Erucic acid is a naturally occurring contaminant present in the oilseeds of the Brassicaceae family of plants, which includes oilseed rape and mustard. Through plant breeding the levels have been reduced and Double Zero OSR varieties are required to have an erucic acid content lower than 2%, however in the past few years oilseed crushers have noted significant increases in the levels found in harvested seed. AIC do not view this problem as coming from certified seed, so investigation into the source is ongoing. AIC is part of a cross-industry working group for prevention and mitigation of the problem, and it is regularly discussed by the AIC Arable Committee and Seed Committee.
The potential causes are numerous, for example some weed seeds are naturally high in erucic acid (in charlock it is 31.7%) so could be contaminating the grain directly, or through hybridisation with the crop. It has also been suggested that volunteers from HOLL rapeseed (specifically grown for its high erucic content for use in industrial processes) could be contaminating later crops of low erucic oilseed rape. In addition farm saved seed is being looked at, because it stands to reason if harvested seed has high levels, drilling that seed will not reduce the level in subsequent harvest. In order to identify the cause of the problem, in 2016 and 2017 AIC requested surveys back from growers who had been affected by high erucic acid levels, and experienced the corresponding fines or rejections. Unfortunately from the information received there is no clear and consistent evidence as to where the issue originates, so there is no ‘smoking gun’. AHDB will be carrying out significant research in 2018 to provide answers on the origin.
2018 presents fresh challenges, as it is likely that oilseed rape will again have high erucic acid levels, but this issue will be made much more acute by an anticipated change in legislation that reduces the maximum allowable level in oil. The current EU limit is 5% erucic acid in oil for food uses (and significantly lower for infant foodstuffs), but this was set in 1976 and is out of step with other guidance such as that in the Codex Alimentaris and the US FDA which both set a limit of 2%. A new EU level of 2% is expected to come into force before harvest 2018.
Mitigation measures are being discussed by all parties, and increased testing will play a strong role. Identifying the source of this problem is a major industry priority, as significantly higher rejections would create problems all along the chain, affecting all AIC members involved with oilseed rape.