Extraction of lignans, proteins and carbohydrates from flaxseed meal with pressurized low polarity water

This study examined the application of pressurized low polarity water (PLPW) extraction of lignans, proteins and carbohydrates from defatted flaxseed meal. Key processing conditions included temperature (130, 160, 190 degrees C), solvent pH (4, 6.5 and 9), solvent to solid ratio (90, 150 and 2 10 mL/g) and introduction of co-packing material (0 and 3 2 glass beads). The addition of 3 g glass beads increased the yields for all target compounds. The maximum yield of lignans (21 mg/g meal) was obtained at 170 degrees C with solvent to solid ratio of 100 mL/g meal at pH 9. Optimal conditions for protein extraction were pH 9, solvent to solid ratio of 2 10 mL/g meal and 160 degrees C. Total carbohydrates recovery was maximized at 215 mg/g meal (50% recovery) at pH 4 and 150 degrees C with solvent to solid ratio of 2 10 mL/g meal. The increase of temperature accelerated extraction, thus reducing solvent volume and time to reach equilibrium. For the extraction of proteins and carbohydrates, however, a temperature of 130-160 degrees C is recommended, as proteins and carbohydrates are vulnerable to thermal degradation. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.