Mechanism of konjac glucomannan to improve the freeze-thaw quality of traditional oat-based food Youmian Yuyu

The effects of konjac glucomannan (KGM) on the water status, starch recrystallization, and protein conformation of Youmian Yuyu (ONF) during freeze-thaw cycles (FTCs) were examined. The results showed that KGM markedly inhibited the rise in freezable water content, limited water migration throughout the FTCs, and reduced structural damage induced by ice crystals. Microscopic observations indicated that ONF with added KGM exhibited a more uniform and intact starch-protein network. The X-ray diffraction analysis revealed that KGM reduced the relative crystallinity and inhibited starch recrystallization. The protein structural analysis indicated that KGM addition promoted transition of the protein secondary structures from disordered to ordered conformations, thus effectively inhibiting disulfide bond disruption induced by FTCs. In summary, KGM significantly enhanced the freeze-thaw stability of oat noodles by regulating water distribution, inhibiting starch recrystallization, and stabilizing protein structures. These findings provide a theoretical basis for optimizing the industrial quality of traditional naked oat products. • Konjac glucomannan (KGM) effectively inhibited the formation of freezable water. • KGM effectively inhibited the water migration during freeze-thaw cycles (FTC). • KGM delayed starch retrogradation induced by FTC. • KGM reduced disulfide bond breakage induced by ice recrystallization. • KGM enhanced the storage quality of frozen naked oat flour products.