Occurrence and Preclusion of Terpene Chlorohydrins in Citrus Essential Oils

: Screening commercial cold-pressed oils revealed the presence of terpene chlorohydrins, which may have quality and safety implications for end-users. Concentrations of (1R, 2R, 4R)-2-chloro-8-p-menthen-1-ol in some citrus essential oils ranged from less than 1 to 140 ppm. More than half of the oils tested contained less than 2 ppm of (1R, 2R, 4R)-2-chloro-8-p-menthen-1-ol. A pilot plant study used different concentrations of chlorinated water during the oil-recovery process. Cold-pressed oil, produced from a 30-ppm chlorine solution, contained (1R, 2R, 4R)-2-chloro-8-p-menthen-1-ol at detection threshold. The presence of (1R, 2R, 4R)-2-chloro-8-p-menthen-1-ol in citrus essential oils results from processing conditions and can be reduced through the reduction of chlorine levels in treatment water.