High internal phase emulsions (HIPE) using pea protein and different polysaccharides as stabilizers

Abstract

Liquid oil structuring by emulsification has the potential to develop products with low saturated fat content, trans-fat free and high polyunsaturated fatty acid content. In this sense, the objective of this work was to structure sunflower oil in an high internal phase emulsion (HIPE) using pea protein (PP) as emulsifier and different polysaccharides (carrageenan (CG), xanthan gum (XG), gum Arabic (GA), sodium alginate (AL), pectin (PC), gellan gum (GG), locust bean gum (LBG) and tara gum (TG)) as stabilizers. 60/40 Oil-in-water emulsions were made with a protein:polysaccharide ratio of 4:1, and then the samples were oven-dried to obtain the HIPEs. The emulsions’ droplet size was between 13.13 and 25.02 μm in agreement with the optical micrographs obtained. After four weeks of storage at 5 °C, PP:GG, PP:AL and PP:GA were the most unstable emulsions (oil loss > 11%). Concerning HIPEs, only the PP:XG and PP:TG formulations presented creamy and uniform appearance, with minimal oil loss (0.89 and 1.72%, respectively). The other HIPEs (PP:CG, PP:GA, PP:AL, PP:PC, PP:GG and PP:LBG) were less stable, with the formation of agglomerates and oil loss between 34.72 and 75.38%. All the emulsions and HIPEs presented shear-thinning behavior, and the viscoelastic modules were little dependent on the frequency. The PP:CG emulsion and PP:XG e PP:TG HIPEs were the most stable systems. They can be interesting for application as fat substitutes in food formulations.