Pressurized hot water crosslinking of gelatin-alginate for the enhancement of spent coffee oil emulsion stability

•Subcritical water was used to prepare gelatin/alginate (G/A) hydrogels.•Structural and morphological characterization of hydrogels was performed.•Different temperatures revealed G/A crosslinking and degradation patterns.•G/A hydrogels were used to stabilize the spent coffee oil emulsions.•Emulsions stability linked G/A functionality with their structural integrity.