Investigating the physicochemical, rheological, and sensory properties of low‐fat mayonnaise prepared with amaranth protein as an egg yolk replacer

Abstract

This study investigated the possibility of using amaranth protein isolate (API) as a plant‐based substitute for egg yolk (EY) in the preparation of low‐fat mayonnaise (LFM). The alkali extraction/acidic precipitation method was used to isolate amaranth protein; its functional properties were then studied. The results showed that besides its great water and oil absorption capacities, API had better emulsifying capacity and significantly higher (p < .05) emulsion stability at pH 2.0 than alkali pH values. Five mayonnaise samples with different API/EY combination ratios (%) (i.e., 0/0.75, 0.25/0.5, 0.375/0.375, 0.5/0.25, and 0.75/0) were prepared. The color, emulsion stability (ES), freeze–thaw stability (FTS), droplet size, structure, rheology, and sensory properties of samples were examined. API replacement showed no adverse effects on the L* value, ES, and sensory attributes (p > .05). Low API concentrations (0.25% and 0.375%) significantly (p < .05) increased the droplet size and decreased the FTS of LFM emulsion. High API concentrations (0.5% and 0.75%) had no significant effect (p > .05) on droplet size and formed emulsions with more tightly packed oil droplets. The Cross model was chosen best to describe the flow behavior of LFM samples (R2 = 0.99). The sample with 0.75% API had significantly (p < .05) the highest values of ηo (zero‐shear viscosity) and λ (relaxation time), indicating greater interaction between the emulsion particles. All samples showed a weak gel structure (G' > G"). In conclusion, API can be considered an appropriate substitute for EY in LFM production, which can benefit human health and offer a new strategy for preparing vegan products.