In the past few years, research efforts have focused on plant exploitation for deriving some valuable compounds. Extraction has been usually performed using petrochemical and volatile organic solvents, but nowadays, increased recognition of environmental pollution has prompted the utilization of green solvents as alternatives. Therefore, the aim of the present study was to exploit deep eutectic solvents (DES) (choline chloride: citric acid and choline chloride: glucose) as solvents for extracting valuable phenolic antioxidants from grapes. Investigation was conducted on ten grape varieties, observing seeds and skin as different matrix. Total polyphenol content (TPC) was determined by Folin-Ciocalteu spectrophotometric microassay. Antioxidant activity was investigated using four different tests and results were combined in a unique Antioxidant Composite Index (ACI) to reveal comprehensive information about this biological activity. Polyphenol compounds were identified and quantified with the aim of HPLC-diode array detector (DAD). Overall results support that DES (particularly choline chloride: citric acid) were comparable to conventional solvent, and in most cases even outperformed acidified aqueous ethanol (concerning extraction efficiency and antioxidant activity). Regardless of varietal distinctions, grape seeds have higher antioxidant capacity compared to grape skin, and such findings are according to their phenol compound concentrations.

Winemaking generates large quantities of grape waste consisting of seeds, skin and stalks. Given that grape seeds are a rich source of different bioactive compounds, the main goal of this research was to optimize grape seed phenol extraction using a Box–Behnken design. The following conditions were derived from the optimization process: sample:solvent ratio of 1:10 w/v, extraction time of 30 min and extraction temperature of 50 °C. In addition, a sustainable (green) approach for obtaining extracts was developed by comparing choline chloride:citric acid-ChCit (natural deep eutectic solvent (NADES)) and ethanol extraction methods with respect to phenol profiles and antioxidant activity. This study was conducted on seeds from eight different red grape varieties. Phenolic acids, flavan-3-ols and procyanidins were characterized using HPLC–MS/MS, and the concentration of procyanidin B1 was above 1 mg/g of dry weight in all analyzed samples. The contents of all phenol classes and antioxidant activities were found to not differ significantly between the solvents, but NADES was found to offer valuable advantages. Importantly, ChCit showed a strong affinity toward procyanidins and a strong correlation between antioxidant activity and quantified phenolic compounds.

The disposal of waste generated in the agri-food industry is one of the greatest challenges in achieving sustainable development. Although agri-food residues are a potential source of bioactive compounds with proven health benefits, they are largely unused and disposed of as organic waste. The recovery of bioactive compounds from agri-food waste to obtain products with high biological value, such as functional foods and nutraceuticals, is an idea that stems from the concept of bioeconomy and combines environmental issues with economically viable production. Some of the main agri-food wastes in Serbia that have the potential to be recycled into value-added products are apple, plum, grape, tomato, and beet pomace, and oilseed cakes. Bioactive compounds isolated from these wastes include polyphenols, fibers, essential fatty acids, minerals, various volatiles and pigments. This article focuses on the most common food wastes and the potential reuse of these undervalued material to produce value-added products such as functional foods, nutraceuticals or food additives.

Due to the presence of numerous bioactive compounds, including polysaccharides and polyphenols, mushroom-based food supplements are claimed to have many beneficial health effects. Despite their popularity, concerns have been raised in recent years over the quality of mushroom products, particularly regarding their non-standardized chemical composition. In this study, the ?-glucan and total phenolic contents, as well as the antioxidant potential of mushroom-derived supplements available on the Serbian market were analyzed. The obtained results, revealing considerable differences in ?-glucan and total polyphenol contents among these products, reflect variations in mushroom species, forms and recommended dosing regimens. A correlation between the total phenolic content and antioxidant activity was observed. The presence of other active ingredients, such as vitamin C, has contributed to antioxidant variability among the analyzed products. The obtained results indicate the need for the standardization of mushroom-derived food supplements to ensure their claiming effects.

Plants are sources of compounds with important effects on health, but plant-based food industry generates substantial waste amounts, especially in oil production. This study aimed to characterize flours derived from oilseed by-products, pumpkin, sunflower, and apricot seed residues, and compare them with conventional grain flours (white and whole wheat). Nutritional composition was analyzed with emphasis on amino acid profiles performed by ion chromatography. Mineral profiles were determined by ICP-MS. Total phenolics and antioxidant activity were assessed using in vitro colorimetric microassays. Oil press cake flours showed significantly higher levels of protein and fiber compared to wheat flours (p < 0.05), while the latter contained more carbohydrates. Among the examined flours, pumpkin and apricot seed flours stood out with the highest potassium, while sunflower seed flour led in calcium content. Despite higher polyphenol content in wheat flours, apricot seed flour exhibited the greatest antioxidant activity, likely due to its diverse profile of hydrophilic and lipophilic bioactive compounds. These findings highlight oil press cakes as nutritionally valuable ingredients for protein-enriched and other innovative food products, aligning with circular economy principles and promoting resource efficiency in the agri-food sector.