Camellia oil-based oleogels structuring with tea polyphenol-palmitate particles and citrus pectin by emulsion-templated method: Preparation, characterization and potential application

Abstract

Camellia-oil based oleogels were structured at a constant tea polyphenol-palmitate (Tp-palmitate) particles concentration of 2.5% (m/v) and varying citrus pectin concentration of 1.5, 2.5, 3.5 and 4.5% (m/v) using emulsion-templated method. Optical and laser confocal microscope were used to observe the microstructure of emulsions, dried products formed by freeze-drying the emulsions, and oleogels obtained by further shearing the dried products. Series of rheological measurements were performed to evaluate effects of citrus pectin concentration on the gel strength of emulsions and oleogels. The texture of dried products, and the oil binding capacity, oxidative stability and potential application of oleogels were characterized, respectively. Results revealed that citrus pectin concentration had significant effects on the physical properties of emulsions, dried products and oleogels due to the reinforcement from the interactions and entanglements of polymer. With the increase in the citrus pectin concentration, the stability and viscoelasticity of the emulsions increased, the hardness of the dried products with more compact structure became larger, and the oil binding capacity and gel strength of the oleogels enhanced. Oleogels displayed a high gel strength of G′ > 17,000 Pa and a good thixotropic recovery when the citrus pectin concentration was higher 1.5% (m/v). The polyphenol-rich oleogels had high anti-oxidative activity. The hedonic score in overall quality of cakes prepared with oleogels replacement of butter and that of cakes with butter were 21.49–27.58 and 32.03, respectively. This research gave a reference for preparing oleogels with food-approved polymer and provided more information for their potential application as substitution of solid fats.