Cheng LYe AYang ZHemar YSingh H2024-04-232024-07-252023-07-132024-04-232024-07-252023-12Cheng L, Ye A, Yang Z, Hemar Y, Singh H. (2023). Formation and properties of highly concentrated oil-in-water emulsions stabilised by emulsion droplets. Food Hydrocolloids. 145.0268-005Xhttps://mro.massey.ac.nz/handle/10179/7069670% (v/v) concentrated emulsion has been prepared using Ca2+-cross-linked sodium caseinate particles (Ca-CAS) or Ca-CAS coated nano-sized primary emulsion droplets as emulsifiers. The primary droplet-stabilised emulsion (DSE) was compared with the conventional Ca-CAS stabilised-emulsion (PSE) in terms of viscoelasticity as affected by aging (30 days) and heating (80 °C, 30 min) at pH 5.8 and 7.0. DSE at pH 5.8 showed the highest complex modulus (G* = 1174 ± 39 Pa), approximately was six-times higher than other emulsions (G* ≤ ∼250 Pa) due to the thick emulsifier layer consisting of primary droplet increasing the effective volume faction of core droplets by a factor of ∼1.21. After aging, G* of DSE at pH 5.8 increased to 1685 ± 68 Pa, while G* of other three emulsions were ∼400 Pa. After heating, G* of DSE reached 1801 ± 69 Pa and 1312 ± 205 Pa at pH 5.8 and pH 7.0, respectively, while G* of PSE were ∼600 Pa at both pHs. The possible mechanism for aging-induced gelation was the gravity-driven microphase separation, in which the droplets flocculate together with the entrapped aqueous phase increasing the effective volume fraction. The heat-induced gelation was attributed to the increase in droplet interactions through protein aggregates and/or primary droplets forming three-dimensional networks at elevated temperature. This study suggests that the mechanical strength of food-grade concentrated emulsions can be effectively improved using nano-sized primary emulsions as emulsifying agent and can be further modulated by aging or(c) 2023 The Author/sCC BY-NC-ND 4.0https://creativecommons.org/licenses/by-nc-nd/4.0/Droplet-stabilised emulsionInterfacial structureCalcium caseinate particlesEmulsion gelsRheologyJournal article10.1016/j.foodhyd.2023.1090591873-7137journal-article109059S0268005X23006057