Extraction of oil from meadowfoam flakes

摘要

As part of a program to improve meadowfoam seed processing, the authors examined the effects of seed moisture, seed temperature, and flaking roll opening on oil extraction efficiency in meadowfoam flakes. Flakes were prepared using a Wolf Mill with dual horizontal, unheated 12-in. diameter rolls. Roll openings of 0.005, 0.013, and 0.020 in. (0.127, 0.330, and 0.508 mm, respectively) gave average flake thicknesses of 0.013, 0.021, and 0.031 in., respectively (0.330, 0.533, and 0.787 mm). Seed moistures of 9, 12, and 15% and seed temperatures of 65, 190, and 210 degrees F (18, 88, and 99 degrees C) chosen for flaking were known to provide a range of conditions suitable for enzyme inactivation during seed cooking prior to flaking. Experimental flakes were examined for extractable oil content (petroleum ether extraction); this was compared to total oil content (31.5%) determined on finely ground flakes. Roll opening was the dominant variable determining Rake thickness, the primary parameter affecting oil extraction efficiency. Thus, the thinnest flakes at 0.013 in, were only slightly less extractable (29.8%) than finely ground flakes (31.5%), but intermediate (0.021 in.) and thick (0.031 in.) flakes were significantly less extractable (28.0 and 26.0%, respectively). There was a slight but significant (P < 0.01) trend toward thicker flakes with increasing seed moisture (15 > 12 > 9%) during flaking. A similar trend to thicker flakes with increasing temperature was significant (P< 0.01) only for the thickest flakes produced at the largest roll opening (0.020 in.). Lower seed moisture and higher seed temperature significantly impacted extractable oil content of the thickest flakes, but negligibly affected extractability of the thinnest flakes. The authors conclude that meadowfoam flakes must be as thin as possible (e.g., <0.015 in.) for efficient oil extraction. Further, seed cooking temperatures >190 degrees F at moistures >10% and <15% that are adequate for efficient enzyme inactivation in the whole seed are also suitable for seed flaking. [References: 5]