Increasing the efficiency of cumin essential oil extraction using cold plasma pretreatments.

BACKGROUND: Cumin (Cuminum cyminum L.) is one of the most important medicinal plants, and its essential oil (EO) varies between 2.5% to 5% depending on differences in climate. The extraction method plays a significant role in the market price of EOs. In this study, the effect of atmospheric cold plasma (ACP) pretreatments (using air and argon (Ar) gases) for different times on the EO yield and on the quality, color, surface morphology, and wettability of cumin seeds were studied.

RESULTS: The scanning electron microscope analysis results revealed that the formation of fissures and cracks caused by ACP pretreatments was directly related to increasing the efficiency of EO extraction. Comparing the two gas treatments, the highest total color changes ΔE were related to the Ar and the lowest to the air treatment, and the highest amount of browning index was related to the Ar ACP pretreatment. In general, the ACP pretreatments improved the extraction efficiency compared with the control, so that the highest increase was observed in the Ar ACP pretreatment at the rate of 44%. Ar ACP pretreatments were observed to have a higher extraction efficiency than air ACP did. In the Ar ACP-treated samples, cumin aldehyde, as the most important component of EO, was increased compared with the control (47.9-56.4%).

CONCLUSION: The data obtained in this study showed that ACP pretreatment of cumin seeds could increase EO extraction efficacy. Thus, ACP could be a promising technique to enhance the cumin seed EO extraction. © 2024 Society of Chemical Industry.