Extraction of antioxidant polyphenolic compounds from peanut skin using water-ethanol at high pressure and temperature conditions

BODOIRA ROMINA; ROSSI YANINA; MARIANA MONTENEGRO; DAMIÁN MAESTRI; VELEZ ALEXIS

JOURNAL OF SUPERCRITICAL FLUIDS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 128 p. 57 - 65

0896-8446

This study evaluates the feasibility ofusing sub-critical water extraction (SWE) processes to  obtain antioxidant phenolic compounds from peanut skins. Theoreticalmodels were tested  against experimental data in order tooptimize extraction conditions and antioxidant activity of  target compounds. The maximum concentration of total phenolics was achieved by using 60.5 %  ethanol as co-solvent, at 220 °C extraction temperature and 7 g/minsolvent flow. Under these  extraction conditions, a large number and variety of polyphenolswere identified. Phenolic profile  was dominated largely by monomeric andcondensed flavonoids, particularly procyanidin and  proanthocyanidin oligomers. Extracts obtained under those conditionsalso gave thebest radical scavenging capacities, which were higher to those reached by usinga synthetic antioxidant  (BHT, butylhydroxytoluene). Kinetic studies showed a highextraction rate of polyphenols until  the first 30 min of extraction, and itwas in parallel with the highest antioxidant activity.