Oxidative and Physical Stability of Vegetable Oil Oleogels With a Binary Mixture of Beeswax and Candelilla Wax

Abstract

Oxidative and physical stability of 3% and 7% beeswax-candelilla wax (BW-CDW, 1:1) oleogels prepared with flaxseed (FSO), soybean (SBO), and olive oils (OO) were evaluated during storage at 25°C and 4°C. Peroxide values (PV) and conjugated diene values (CDV) of BW-CDW oleogels were lower than bulk oils after storage at 4°C for 180 days, and those of 7% wax oleogels were lower than 3% wax oleogels, indicating the protection effect by oleogelation. In contrast, these oleogels had lower oxidative stability than bulk oils at 25°C, indicating the prooxidant activity of waxes. PV of 7% BW-CDW SBO oleogel increased slower than commercial margarine fat (CMF) at both storage temperatures, while its CDV increased faster at 25°C. Gel strength (firmness and cohesiveness) of oleogels decreased at both temperatures. Gel strength of CMF decreased faster than oleogels at 25°C, while it was steady at 4°C. Gel strength of OO oleogels dramatically decreased during storage at 4°C, which was likely due to large oil crystals formed that broke the wax crystal network at 4°C. Solid fat content and melting enthalpy of oleogels increased, indicating that new crystals formed during storage, which, however, did not provide higher gel strength. New spherulite crystals appeared during storage at 4°C, which might be the reason for decreased gel strength. Overall results indicated that BW-CDW oleogels had the oxidative and physical stability comparable to CMF, except for OO oleogels stored at 4°C.