Valorization of Cork Using Subcritical Water.
Granulated cork was submitted to subcritical water extraction/hydrolysis in a semi-continuous reactor at temperatures in the range of 120-200 °C and with a constant pressure of 100 bar. The influence of temperature on the composition of the cork extracts obtained was assessed-namely, their content of carbohydrates and phenolics. The extraction yield increased with the temperature, and this was associated with the decrease in the dielectric constant of water and the increase in its ionic product. Extracts composed of up to 36% phenolics were obtained at temperatures of up to 120 °C, with an antioxidant activity only two times lower than that of pure gallic acid, but in low amounts. Assays at higher temperatures generated extracts richer in carbohydrates and with a phenolics content of ca. 20 wt.% in comparatively far higher amounts. Neither the amount of suberin nor its structure were affected by the subcritical water treatment.
['Cunha|Mónica|M|0000-0002-3990-3456', 'Lourenço|Ana|A|', 'Barreiros|Susana|S|', 'Paiva|Alexandre|A|', 'Simões|Pedro|P|0000-0001-5295-8905']
D000975:Antioxidants D002241:Carbohydrates D005591:Chemical Fractionation D002851:Chromatography, High Pressure Liquid D006868:Hydrolysis D008031:Lignin D008055:Lipids D009682:Magnetic Resonance Spectroscopy D010636:Phenols D010936:Plant Extracts D018547:Plant Stems D029963:Quercus D017550:Spectroscopy, Fourier Transform Infrared D013696:Temperature D014867:Water
cork subcritical water carbohydrates phenolics antioxidant activity Quercus suber L.