Effect of seed moisture content on flaxseed ( Linum usitatissimum L.) milling and milled product characteristics

BACKGROUND: Research was conducted to determine the effect of seed moisture content on flaxseed milling and milled product characteristics. Flaxseed with 55, 80, and 105 g kg −1 moisture contents were milled on a centrifugal cutting mill (CCM) configured with a 0.475 and 9.5 kg min −1 feed rate; a hammer mill configured with a blunt hammer face, 0.35 kg min −1 feed rate, 3.1 mm screen, and 2,795 m min −1 hammer tip speed; and a hammer mill configured with a sharp hammer face, 0.35 kg min −1 feed rate, 2.7 mm screen, and 3,870 m min −1 hammer tip speed. RESULTS: Fine‐particle fraction (≤600 µm) yield was greater from flaxseed with 55 than with 105 g kg −1 moisture content. Surface lipid content correlated positively with fine‐particle yield ( r = 0.82, P = 0.01). At each moisture level, the surface lipid extracted from the fine‐particle fraction was greater with 9.5 than 0.475 kg min −1 configuration of CCM and tended to be greater with the blunt than with the sharp hammer configuration of the hammer mill. CONCLUSION: Results indicated that flaxseed was more difficult to mill to a fine particle size at high than at low moisture content regardless of the mill configuration. Enhanced lipid oxidation was not detected in freshly milled flaxseed. Copyright © 2009 Society of Chemical Industry