Processing of crambe for oil and isolation of erucic acid

Abstract

AbstractCrambe seed (Crambe abyssinica) is an excellent, recently established source of high‐erucic acid oil. Erucic acid has a number of important and potential applications. To develop this potential, a rapid bench‐scale method was desired whereby purified erucic acid in up to several 100‐g quantities could be produced from crambe seed. Using the method developed, oil was expressed from dried, intact seed; clarified, degummed, and bleached; and saponified and acidified to obtain the free fatty acids. Analysis by inductively coupled plasma of the free fatty acids showed negligible levels of phosphorus and most minerals. Erucic acid was twice crystallized from 95% ethanol at −14°C, resulting in a purity of 87.1%. This process yielded 365 g erucic acid crystals per kg bleached oil. Nuclear magnetic resonance analysis showed that the prepared erucic acid had an excellent pattern of correlation with a commercial standard. The time needed to convert 1 kg of crambe seed to erucic acid is about 48 h. Crystal filtration and drying stages under the current process conditions require 30% of the overall time. The method is suitable for producing adequate quantities of erucic acid for use in studies of its bench‐scale conversion. There is obviously, still, a fruitful field of work to be explored in the formalization of refining procedures for crambe oil. It seems that crambe is destined to continue expansion into the high‐erucic acid oil markets.