The Potential of Waxes to Alter the Microstructural Properties of Emulsion‐Templated Oleogels

Abstract

In this research two oleogelation methods, in casu wax‐based oleogelation and emulsion‐templated oleogelation, were combined. Emulsion‐templated oleogels are known to have a high elastic modulus. However, they also exhibit limited structure recovery after applying shear. Oil partially leaking out of the oleogels greatly limits their application potential in food products. Wax‐based oleogelation on the other hand, requires high wax concentrations to attain the required level of structuring, causing a waxy mouthfeel upon consumption. Still, contrary to emulsion‐templated oleogels, wax‐based oleogels do demonstrate high levels of structure recovery after shear. The goal of this research is to enhance the structure recovery of the emulsion‐templated oleogels by gelling the oil within the structured protein network with low concentrations of candelilla wax, preventing a waxy mouthfeel. The microstructure of the emulsions and corresponding oleogels is elucidated with polarized light microscopy and cryo‐SEM. The newly developed oleogels are characterized rheologically using oscillatory and shear recovery measurements and by performing temperature sweeps. The addition of waxes in the emulsion‐templated oleogels did not significantly influence the gel strength, but did strongly reduce the shear sensitivity of the oleogels, as was determined with shear recovery measurements and confirmed with oil binding tests. Practical Application: To assess the true potential of these newly developed oleogels, a shortcrust pastry is developed using the emulsion‐templated oleogels as an alternative for a vegetable oil‐based margarine. Creep‐recovery tests on the doughs revealed that the emulsion‐templated oleogels had a better structuring capacity compared to the doughs prepared with wax‐based oleogels. However, neither of the two oleogel types were capable of attaining a similar level of dough structuring compared to the vegetable oil‐based reference margarine. In conclusion, combining several oleogelation methods can increases their application potential by exploiting some of the advantages while attenuating some of the disadvantages of both alternative oil structuring techniques. This research article investigates the combination of emulsion‐templated liquid oil structuring with proteins (top, left) with wax‐based oleogels (top, right). The waxes are allowed to crystallize within the oil cells of the emulsion‐templated oleogel. These oleogels were subsequently used to prepare shortcrust pastries.

Oleogel Fabrication Based on Sodium Caseinate, Hydroxypropyl Methylcellulose, and Beeswax: Effect of Concentration, Oleogelation Method, and Their Optimization

“…However, a considerable increase in OBC was observed above this concentration. The similar results have been also reported by adding 1–5% candelilla wax (CW) to gel the internal fat phase of emulsion‐templated oleogels containing 2.5% soy protein isolate (SPI) in the study conducted by Tavernier et al (). They attributed this increase in OBC to retain the liquid oil by the protein stabilized and wax internal crystalline networks (Tavernier et al, ).…”

“…The similar results have been also reported by adding 1–5% candelilla wax (CW) to gel the internal fat phase of emulsion‐templated oleogels containing 2.5% soy protein isolate (SPI) in the study conducted by Tavernier et al (). They attributed this increase in OBC to retain the liquid oil by the protein stabilized and wax internal crystalline networks (Tavernier et al, ). The lowest OBC values were dedicated to oleogels containing either CN, HPMC, or BW alone due to the formation of weak network and lower oil structuring capacity than combinations of them.…”

“…Then, they were refrigerated at 5°C for 24 hours. Finally, the dried samples were sheared for 20 s using a home appliances chopper (Hamilton, FH‐140N, Canada with power rating 700 W, 220–230 V, and 50–60 Hz) to attain soft and fine oleogels (Tavernier et al, ). An example of oleogel was given in Fig.…”

“…The thixotropic behavior or structure recovery was also assessed by subjecting the oleogel samples and commercial shortening to a three‐interval thixotropy test (3‐ITT) at oscillatory strains of 0.1%, 50%, and 0.1%, and checking the changes in G´ values. In this study, the recovery percent of oleogels and commercial shortening was figured out as the percentage proportion of the G´ value at the termination of the third interval to that of at the initiation of first interval (Tavernier et al, ).…”

Structure and stability of edible oleogels prepared with different unsaturated oils and hydrocolloids

“…HPMC is an amphiphilic biopolymer derived from cellulose and is a stabilising additive (E464) in the food industry. Using HPMC as oleogelator is advantageous since it is inexpensive compared to more studied low molecular weight organogelators (Tavernier et al , ; Scholten, ) generally recognised as safe (GRAS) and has beneficial effects on health (Maki et al , ). However, there are limited studies considering the production of oleogels using HPMC, because of their hydrophilic nature.…”