A novel low-temperature procedure for oleogelation of heat-sensitive oils: Oleogels based on tucumã oil and ethyl cellulose

Oleogels are made by structuring oils with an oleogelator, e.g., ethyl cellulose (EC), and can be used as fat replacers in foods. Also, oleogels made from oils rich in bioactives, e.g., tucumã oil (TCO), could possess additional nutritional benefits. However, sensitive compounds are often degraded during the harsh conditions of most oleogelation procedures. Here we present an adapted low-temperature indirect method (IM) to structure TCO with EC, which is based on emulsification with aqueous ethanol as continuous phase, and the physicochemical properties are compared to oleogels with the same composition but produced by a direct method (DM) at high temperature. For IM, TCO was emulsified with EC ethanolic dispersions, followed by solvent removal and shearing. DM resulted in weak gels (G' < 10000 Pa), with low oil binding capacity (OBC) (12.63–66.26%), low carotenoid retention (CR) (20.7–31.6%) and complete depletion of α-tocopherol. Conversely, IM provided strong oleogels (G' > 10000 Pa), with high OBC (87.82–100.04%), CR (>95%) and α-tocopherol content (293–322 mg/kg). TCO oleogels with different physical properties and retention of sensitive compounds were obtained by DM and IM, showing the potential of IM oleogelation to preserve bioactives in the oleogels and producing healthier fat alternatives for the food industry.