Changes in Volatile Compounds of γ-Irradiated Fresh Cilantro Leaves during Cold Storage

Consumption of salsas and dishes containing cilantro has been linked to several recent outbreaks of food-borne illness due to contamination with human pathogens. Ionizing irradiation can effectively eliminate food-borne pathogens from various vegetables including cilantro. However, the effect of irradiation on aroma of fresh cilantro is unknown. This study was conducted to investigate the effect of irradiation on volatile compounds of fresh cilantro leaves. Fresh cilantro leaves (Coriandrum sativum L) were irradiated with 0, 1, 2, or 3 kGy γ radiation and then stored at 3 °C up to 14 days. Volatile compounds were extracted using solid-phase microextraction (SPME), followed by gas chromatographic separation and mass spectra detection at 0, 3, 7, and 14 days after irradiation. Most of the volatile compounds identified were aldehydes. Decanal and (E)-2-decenal were the most abundant compounds, accounting for more than 80% of the total amount of identified compounds. The amounts of linalool, dodecanal, and (E)-2-dodecenal in irradiated samples were significantly lower than those in nonirradiated samples at day 14. However, the most abundant compounds [decanal and (E)-2-decenal] were not consistently affected by irradiation. During storage at 3 °C, the amount of most aldehydes peaked at 3 days and then decreased afterward. Our results suggest irradiation of fresh cilantro for safety enhancement at doses up to 3 kGy had minimal effect on volatile compounds compared with the losses that occurred during storage. Keywords: Irradiation; cilantro; volatile; storage