Bioactivities of pilot-scale extracted cranberry juice and pomace.
Fresh cranberries were processed by two pilot-scale methods to recover juice and extracts from cranberry pomace. Press cake was extracted with three successive ethanol soaks followed by decanting in trial 1 versus one ethanol soak and solvent removal by decanting and compressing with the bladder press in trial 2. Yields and recoveries of juice, dry juice solids, press cake, press cake extractives (PCEs), polyphenolics and antioxidant capacity were determined relative to the input material of fresh cranberries or press cake. PCEs from both processes exhibited strong dose-dependant vasorelaxant effects on rat aorta rings with EC50 of 2.3-3.9 micro g/mL and Emax of 96-98%. PCEs contained three to four times the phenolic acids, tartaric esters and antioxidant activities plus five to 10 times the flavonols and anthocyanins of their respective juice powders. The polyphenolic levels were 121-142, 7-10, 9-11 and 10-19 mg equivalents of catechin, caffeic acid, quercetin and cyanidin-3-glucoside/g of extract, respectively. Antioxidant activities of the PCEs and juices were 201-296 and 64-75 mg trolox equivalents/g powder. Juice yields of 47-58% accounted for only 18-50% of the bioactives recovered from whole fruit. Sequential extraction of the press cake with 95% ethanol and removal of the extract with the bladder press favored high recoveries of polyphenolics with increased antioxidant and vasorelaxant benefits.