Oleogel-based fat structuring: functional, oxidative, and thermal stability of moringa seed, tiger nut, and garden cress oils with various waxes

Abstract

Abstract This study investigated the preparation and characterisation of oleogels made from moringa seed, tiger nut, and garden cress oils, structured with beeswax, carnauba wax, and sunflower wax at concentrations of 6%, 8%, and 10%, respectively. Moringa and tiger nut oils, rich in oleic acid (71.04% and 69.55%), showed good oxidative stability, while garden cress oil, with high linoleic (60.26%) and linolenic acids (11.55%), was more prone to oxidation. Moringa seed oil also had the highest α-tocopherol (55.02 mg/kg) and γ-tocopherol (90.32 mg/kg), boosting antioxidant capacity. Wax concentration improved oil-binding capacity, with garden cress oil at 10% beeswax achieving the highest retention (98.05%). Carnauba wax-based oleogels had the longest gelation times, and texture analysis showed increased hardness, with moringa seed oil-carnauba wax at 10% being the hardest. The lowest peroxide value (2.30 meq O2/kg) was observed in moringa seed oil-10% carnauba wax. Total phenolic content (19.0 mg gallic acid equivalents/g) and antioxidant activity (91.0%) were highest in moringa seed oil-10% carnauba wax. Differential scanning calorimetry and thermogravimetric analysis showed garden cress oil-carnauba wax had the highest thermal stability. Moringa seed oil-carnauba wax oleogels displayed the highest storage modulus and viscosity. Overall, wax-structured oleogels showed potential as functional fat substitutes in food applications.