Sustainable Synthesis of Food-Grade Emulsifiers from Waste Cooking Oil via Enzymatic Glycerolysis in a Green Solvent System

The increasing demand for sustainable food-grade emulsifiers has stimulated interest in enzymatic processes utilizing renewable feedstocks. However, the use of waste cooking oil (WCO) for the enzymatic production of monoacylglycerols (MAG) suitable for food applications has been poorly explored. In this study, WCO was successfully upcycled into MAG through lipase-catalyzed glycerolysis using an immobilized enzyme in tert-amyl alcohol as a green solvent. Process parameters, including enzyme loading, glycerol-to-WCO molar ratio, temperature, and solvent concentration, were optimized. Under optimized conditions, a MAG yield of 67% was achieved. The resulting MAG exhibited emulsifying properties comparable to those of commercial surfactants in oil-in-water systems. Overall, this work demonstrates a sustainable strategy for the upcycling of WCO into high-value emulsifiers, contributing to circular economy principles in food ingredient production.