Special Issue “Food Colloids: 3rd Edition”

This Special Issue features a collection of research papers following the 19th Food Colloids Conference, organized by the International Hellenic University and held on the 14–18 April 2024 in Thessaloniki, Greece. This international Conference focused on the theme “Using Colloid Science to Find New Sustainable Solutions in Food,” reflecting the growing importance of colloid science in addressing global challenges related to food sustainability, nutrition, and health. Nowadays, food colloids comprise a multidisciplinary platform where chemistry, physics, biology, and engineering converge to design functional food systems. The rational design of these systems relies on a deep comprehension of the molecular, physicochemical, interfacial, and colloidal properties of food ingredients, and how they are digested and delivered. This Special Issue showcases some of the latest advances in colloidal structures including emulsions, foams, gels, and nanoparticles, with applications ranging from nutrient delivery and food preservation to safety and sensory enhancement.

In the field of Bioactive Encapsulation and Delivery, new ingredients with bioactive properties are encapsulated using different matrices. Madybekova et al. used alginate-chitosan to efficiently encapsulate Bifidobacterium bifidum and Stevia leaf extract. This system, stabilized by strong polymer interactions verified by FTIR, targets the enrichment of a nutrient-rich acid whey beverage. Vaishnav et al. expslore carrageenan encapsulation of snail protein hydrolysates importantly enhancing their stability and bioactivity. Although immediate antioxidant activity and solubility were marginally reduced, the structural protection provided suggests suitability for controlled-release nutraceutical applications. Chitosan was also applied in combination with tripolyphosphate to produce nanoparticles to encapsulate ethanolic cashew leaf extract, as a source of polyphenols by Sinapapanya et al. The resulting formulation demonstrates strong antimicrobial and antioxidant activities importantly supporting the use of plant-based bioactives in food preservation.

Two contributions deal with Nanoemulsion Stability and Safety Assessment. On one hand Silva-Paz et al. develop optimized nanoemulsions of canola oil stabilized with soy lecithin and Tween 80 introducing protein gels to modify textural properties. Their rheological analysis suggests promising applications in food texture and stability enhancement. On the other hand, Hendawy et al. explore the safety of fish byproducts/lemon oil using nanoemulsions in aquatic models. Their findings highlight the need for balanced formulation strategies to ensure both efficacy and safety in food and pharmaceutical applications.

Anh et al. demonstrate the new advanced functionalization of colloidal silver nanoplates for food safety monitoring. The nanoplates, synthesized at room temperature, provided very high detection sensitivity as evidenced by an ultralow limit of detection for a critical antibiotic used in livestock, innovating in food safety monitoring.

New sustainable materials are evaluated in the final contributions, in which microalgae biomass is explored as a sustainable foaming agent by Georgiou et al. The protein-rich biomass extract displays a high foaming capacity and stability, suggesting high potential for commercial use in instant non-milk foam-forming beverages. Finally, Sharma et al. review the application of sodium alginate, a green, non-toxic biopolymer derived from seaweed, as an ideal source for edible fruit coatings. Its film-forming capacity and ability to retain moisture makes it a promising agent to develop coatings for shelf-life extension. Plant extracts or nanoparticles can be added to overcome their inherent hydrophilicity, also achieving enhanced antimicrobial and antioxidant effects.

The contributions in this Special Issue reflect the dynamic and interdisciplinary nature of food colloid science. From advanced encapsulation techniques to novel applications in food safety and functionality, the research presented here underscores the critical role of colloids in developing sustainable, health-promoting food systems. The Food Colloids Conference series reinforces importance of colloid science, inspiring further research and industrial applications and shaping the future of food.