Green Technologies for Circular Valorization of Agri-Food Bioresources

The increasing generation of agri-food waste has intensified the need for sustainable management strategies that support circular economy principles. Unlike previous studies addressing biomass valorization more broadly, this study focuses on food-oriented valorization pathways and the recovery of ingredients intended for food and nutraceutical applications. The study combines a systematic literature search with bibliometric analysis to investigate the use of green technologies for the circular valorization of agri-food bioresources in food-related applications. A search of the Web of Science Core Collection was conducted in June 2026 using keywords related to agri-food waste, by-products, valorization, green extraction, fermentation, bioconversion, and food applications. A total of 1,893 records were retrieved. After restricting the dataset to English-language articles and reviews and removing records belonging to the ongoing year and to non-food-related subject categories, 986 publications were retained for analysis. Bibliometric mapping and keyword co-occurrence analysis were performed using VOSviewer. The retrieved publications indicate that green extraction, fermentation, and bioconversion are the main technological approaches used to transform agri-food residues into value-added products. The frequently reported techniques included ultrasound-assisted extraction, microwave-assisted extraction, green solvent-based extraction, solid-state fermentation, and microbial fermentation. Regarding the raw materials used, fruit and vegetable residues, cereal by-products, and agro-industrial waste were the most commonly investigated bioresources. In the same time, the analyzed technologies facilitated the recovery of polyphenols, antioxidants, dietary fibre, carotenoids, proteins, and other bioactive compounds with potential applications in functional foods and nutraceutical products. The evidence from the selected studies suggests that recovering such ingredients from underutilized waste streams can improve resource efficiency, increase the availability of nutritional ingredients, and generate additional value without competing with conventional food or feed resources. The bibliometric mapping identified four dominant research themes associated with biorefinery concepts, fermentation technologies, biomass recovery, and the extraction of bioactive compounds. The findings indicate a gradual transition from waste disposal practices towards resource recovery and value creation. By combining a systematic literature search with bibliometric analysis, this study provides an overview of current research trends while drawing attention to challenges related to process scalability, techno-economic feasibility, and industrial implementation.