Determination of proline in honey
What you need to know about the determination of proline in honey?
Proline is secreted by the hypopharyngeal glands of bees, while its content in honey depends on the processing time of nectar by bees. Indirectly, proline levels also reflect the botanical origin of honey. As in the case of enzymes in honey (diastase, invertase), low proline values indicate possible adulteration of honey.
The concentration of proline is expressed in mg/kg of honey.
The Council Directive 2001/110/EC of 20 December 2001 does not set a minimum level for proline in honey. However, a proline concentration < 180 mg/kg is an international indication of immature honey or indicates possible adulteration.
There is no legal limit for the determination of proline content in honey, however its testing is required by many honey suppliers and honey packers in the market.
The amino acid content of honey is close to 1% (w/w), with proline being the predominant amino acid accounting for 50-85% of the total amino acids.