstarch from newly harvested corn under postharvest ripening conditions at ambient temperature

The importance of starch in nutrition and industry is unquestionable. This study investigated the changes in physicochemical, structural, and functional properties of cornstarch from newly harvested Zhengdan958 (Zd958) and Xianyu335 (Xy335) corn during for 0, 20, 40, and 60 d at ambient temperature. The results showed no significant changes in the proximate components and apparent structure of Zd958 and Xy335 cornstarch under postharvest ripening conditions. Compared with 0 d, the molecular weight distribution and mass fraction of Zd958 and Xy335 cornstarch have changed significantly, the relative crystallinity (RC) has significantly increased from 26.4% to 26.5%-28.8% and 28.4%, and R1045/1022 has significantly increased from 0.828 to 0.826 to 0.843 and 0.883, respectively. The changes in structure indicated that the synthesis and rearrangement of cornstarch molecules formed highly ordered crystalline structures, and the ordered structures of long-range and short-range molecules increased. Moreover, the changes in structure affected the pasting characteristics and texture profiles of cornstarch, therefore, affecting the final food quality.