Extraction of quercetin and rutin from fortified spreadable processed cheese

Abstract

A functional spreadable processed cheese (SPC) containing quercetin or rutin was produced by melting the ingredients at 85 °C for 2 min, and the retention rate of both flavonoids and antioxidant activity of the SPC samples assessed. Ultrasound-assisted extraction of quercetin and rutin from SPC to methanol (99.9% and 50%, v/v) for 30 min, respectively, was found to be optimal extraction procedure. Whereas a high recovery rate (92 %) for quercetin was achieved, only 64 % of rutin was recovered from the SPC sample. The results have indicated that rutin was thermally unstable during the melting process. SPC with quercetin or rutin exhibited effective radical-scavenging activity and possessed strong ferric reducing antioxidant potential. These results suggest that spreadable processed cheese may serve as the functional product.