Ultrasound-assisted preparation of wax-based composite gelator: Structural characterisation, in vitro antioxidant activity and application in oleogels

Abstract

In recent years, the development of zero-trans fatty acid products instead of traditional hydrogenated and high-unsaturated fatty acid animal and vegetable oils has been an increasing interest in the field of food. This paper focused on the ultrasound-assisted preparation of a novel wax-based composite gelator loaded with natural antioxidant to prepare oleogels with good storage oxidation stability. The preparation of the wax-based composite gelator was to first form the anthocyanin (ACNs) and soyabean lecithin (SL) complex, and then homogenized with beeswax (BW). A complex maximum association efficiency of 86.43 % was achieved when the combination was performed for 50 min at 40 °C and 270 W ultrasonic power, and exhibited higher lipophilicity. Moreover, structural analysis results revealed that ultrasonic-assisted treatment accelerated the formation of ACNs and SL ultrasonic complexes (ASUC) by the hydrogen bonding. The results of gelators indicated the ASUC-BW composite gelator showed the highest ACNs embedding rate of 72.91 % and better antioxidant activity. XRD analysis and thermogravimetric analysis demonstrated that ASUC-BW composite gelator maintained β′ crystal structure and had higher thermal stability due to physical interactions between ASUC and beeswax. Accelerated storage tests at 60 °C revealed that oleogels prepared by ASUC-BW composite gelator (ALO) had significantly lower peroxide values (PV) (14.0 mmol/kg) and thiobarbituric acid reactive substances (TBARS) (1.8 mg/kg). Overall, this paper demonstrates ultrasonic-assisted treatment is an effective way to improve dispersion and availability of ANCs in food rich in oil and can be further applied to developing novel high stability fatty food systems.