Abstract:

Citrulline in wines spontaneously reacts with alcohol to produce ethylcarbamate, which is well known to be carcinogenic. In this paper, a method is described for colorimetric determination of citrulline in wine based on Fearon reaction. The results showed that the optimal conditions were as follows: 350 mL of sulfuric acid, 200 mL of phosphoric acid and 50 mg of ferric chloride comprising a 1 L reaction system held at 100 ℃ for 5 min, followed by cooling to room temperature in the dark and detection at 530 nm. The detection limit of the method was 5μg/L. The precision RSDs of determining two red wine and one white wine (all of them freshly brewed) ranged from 2.4% to 3.2%. Mean recoveries in these 3 wines ranged from 96.9% to 106.6%. The method descried in this paper is accurate and reliable, and it is most suitable for determination of citrulline in wine.

Key words: spectrophotometric method, wine, citrulline, Fearon s reagents