Oenothera species and Borago officinalis: sources of gamma-linolenic acid.

Seed samples of 23 Oenothera species (O. biennis and O. lamarckiana in particular) and of B. officinalis, cultivated in 1986, were analysed. In B. officinalis, 7.1% (by weight) of gamma -linolenic acid (GLeA) was found in the whole seed whereas in Oenothera species the average was 2.3%. The mean content of oil in the seeds was 30.8 and 21.2%, respectively. The GLeA content was positively correlated with the seed oil content. The fatty acid composition of Oenothera oils showed only little variation between the different species grown in a particular year. The soil type, sand or clay, did not significantly influence the GLeA and other fatty acid contents of Oenothera species. It was concluded that the production of GLeA from B. officinalis can be as much as 3 times that in Oenothera species on the basis of similar seed yields for both crops and disregarding the poor seed retention of B. officinalis. The high level of GLeA emphasises the higher quality of Borago oil, in comparison to that of Oenothera, when used to compensate a lack of GLeA in man caused by Delta 6-linoleic desaturase deficiency diseases. (Abstract retrieved from CAB Abstracts by CABI’s permission)