Effect of high voltage electrical discharges, heating and ethanol concentration on the extraction of total polyphenols and lignans from flaxseed cake

The aim of this work was to study the effects of high voltage electrical discharges (HVED), mild temperature (20-60 degrees C) and ethanol addition in water (0-25%) on the extraction of total polyphenols and lignans from whole and crushed flaxseed cake. HVED noticeably enhanced the aqueous and hydro-ethanolic extractions of total polyphenols from both crushed and non crushed flaxseed cake. The addition of ethanol had a synergic effect and increased the extraction efficiency. For the uncrushed cakes, the diffusivity of total polyphenols from the untreated samples was in the range of 1.1-1.8 x 10(-9) m(2)/s (without ethanol) and 3.2-5.9 x 10(-10) m(2)/s (with ethanol). The diffusivity of polyphenols from the HVED-treated samples was higher: 2.6-2.7 x 10(-9) m(2)/s (without ethanol) and 3.0-4.2 x 10(-9) m(2)/s (with ethanol). However, the results obtained for lignan extraction were lower than those found in the literature (around 20 mg SDG/g defatted flaxseed). (C) 2013 Elsevier B.V. All rights reserved.