From waste to worth: Valorization of second-grade fig (Ficus carica L.) fruits as a sustainable source of valuable compounds

Ficus carica L. (fig) is a key fruit crop in the Mediterranean region, widely consumed both fresh and processed (e.g., dried, in jams, or juices). Beyond their sensory appeal, figs are rich in bioactive compounds—particularly phenolic acids (e.g., chlorogenic, gallic, ferulic acids) and flavonoids (e.g., rutin, quercetin 3-O-rutinoside)—which are associated with various health-promoting properties (e.g. antidiabetic, hepatoprotective, anti-inflammatory etc.). Large volumes of by-products are generated during fig processing, including peels, leaves, seeds, and whole fruits unsuitable for fresh consumption due to minor defects (e.g., size, texture, or surface blemishes), despite their nutritional value. This study explores the potential valorization of these second-quality fig fruits as sustainable sources of natural antioxidants and colorants for use in the food and cosmetics industries. Dried whole figs were subjected to β-cyclodextrin-assisted extraction enhanced by ultrasound treatment. Extraction conditions—including sonication time, temperature, and β-cyclodextrin concentration—were optimized using response surface methodology (RSM). The extracts were evaluated for total phenolic content (TPC) and in vitro antioxidant activity using DPPH, ABTS, and CUPRAC assays. Results demonstrate the feasibility of using low-grade fig fruits as high-value raw materials, highlighting their potential in the development of novel functional foods and dietary supplements within a circular bioeconomy framework.