| Abstract
| - Single-strength orange juice was irradiated with 0, 0.89, 2.24, 4.23, and 8.71 gGy of gamma radiationat 5 °C and then stored at 7 °C for 21 days. Volatile compounds, isolated by solid-phase microextraction, were separated and identified using a gas chromatograph equipped with a mass selectivedetector. The majority of the volatile compounds were terpenes, and the most abundant volatilecompounds were ethanol and limonene. Most volatile compounds were stable during the 21-daystorage period except geranial and neral which decreased over time. Irradiation reduced theconcentration of acyclic monoterpenes, such as geranial, neral, myrcene, and linalool 1 and 7 daysafter irradiation, but did not affect other monoterpenes, sesquiterpenes, or other volatile compounds.The reduction of acyclic monterpenes increased linearly with radiation dose, and correlated withan increase in thiobarbituric acid reactive substrates (TBARS) content. Reduction in the concentration of monoterpenes induced by irradiation was not significant 21 days after irradiation. Our resultsindicate that acyclic monoterpenes are sensitive to irradiation whereas most other volatile compoundsare resistant. Keywords: irradiation; orange juice; SPME; terpenes; volatile compounds
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