Omega-6-fatty acid as octadecadienoic acid - 4d895

In the current application authorisation is sought under Article 10 for Omega-6-fatty acid as octadecadienoic acid, under the category/functional group 3(a) 'nutritional additives'/'vitamins, pro-vitamins and chemically well-defined substances having similar effect', according to Annex I of Regulation (EC) No 1831/2003. Authorisation is sought for pigs and bovines. According to the Applicant, the active substance is a methyl ester of conjugated linoleic acid (CLA-Me) equivalent to Omega-6-fatty acid as octadecadienoic acid (trans-10, cis-12-isomer), hereafter indicated as t10,c12-CLA-Me.

The feed additive is to be marketed either as a colourless to yellowish oily liquid or as an offwhite to beige solid formulation, to contain a minimum of 9 % of t10,c12-CLA-Me. The liquid product is intended to be mixed either in premixtures or added directly to feedingstuffs, while the solid formulation is specifically intended to be added directly to feedingstuffs for bovines only. The Applicant proposed a maximum concentration of t10,c12-CLA-Me in feedingstuffs of 0.5 %.

For the quantification of t10,c12-CLA-Me in the feed additive the Applicant submitted a single-laboratory validated and further verified method based on Gas Chromatography coupled to Flame Ionization Detector (GC-FID). Experiments data were provided in the frame of the validation and verification studies. The precision results derived from the validation and verification studies range from 0.14 to 0.65 %. Based on these satisfactory performance characteristics, the EURL recommends for official control this GC-FID method to quantify t10,c12-CLA-Me in the feed additive.

For the quantification of t10,c12-CLA-Me in premixtures and feedingstuffs the Applicant submitted a single-laboratory validated and further verified method based on High Performance Liquid Chromatography coupled to UltraViolet detection (HPLC-UV). The data presented indicated an acceptable method performance profile. However, due to the limited number of available data, a statistical evaluation was not possible. Therefore the EURL could not comment on the suitability for official control of the HPLC-UV method presented to quantify the total t10,c12-CLA-Me content in premixtures and feedingstuffs.

However, in the frame of the additional request from DG SANTE concerning the method for premixtures and feedingstuffs, the Applicant conducted additional experiments and submitted the supplementary information for the EURL evaluation. 

The additional results from the validation and verification studies confirmed acceptable performance of the method for the precision and recovery rate. The small differences observed for the mean values of the target analyte in the validation and verification study respectively were considered negligible and therefore sufficient transferability could be demonstrated.

Further testing or validation of the methods to be performed through the consortium of National Reference Laboratories as specified by Article 10 (Commission Regulation (EC) No 378/2005) is not considered necessary.

Recommended Method

as of:

Commission Implementing Regulation (EU) 2023/60

For the determination of Omega-6-fatty acid as octadecadienoic acid (trans-10, cis-12- isomer) in feed additive:

- Gas Chromatography coupled to Flame Ionization Detector (GC-FID)

For the quantification of CLA (t10,c12)-methy­lester in premixtures and feedingstuffs:

- High performance liquid chromatography coupled to spectrophotometric detection (HPLC-UV)