Extraction of anthocyanins from cranberry pomace using HIUS and NADES: Antioxidant and antifungal activity

This study explored the use of high-intensity ultrasound (HIUS) with natural deep eutectic solvents (NADES) to extract anthocyanins from cranberry pomace ( Vaccinium macrocarpon ) for potential antifungal applications. Extraction of cranberry pomace anthocyanins was optimized by varying HIUS power levels and times. Total anthocyanin content, total phenolic content and antioxidant activity of the extracts were determined. The choline chloride + glycerol mixture yielded 0.77 mg Cy3GE/g of total anthocyanins, comparable to ethanol (0.86 mg Cy3GE/g). Similarly, the glucose + lactic acid mixture achieved total phenolic content of 21.9 mg GAE/g similar to ethanol extraction. The choline chloride + glycerol mixture demonstrated approximately 20 – 48% inhibition against fungal growth on Pyrenophora tritici-repentis and Fusarium graminearum . The extracts appeared to suppress pigment formation in Fusarium graminearum , which may indicate inhibition of secondary metabolite production related to its pathogenicity. As a comparison, bilberry anthocyanin powder demonstrated significant antifungal activity, with 400 mg/L inhibiting Fusarium graminearum and Pyrenophora tritici-repentis by 23% and 55%, respectively. This research underscores the potential of anthocyanins and green extraction methods to develop sustainable antifungal agents for wheat. • Anthocyanins of cranberry pomace were extracted with high-intensity ultrasound (HIUS). • NADES with pH 2-4 and viscosity < 20 mPa·s showed high anthocyanin yields. • HIUS anthocyanin extraction was better than pressurized fluid extraction. • HIUS energy use for anthocyanin extraction was based on power, time and yield. • Choline chloride–glycerol mixture showed inhibitory effects on fungal strains.