STRUCTURAL INTERACTIONS BETWEEN CITRUS-FIBRE AND FRUIT-BASED SYSTEM FOR THE FORMULATION OF EMULSIONS

The citrus production is developed worldwide, they are utilized not just for fresh consumption but also processed to extract juice, essential oils, and pectin. Despite most of the fruit's insoluble components being discarded post-processing, researchers have focused on repurposing them for textiles, fertilizers, or biomass for fermentation. Although this insoluble residue is food-grade, it is not considered novel food. In Italy, it is commercialized as liquid pectin offering cost advantages and innovative ingredient possibilities. Citrus fibre can stabilize low pH emulsions with high thermal resistance. It can enhance mouthfeel and swallowing, making it suitable for the elderly or people suffering from dysphagia. The rheological properties of citrus fibre emulsions were investigated, comparing its interaction with apricot puree against a water-based system to isolate the fibre's effects. The nutritional components of citrus fibre and apricot puree were carefully characterized, correlating them with individual and combined properties. Technological attributes (OBC and WBC) and emulsifying capacity were evaluated for citrus fibre. The emulsions were prepared at different concentrations of sunflower oil and citrus fibre. Rheological properties were assessed via amplitude and frequency sweep tests to assess interactions between components and investigate the microstructure. Citrus fibre exhibited remarkable emulsion stability. Its behaviour varied significantly between water-based and fibre-based systems. Increasing fibre in water-based systems led to proportionally reduced oil release and rheological stability. Conversely, in apricot-based samples, high fibre content enhanced the oil separation due to the interaction between fibres but it increased the resilience of the emulsion structure. Research on citrus fibre in fruit-based emulsions uncovered insights for functional food development. By using a fruit puree, it's possible to modulate the properties of the fibre, resulting in unique rheological behaviour. Further study should delve into the interaction between fibre, fruit puree, and lipophilic and hydrophilic micronutrients that can be incorporated into the emulsion.