Color Measurement of Flax Retted by Various Means

Abstract

Color measurements are made of various kinds of flax retted by dew, water, or enzymes. Two sets of samples are analyzed under different conditions using different spectropho tometers and by reflectance in the visible and near infrared spectral regions. Sample set one consists of 55 samples of various flax types retted by traditional dew and water methods and various experimental enzyme retted samples. Means and standard deviations of CIELAB color values for each of the classes are displayed as spheroid plots. The enzyme retted fiber flax class forms a separate group that is substantially lighter and slightly yellower than dew retted flax. Water retted flax is intermediate between dew and enzyme retted flax, but tends to be closer to dew retted flax. Near infrared spectra vary with different cleaning methods to remove shives from fibers. A second set of 16 samples consists of dew, water, and spray enzyme retted samples, the latter samples also analyzed with regard to subsequent cleaning processes. CIELAB and Hunter Lab methods provide similar comparisons, although CIELAB values are higher within treatments. Enzyme retted fibers tend (P > 0.05) to be lighter and yellower than water retted ones. None of the flax fibers are as light as the cotton samples included for comparison. The Δ ECIELAB values are 8.8 between dew and water retted fibers, 13.6 between dew and enzyme retted fibers, and 4.9 between water and enzyme retted fibers. Factors that affect the color of enzymatically retted flax fibers are prior microbial activity, shive content, and fiber fineness. These color methods could form the basis for developing a color standard for short staple flax fibers.