Journal of Colloid and Interface Science, Vol.563, 17-26, 2020
Emulsification of oil-in-water emulsions with eggplant (Solarium melongena L.)
Hypothesis: Eggplant is rich in polysaccharides. The mechanically homogenized eggplant flesh pulp (EFP) is expected to emulsify and stabilize o/w emulsions. The adsorption and network structure of the polysaccharides are hypothesized to contribute to the stability of emulsions. Experiments: Creaming index (Cl) and droplet size distribution were observed to evaluate the stabilities of EFP emulsions at different EFP concentrations (0.50, 0.75, 1.00, 1.25 and 1.50% w/v). Optical and fluorescence microscopy, confocal laser scanning microscopy and cryogenic scanning electron microscopy were conducted to observe the emulsification properties of the EFP-stabilized emulsions. In addition, rheological measurements were performed to reveal the EFP emulsions' rheological behaviours. Findings: The prepared oil-in-water emulsion emulsified by EFP remained stable at an EFP concentration of 1.50%. Rheological analysis illustrated that the emulsions had typical shear-thinning property and gel-like nature. The emulsification mechanisms were explained by the formation of an interfacial film adhered to the oil droplets and the coherent three-dimensional network formed by filament and sheet-like polysaccharide strands in the continuous phase. This finding may define a new kind of natural and dietary emulsifier for emulsion-based food, beverage, and pharmaceutical products. (C) 2019 Elsevier Inc. All rights reserved.