Ultra-Long-Chain Sorbitol Esters Tailoring Thermo-Responsive Rheological Properties of Oleogels

Abstract

Oleogels must replicate the rheological behavior of saturated fats at processing and consumption temperatures to maintain their physical stability and sensory acceptance. Thus, multicomponent oleogels present a promising approach since oleogelators can exhibit structuring and melting at different temperatures. The aim of the study was to produce a mixture of ultra-chain-long esters capable of structuring and modulating rheological behavior in response to temperature exposure. Therefore, enzymatic transesterification between sorbitol and fully hydrogenated crambe oil (FHCO) was performed to produce a mixture of ultra-long-chain sorbitan esters (SB) for efficient structuring of sunflower oil. SB generated in a reaction medium consisting exclusively of ethanol (60 °C, 200 rpm, 1:1 molar ratio) was selected for its high sorbitol consumption (~95%). While SB oleogels exhibited higher gel strength at 5 °C, at 25 °C, FHCO oleogels were stiffer, showing the gradual melting of SB oleogels evaluated by temperature-dependent rheological analyses and thermal properties. Oleogelation inhibited hydroperoxide formation compared to sunflower oil over 30 days. Results highlight the potential of multicomponent oleogels based on ultralong-chain esters for healthier and more stable high-lipid products. Modulating rheological thermoresponsiveness ensures physical stability under refrigeration while providing a texture similar to saturated fats during spreading and swallowing.

Keywords: esters; oleogelator; rheology; saturated fat; transesterification.

Figure 1

Pareto chart showing the effect of experimental conditions on sorbitan behenate (SB) synthesis.

Figure 2

Consumption of sorbitan behenate (SB) according to successive reuse of CALB in the SB synthesis.

Figure 3

FTIR spectra of sorbitan behenate (SB), sorbitol, and FHCO. Black dotted line black dotted lines indicate highlighted bands.

Figure 4

Frequency sweeps for FHCO, SB, and SM oleogels incubated at 5 °C (A) and 25 °C (B). Solid and open symbols represent elastic (G′) and viscous (G″) moduli.

Figure 5

Temperature sweeps of (A) FHCO, (B) SB, and (C) SM oleogels. Cooling (left) and heating (right) steps. Solid symbol (G′) and open symbol (G″).

Figure 6

Melting (left) and crystallization (right) for FHCO (A), SB (B), and SM (C) oleogels.

Figure 7

Macroscopic appearance and polarized light micrographs of oleogels. (A,D)—FHCO oleogel; (B,E)—SB oleogel; (C,F)—SM oleogel. Scale: 100 μm.

Figure 8

Peroxide value of SFO (control) and FHCO, SB, and SM oleogels after 0-, 7-, 15-, and 30-day(s) of storage at 25 °C. Different lowercase letters mean statistical difference between all samples for each storage time. Different capital letters mean statistical difference between the same sample for different storage times.