STUDY OF EXTRACTION OF QUERCETIN FROM PURPLE ONION (Allium ceppa L.) AND ITS USE AS A NATURAL FOOD PRESERVATIVE

The present work studied the solid-liquid extraction of the flavonoid quercetin from purple onion. Experimental studies of solvent, temperature, raw material mass per solvent volume and extraction time showed the best condition for leaching: ethanol 60% (v/v); 40°C; raw material mass (g)/solvent volume (ml) 1:10; 2 hours and 200 rpm shaking; with a quercetin recovery of 209.83 mgquercetin/graw material and 335.19 mgquercetin/gSST (Total Solid Soluble). With these values the complete extraction process was simulated with the aid of Aspen Plus® software. Starting from a base of calculation of 1000 kg/day of raw material it was obtained a production of 21.7 kg/day of quercetin, in the form of alcoholic extract 40 °BRIX. An ethanol recycle of 788.2 kg/day was estimated, requiring 17.8 kg/day of anhydrous ethanol and 94.3 kg/day of water in the process.