Effect of Konjac Glucomannan with Different Molecular Weights on the Structural Characteristics and Gel Properties of Antarctic Krill Myofibrillar Protein during Frozen Storage

This study explored the effect and underlying mechanisms of different molecular weights of konjac glucomannan (KGM) on the structure and gel properties of Antarctic krill myofibrillar proteins (MP) during various durations of frozen storage. As the duration of frozen storage increased from 0 to 180 days, the total SH content and tensile properties of the MP complex gel exhibited a decline trend. However, the addition of KGM, HMW-KGM (high molecular weight, KGM), MMW-KGM (medium molecular weight, KGM), and LMW-KGM (low molecular weight, KGM) significantly mitigated the variations in the structural and rheological properties of the MP and KGM-MP complex gel. Furthermore, the total sulfhydryl (SH) content, Ca²⁺-ATPase activity, ζ-potential, and α-helix content of the secondary structure of MP significantly enhanced, with the maximum values observed upon the addition of MMW-KGM. Observations of microstructure and rheological properties also indicated that the incorporation of MMW-KGM stabilized the microstructure of the MP complex gel and maintained the highest storage modulus (<i>G</i>') value. The utilization of konjac oligosaccharide showed prospective industrial applications in the quality improvement of Antarctic krill.