Seed oils of Sisymbrium irio and Sisymbrium sophia as a potential non-edible feedstock for biodiesel production

Biodiesel production from non-edible oil feedstocks could partially alleviate the debate over the food vs. fuel crisis. In this work, seed oils of Sisymbrium irio L. and Sisymbrium sophia L. syn. Descurainia sophia L. Webb ex. Prantl were investigated as potential industrial non-edible biodiesel feedstock. The results revealed that the seeds had high oil contents, of 36.98% (S. irio) and 33.99% (S. sophia). The relatively high erucic acid content in the seed oils (i.e. 11.23 and 10.29%, respectively) showed that these oils could not be applied as edible oils. On the other hand, the low free fatty acid contents (0.44 and 0.34%) showed that seed oil of these species could be a suitable source for biodiesel production even in non-refined form. Linolenic acid was the dominant acid, making up 49.2 and 51.8% of the fatty acid profiles of S. irio and S. sophia, respectively. Such high linolenic acid content in both seed oils resulted in favorable physicochemical properties of the perspective biodiesels, i.e. higher degree of unsaturation, improved cold flow characteristics, and better viscosity. Overall, the seeds could serve as a non-controversial biodiesel feedstock, resulting in enhanced fuel properties while not posing any threats to food security.