Determination of naringin and neohesperidin in orange juice by liquid chromatography with UV detection to detect the presence of grapefruit juice: Collaborative study

Fifteen collaborating laboratories were sent 9 samples of citrus juice mixt ures as blind duplicates for determination of naringin and neohesperidin by liquid chromatography, Two sample pairs were 100% orange juice and did not contain any naringin or neohesperidin. The remaining 7 sample pairs contai ned naringin at levels ranging from 3.9 to 46.5 ppm and neohesperidin at le vels ranging from 0.14 to 35.6 ppm, Five sample pairs consisted of orange j uice mixtures containing 1, 3, and 5% grapefruit juice; 5% sour orange; and 5% K-Early citrus variety. Two sample pairs were orange juice spiked with naringin, neohesperidin, sodium benzoate, and potassium sorbate, Data were received from 13 laboratories. Data from 1 collaborator were eliminated bec ause the method protocol was not followed. Neohesperidin values from anothe r laboratory were also not used because of problems with a coeluting compon ent. Repeatability relative standard deviations ranged from 2.95 to 15.23% for naringin and from 3.00 to 11.74% for neohesperidin, Reproducibility rel ative standard deviations ranged from 11.34 to 31.94% for naringin and from 10.45 to 26.17% for neohesperidin, The method is reliable for detecting th e presence of grapefruit juice in orange juice as indicated by a finding of greater than or equal to 10 ppm naringin and less than or equal to 2 ppm n eohesperidin. The method was adopted First Action by AOAC INTERNATIONAL.