Throughout the world, consumer interest in fish and fish product consumption is increasing drastically (Tacon 2020). Conversely, fish farming and capture could also increase to fulfill the market n...

The alginate, a naturally occurring polymer, is mainly obtained from brown algae such as Laminaria, Macrocystis and Aspirin. This review shall examine the sources, processes and uses of alginate, with a focus on modern, high-tech extraction techniques. Although conventional alkaline extraction is still widely used, newer techniques such as supercritical CO2 extraction, microwave assisted extraction (MAE) and ex-traction by ultrasound are viable alternatives because of their higher efficiency, low environmental impact and scalability. Alginate is useful for applications in the food industry such as texture modification, food coating and encapsulation of bio-active substances because of its functions such as glazing, film-forming and stabilization. Vigorifyingly, vitamins, polyphenols, probiotics and essential oils can be encapsulated for increased stability, bioavailability and controlled dispersion. Alginate is also considered an environmentally friendly substitute for food packaging because of its potential as a sustainable and biodegradable material. The review focuses on recent studies on the bio-activities of alginate and its potential for use in the formulation of pharmaceuticals and functional foods. Despite these developments, more studies are needed to optimise the extraction of alginate, to improve knowledge of its biological activity and to explore new applications in food and other areas. This in-depth review highlights the growing importance of alginate in the food industry and its potential for future innovation in sustainable food technologies.

The valorization of fruit wastes provides a sustainable approach to producing nutrient-rich substrates for microbial applications. Characterizing their compositional and structural properties is essential for evaluating potential use in single-cell protein (SCP) production. This study investigates D-optimal mixture-designed substrates derived from banana peel, mango peel, and avocado seed, focusing on chemical composition, structural features, and functional indices. Proximate analysis revealed high carbohydrate content (~ 82%), moderate reducing sugars (20.6–23.1 g/100 g DM), low moisture (~ 7%), and consistent protein and mineral levels, indicating substrate stability. Structural characterization showed total lignin content of 7.07–8.26%, predominated by acid-insoluble lignin, while soluble sugar profiling confirmed the dominance of fermentable hexoses (glucose: 7.6–9.3, fructose: 6.6–8.1 g/100 g DM). Functional indices, including C/N ratios (27–30) and hexose/pentose ratios (~ 1.9), indicated the metabolic potential of the mixtures, and multi-response optimization suggested an optimal blend (46% banana peel, 22% mango peel, 32% avocado seed; R² > 0.97). These results demonstrate that D-optimal mixture design can produce reproducible, nutrient-balanced substrates with defined structural properties. While the study establishes a foundation for potential SCP applications, actual microbial utilization and fermentation performance remain to be experimentally evaluated.