Change of Fatty Acid and Glucosinolate Contents during Seed Development and Maturation of Meadowfoam in Relation to Seed Quality.

Change of Fatty Acid and Glucosinolate Contents during Seed Development and Maturation of Meadowfoam in Relation to Seed Quality

Jun Zhang and Sabry Elias, Oregon State University

ABSTRACT

White meadowfoam, Limnanthes alba Hartw. ex Benth. (Limnanthaceae) is an annual dicot oilseed crop grown in the Willamette Valley of Oregon. Its oil has unique fatty acid profile and useful industrial usages. After extracting the oil, its seed meal contains glucosinolate (GSL), which is metabolizd to isothiocyanates and nitriles, which have alleopathic effects and potential use as a bio-herbicide in organic farming. The objectives of this study was to measure the fatty acid and GSL levels during seed development and maturation to determine the optimum time to harvest the crop with the highest levels of fatty acid and GSL.  Seeds from two cultivars, Ross and MF189 were planted in two locations, Lewis Brown and Hyslop farms near Corvallis, Oregon. Soon after seed formation, seed samples were collected at two-day intervals until harvest. Seeds were analyzed for fatty acid and GSL contents during the last four weeks before harvest. The fatty acid content did not change after seeds reached physiological maturity (PM).  The GSL concentration reached the highest level at harvest maturity (HM) in both cultivars at the two locations. The GSL concentration was less at in 2014 than 2013. The results suggested that if the purpose of growing meadowfoam is to use the meal as a bio-herbicide, it is recommended to harvest the crop when it reaches complete HM, and not before that. The quality of meadowfoam seed (germination and vigor) as measured by germination and accelerated tests reached highest level at PM and did not change until HM.