Optimized ultrasonic-NaDES extraction of anthocyanins, polyphenolics, and organic acids from chokeberry fruit with blueness and antimicrobial evaluation

Deep eutectic solvents (DESs) have been widely used in food processing in recent years, owing to their remarkable advantages. The aim of this study was to evaluate the potential of DESs for the recovery of bioactive components from chokeberry fruit. First, among the 10 different DESs, the DES that extracted the highest total individual phenolic content (TIPC) from chokeberry was determined. Then, ultrasonically assisted extraction conditions (ultrasonic amplitude, time, and temperature) were optimized by response surface methodology to obtain the maximum amount of TIPC using this DES. According to the results obtained, the natural deep eutectic solvent (NaDES) choline chloride: acetic acid (1:2, 30% water content) provided the highest yield for TIPC extraction and the optimum conditions for maximum TIPC extraction were determined as 100% for ultrasonic amplitude, 50 °C for temperature and 60 min for sonication time. The TIPC content of the extracts prepared with this NaDES was determined between 1740.26 and 3703.14 mg/kg. In addition, the individual organic acid and individual anthocyanin contents of the NaDES extracts, as well as their antioxidant and antimicrobial activities, were determined. Chlorogenic acid (1392.351–2361.48 mg/kg) among phenolic compounds, pyruvic acid (9361.35–47398.04 mg/kg) among organic acids and kuromanin chloride (69748.13–134668.24 mg/kg) among anthocyanins were the dominant compounds in NaDES extracts. However, the extracts showed varying levels of antimicrobial activity against Gram (+) bacteria, Gram (−) bacteria, and yeast-like fungi (Candida strains). Finally, the Blue Applicability Grade Index (BAGI) was used to evaluate the practicality/blueness potential of the chromatographic method used to determine the anthocyanin composition of the DES extracts. In conclusion, NaDES (choline chloride:acetic acid) can be an alternative solvent for the recovery of some individual phenolics, organic acids and anthocyanins under different extraction conditions. In addition, the use of NaDES in the recovery of various functional compounds needed in food, cosmetics, pharmaceuticals, etc., is important for the promotion of sustainability and green technology.