Determination of Furosine in Honey

A procedure is reported for the determination of ϵ ‐N‐L‐furoylmethyl‐L‐lysine (furosine) in honey. Furosine was quantified in acid hydrolysis by isocratic ion‐pair reversed phase liquid chromatography, using C18 column and UV detection at 280 nm. Furosine formation by sample hydrolysis with hydrochloric acid increased with a rise in concentration from 6 N to 11.37 N. Average recovery of furosine by this method was 98.6% under our study conditions. The coefficient of variation at 2.5 mg/100 g of sample was 4.23% and the limit of detection was ≤0.15 mg/100 g of sample. Heat treatment (70°C for up to 45 min) increased the furosine content from 3.76 to 5.99 mg/100 g honey (79.7–127 mg/g nitrogen). Furosine levels in honey ranged from 0.33 to 5.49 mg/100 g honey (12–144 mg/g nitrogen.)