Coconut oleosomes as a sustainable ingredient for food emulsion systems†

Abstract

Virgin coconut meal (VCM), a major by-product from the coconut milk processing stream, contains 30–40% oil, which seldom gets repurposed for food applications. In this study, we investigated the feasibility of VCM for the extraction of oleosomes and its suitability for the formulation of emulsion-based food systems such as vegan mayonnaise. Oleosome extraction parameters (pH 6.43 and feed-to-solvent ratio 1 : 1.96) were optimised using the response surface methodology. The extracted oleosomes contain 93.24 ± 1.53% of fat and 5.34 ± 0.3% of proteins, along with residual carbohydrates and moisture. Particle and morphological analyses indicated that oleosomes are monodisperse spherical particles with a mean diameter of 1.35 μm, and they are highly stable in the pH range of 6–9. The functional and thermal properties of oleosomes were interpreted through FTIR and DSC analysis. The colour profile of oleosomes is neutral with excellent whiteness, making them suitable for the formulation of food products. Rheological analysis of oleosome incorporated mayonnaise exhibited a uniform structured biphasic food matrix with soft solid-like consistency on par with commercial mayonnaise. Sensory analysis using a nine-point hedonic scale revealed that oleosome-based mayonnaise is more appealing than egg-based mayonnaise. Results from the above studies suggest that VCM is a suitable by-product for the extraction of oleosomes, and the extracted oleosomes can act as an emulsion with the potential to replace oil and emulsifiers in emulsion-based food products. The above process can be effectively applied for the extraction of oleosomes from cold-pressed meals/seed cakes.