Cryoprotective role of konjac oligosaccharide on silver carp proteins during frozen storage through molecular dynamic simulation

The cryoprotective effect of konjac oligosaccharide (KOG) on the silver carp surimi proteins during frozen storage was analyzed. Meanwhile, molecular dynamic simulation (MD) was carried out to examine the insight interaction of KOG with myosin. The Ca2+-ATPase and gel strength decreased in all samples, despite the treatment with a sucrose (4%) + sorbitol (4%) mixture as PC and KOG (1 and 3%). The samples added with no cryoprotectants (C) showed a remarkable decline in Ca2+-ATPase activity and gel strength. The decline in these properties could be due to oxidative changes in myosin, ice crystallization, and protein denaturation. Most interestingly, KOG (3%) incorporated samples that presented significant constancy in Ca2+-ATPase and gel strength properties, this stability was further proved with a MD computational study. Our findings of homology and MD analysis affirmed that KOG could substitute water molecules and form hydrogen bonds with amino acid residues, thereby leading to protein stability. Overall, the KOG water substitution action played an efficient cryoprotective effect on frozen silver carp protein. Furthermore, this application could extend the role of KOG at the industrial level as an effective cryoprotectant.