30A-2 |
Occurrence and removal of chlorinated compounds in cold-pressed citrus oils |
E. R. WEISS and R. J. Braddock. Food Science and Human Nutrition, University of Florida, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred, FL 33850 Presence of unidentified halogenated compounds in some commercial cold-pressed citrus oils is a significant scientific and economic concern for the citrus and flavor industries. Studies of particular chlorinated compounds found in drinking water have proven many to be carcinogenic. Since 1999, at least one major beverage company will not purchase cold-pressed oils containing these halogenated compounds. It was hypothesized that these compounds were formed from a reaction of limonene, the major component of cold-pressed oil, with chlorine found in treatment water used in the oil recovery process and sanitizers used in post-harvest handling. Our objectives were to ascertain the source of these compounds, whether they are naturally occurring; or if they are a result of processing conditions, to determine where in the oil recovery process they are being produced, and establish optimum processing conditions for their elimination in the product. A method of analysis was established using GC/ELCD for detection of chlorinated compounds. Identification of the main halogenated compound found in cold-pressed citrus oils was determined to be 2-chloro-p-menthene-1-ol (CPMOL). Using a standard curve developed from a purified form of this compound we determined the relative concentrations found in some commercial cold-pressed oils. Results show a range of 1 to 50 ppm of CPMOL in citrus essential oils. Post-harvest fresh fruit treated with up to 200 ppm chlorine sanitizer was also found to be a potential source of contamination. No toxicological information has been published for CPMOL. Charcoal removal of chlorine from treatment water resulted in CPMOL-free oils. These results suggest that the presence of CPMOL in cold-pressed oils is a result of processing conditions and can be reduced through reduction of chlorine levels in treatment water. These findings will enable citrus oil processors to make the necessary changes to produce valuable CPMOL-free oil.
Session 30A, Citrus
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