Enzymatic Production of Highly Unsaturated Monoacyglycerols and Diacylglycerols and Their Emulsifying Effects on the Storage Stability of a Palm Oil Based Shortening System

Abstract

MDs [monoacylglycerols (MAGs) and diacylglycerols (DAGs) mixture] are widely-used emulsifiers in specialty fats industrial production. An enzymatic production of highly unsaturated MDs (HUSMDs) and its effects on the storage stability of a palm oil-based shortening system are reported. Oleic acid and corn oil were used to produce HUSMDs in a bubble column reactor (BCR) system in the presence of Novozyme 435. Under the optimized reaction conditions, the content of HUSMDs in the products was above 82 wt% with 46.67 wt% of MAGs and 35.56 wt% DAGs, respectively. Moreover, in the subsequent evaluation of MDs' effects on the storage stabilities of a palm oil-based shortening system (IEPO), HUSMDs proved to be a potent emulsifier with decent aeration properties and a possible alternative to saturated MAGs and DAGs (SMDs) made from fully hydrogenated high erucic acid colza oil. Compared with SMDs, HUSMDs decreased the crystallization rate significantly. The microstructure of them shows improved stability of beta' crystals, and no obvious aggregation of crystals was recorded in IEPO with HUSMDs, which also demonstrated the most stable hardness.