Preparation of two-step cold-set low oleogel-microgels phase bigels and its application in tender fish balls: Pork fat substitute and cryoprotectant

The high moisture content and low oil levels in the bigels easily led to oil-water separation. The stability of bigels prepared from 30 % beeswax sunflower oleogel and 70 % gelatin hydrogel was evaluated using a two-step cold-set synergistic continuous dispersion method. Both the oleogel and hydrogel had formed a gel system, respectively, at low temperature prior to the preparation of bigels. The dynamic process of cold set and further dispersion of initial bigels was named two-step cold-set synergistic continuous dispersion. Results indicated that this dynamic process significantly reduced the size of oleogel microgel particles, thereby increasing the adsorption area of interfacial proteins. Oleogel microgel particles uniformly filled the hydrogel network, forming a stable oleogel/hydrogel structure. Moreover, an increase in hydrophobic interactions, resulting from the cold set of the initial bigels to continuous dispersion, contributed significantly to interfacial stability. Furthermore, modulated bigels replacing 50 % pork fat significantly increased the water content (from 69 % to 75 %), freshness, and flavor richness of fish balls compared with the full-fat group. The bigels reduced the ice crystal size in low-fat tender fish balls during freeze-thaw cycles. In conclusion, the dynamic processes greatly improved the structural stability of low oleogel-based bigels without the use of emulsifiers. Modulated bigels show promising potential as a pork fat substitute and cryoprotectant for tender fish balls.