Abstract
Micronised apple and mandarin bagasse were evaluated as natural and sustainable alternatives to synthetic emulsifiers for oil-in-water emulsion production. The study involved the characterisation of both by-products in terms of their bioactive compounds (total phenolic content, antioxidant activity, total carotenoid content) techno-functional properties (water-holding and oil-holding capacity) and microstructure (Field Emission Scanning Electron Microscopy). Four emulsions were then formulated using each type of bagasse at two pH levels (native and acidic). The emulsifying activity index (EAI), kinetic stability, and microstructure (Light Microscopy) were analysed to assess their emulsifying performance. Mandarin bagasse showed higher levels of total phenolics, antioxidant activity, and carotenoids, and apple bagasse demonstrated superior water- and oil-holding capacities. Regarding the emulsions, those stabilised with mandarin bagasse at acidic pH showed the highest EAI and kinetic stability, as well as the smallest and most homogeneous fat globules. These findings underscore the significant influence of pH and by-product type on emulsion performance. The main novelty of this study lies in demonstrating the potential of micronised raw mandarin bagasse as a clean-label, sustainable ingredient for emulsion stabilization, eliminating the need for added emulsifiers and supporting innovation in the food industry.