Development of high internal phase emulsion utilizing guar gum and soy lecithin as co-emulsifiers and its impact on the quality of chiffon cake as a fat substitute

Polysaccharides are known for their stability and resistance to environmental changes, but their limited emulsifying capacity has restricted their application in high internal phase emulsions (HIPEs). This study prepared HIPEs using guar gum (GG) in aqueous phase and soybean lecithin (LEC) respectively in aqueous phase and oil phase as co-emulsifiers. Subsequently, the interfacial, structural and rheological properties related to emulsifying ability were characterized to explore their interactions. Finally, the impact of HIPEs as margarine substitutes on the baking characteristics and storage properties of cakes was investigated. Results indicated that when LEC concentrations were between 3.5 % and 7.5 %, the synergistic interaction of LEC dissolved in the oil phase with GG in the aqueous phase led to the superior interfacial activity. This significantly reduced the droplet size of HIPEs, effectively enhanced the gel network strength and apparent viscosity, and demonstrated good stability under centrifugation and heat treatment conditions. In cake preparation, replacing 35g margarine (15 %) with 23g HIPEs (10 %) notably improved the baking characteristics. Color, texture, and sensory evaluations showed comparable scores between 10 % HIPEs and 15 % margarine cakes. Interestingly, the results of the aging kinetics equation demonstrated that the incorporation of HIPEs effectively slowed down the starch retrogradation rate of chiffon cakes during storage. This study provides a new idea for the preparation of HIPEs using natural emulsifiers and polysaccharides as co-emulsifiers, as well as for the application of polysaccharide-based HIPEs in cakes.