A GLC method was developed for detection of diacetyl (2,3-butanedione) and acetoin (3-hydroxy-2-butanone) in orange juice. Retention times for diacetyl and acetoin were 2.8 ± 0.03 and 6.8 ± 0.02 min, respectively. Concentration by distillation was essential to detect small quantities by GLC of diacetyl but was ineffective for acetoin. A linear response of diacetyl concentration to peak area was observed between 0.05 and 0.5 ppm. The peak areas at 0.05 and 0.5 ppm diacetyl were 1242 ± 203 and 20142 ± 1120, respectively. Elevating the column temperature and decreasing the carrier gas flow rate, increased the limit of detection for acetoin from ≥ 100 ppm to ≥ 10 ppm, but diminished the resolution of the diacetyl peak from juice volatiles.