Effect of plant protein emulsifiers and carriers on the physicochemical, structural, and oxidative stability of spray-dried pomegranate seed oil emulsions
Bahareh Eskandari, Seyed Hadi Peighambardoust, Khashayar Sarabandi
Abstract
This study compared apricot, walnut, and hazelnut kernel proteins (AKP, WKP, HKP) to whey protein concentrate (WPC) for stabilizing pomegranate seed oil-in-water emulsions before and after spray-drying. AKP demonstrated the most favorable emulsification properties, yielding an emulsion with a particle size of 262 nm, a PDI of 0.43, and a zeta potential of - 25 mV. Oil-in-water emulsions stabilized with AKP and WPC exhibited the highest solubility (62-66%), emulsifying activity (74-85 m2/g), emulsion stability (71-76%), foaming capacity (88-108%) and foaming stability (59-66%). The type of protein carrier significantly influenced the spray-dried emulsion's production yield, physicochemical properties, techno-functional characteristics, flowability, hygroscopicity, color, and particle size. The highest (60-62%) and lowest (41-44%) production yields were obtained for the samples produced with WPC/AKP and HKP/WKP, respectively. Encapsulation efficiency followed the order: WPC (85.9%) > AKP (82.2%) > HKP (75.4%) > WKP (70.0%). Peroxide values of spray-dried emulsions increased with storage temperature from 4 to 25 °C, with WKP and WPC exhibiting the highest and lowest oxidation, respectively. FT-IR analysis confirmed oil encapsulation within the carrier matrix. AKP shows promise as a plant-based alternative to WPC for emulsion stabilization and encapsulation of lipophilic bioactive compounds.