Characterization of emulsions based on oleogels structured with commercial and recovered sunflower waxes

Abstract

The aim of this work was to compare textural and rheological properties of emulsions prepared using oleogels of high-oleic sunflower oil (HOSO) with commercial (CW) or recovered sunflower waxes (RW) obtained from sunflower oil winterization waste. Three concentrations of structurant (2, 3.5 and 5%wt/wt oleogel) were evaluated keeping the amount of remaining components constant, with the final objective of developing a product similar to a commercial margarine.Samples were prepared at controlled temperature and stirring. First, a molten oleogel was prepared by hot mixing HOSO, wax (CW or RW) and lecithin. Second, an aqueous solution containing salt, skim milk, EDTA, and potassium sorbate was also prepared. Afterwards, these two phases were homogenized to create the emulsion and subsequently stored at 5°C for 24 h allowing the obtention of a semi-solid material. Texture profile analysis and oscillatory frequency sweep tests were performed.The textural results at 3.5%wt of wax/wt oleogel showed that the hardness of CW emulsions (1.17±0.06 N) was greater than that of RW (0.76±0.01 N). This tendency was also obtained for the adhesiveness (2.25±0.28 vs 0.84±0.05N) and the other structurant concentrations. In addition, an increase in these properties was noticeable with the increase of wax content. Considering rheological results, the tendency was preserved, being G´ values greater for CW emulsions. It is important to note that emulsions of CW and RW showed rheological and textural properties comparable to those obtained in a commercial margarine, especially at high concentrations of wax.