Disodium 5'- guanylate 2b627i

In the current application an authorisation is sought under Article 4(1) for disodium 5'-guanylate (GMP) produced by fermentation with Corynebacterium ammoniagenes KCCM 10530 and Escherichia coli K12 KFCC 11067 under the category/functional group 2(b) 'Sensory additives' / 'flavouring compounds' according to the classification system of Annex I of Regulation (EC) No 1831/2003. Specifically, the authorisation is sought for the use of the feed additive for all animal species and categories. 

The feed additive consists of a minimum of 97 % (w/w) of disodium 5'-guanylate (GMP) as an active substance, which is produced by fermentation with the strains of Corynebacterium ammoniagenes KCCM 10530 and Escherichia coli K12 KFCC 11067. 

The feed additive is intended to be used directly into feedingstuffs or through premixtures and in water for drinking with proposed maximum levels of 50 mg GMP/kg feedingstuffs. 

For the identification of GMP in the feed additive, the Applicant proposed the internationally recognised FAO JECFA monograph "disodium 5'-guanylate", which is comprised of various fit-for-purpose tests based on measuring solubility, absorbance signals in spectrophotometric measurements, presence of sodium, ribose and organic phosphate. 

The EURL recommends for official control the above mentioned FAO JECFA monograph for the identification of GMP in the feed additive. 

For the determination of GMP in the feed additive, flavouring premixtures and water the Applicant submitted a single-laboratory validated method based on high performance liquid chromatography coupled to UV detection (HPLC-UV). 

The following performance characteristics were reported in frame of the validation study for the determination of GMP content in the aqueous solution of the premixtures ranging from 7.8 to 182 mg/L: a relative standard deviation for repeatability (RSD_r) ranging from 0.3 to 0.6 %; and a recovery rate (R_rec) of 100 %. The lowest tested level of GMP in water (7.8 mg/L) was assigned by the Applicant as a limit of quantification (LOQ). In addition, the Applicant demonstrated proper selectivity of the method by submitting the chromatograms of flavouring premixtures, containing GMP and disodium 5'-inosinate.

Based on the available performance characteristics, the EURL recommends for official control the single-laboratory validated HPLC-UV method submitted by the Applicant for the determination of disodium 5'-guanylate (GMP) in the feed additive, flavouring premixtures and water.

The Applicant did not provide any method for the determination of GMP in feedingstuffs, therefore the EURL could not evaluate nor recommend any method for official control to determine GMP in feedingstuffs. 

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, as last amended by Regulation (EU) 2015/1761) is not considered necessary.

Recommended method

as of:

- Commission Implementing Regulation (EU) 2021/2093

For the identification of disodium 5'- guanylate (GMP) in the feed additive:

FAO JECFA monograph ‘disodium 5'-guanylate

For the determination of disodium 5'- guanylate (GMP) in the feed additive, flavouring premixtures and water:

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