Studies of freeze-thaw treatment on the mechanical properties of konjac glucomannan/κ-carrageenan-based Pickering emulsion gel

This study investigates the effects and underlying mechanisms of freeze-thawing on the mechanical properties of Pickering emulsion gels composed of konjac glucomannan/κ-carrageenan (KGM/CRG) induced by K 2 CO 3 . The results showed that as the number of freeze-thaw cycles increased, syneresis and water loss during the squeezing of the gels significantly rose, while their shear strength gradually increased. After two freeze-thaw cycles, the gel exhibited maximum hardness. Microstructural analysis revealed that ice crystals disrupted the original gel network, leading to the aggregation of oil droplets and the dissipation of water. During freezing, the crystallization of water enhanced interactions among polysaccharide molecules, resulting in a more robust and denser KGM-CRG network. X-ray diffraction analysis confirmed an increase in the crystallinity of the gel following freeze-thaw cycle treatment. Furthermore, compared to fresh samples, the freeze-thawed emulsion gels displayed higher storage and loss modulus. These findings suggest that Pickering emulsion gels show increased mechanical properties after treatment. Additionally, this study illustrated the potential mechanisms by which freeze-thaw treatment modifies the microstructure of Pickering emulsion gels and influences their gel properties, providing a theoretical foundation for the design of emulsion-gel foods through freeze-thaw cycle treatment.