Boosting Cumin Oil Extraction with Cool Plasma Techniques

Jenn Hoskins
27th January, 2024

Boosting Cumin Oil Extraction with Cool Plasma Techniques

The Cumin (Cuminum cyminum) plant, source of Cumin Essential Oil

Photographer: Peter de Lange
Cumin is a widely used spice and has a long history in traditional medicine. Obtaining its essential oil (EO) – the concentrated aromatic compounds – can be costly, largely due to the extraction process. Researchers at Tarbiat Modares University[1] have been investigating whether atmospheric cold plasma (ACP) can offer a more efficient and cost-effective way to extract EO from cumin seeds. The core of the study involved exposing cumin seeds to ACP, a technology that uses ionized gas to alter the surface of materials. This isn’t about ‘cooking’ the seeds; ACP operates at near-room temperature. The researchers tested two different gases – regular air and argon – during the ACP treatment, and varied the duration of exposure. They then measured the amount of EO extracted from the treated seeds, as well as changes to the seeds’ color, surface structure, and how well liquids spread across them (wettability). The results showed that ACP pretreatment consistently improved EO extraction compared to seeds that hadn’t been treated. The most significant increase – a 44% boost – was achieved using argon gas. Scanning electron microscopy, a technique that provides highly magnified images of surfaces, revealed why. The ACP treatment created tiny cracks and fissures on the seed surface, effectively making it easier for the EO to be released during extraction. Interestingly, argon caused more color change and browning than air, but also yielded the highest extraction rates. This finding builds on previous research demonstrating the potential of plasma technology in food processing. For example, studies have shown that ACP can effectively eliminate harmful bacteria on fresh produce[2]. While that research focused on decontamination, this study explores a different application: enhancing the yield of valuable compounds. The researchers also analyzed the chemical composition of the extracted EO. They found that the ACP treatment, particularly with argon, increased the concentration of cumin aldehyde – the compound largely responsible for cumin’s characteristic flavor and aroma. This is significant because a higher concentration of key compounds translates to a more potent and valuable EO. The observed increase in extraction efficiency aligns with earlier findings regarding the benefits of physical treatments on plant materials. For instance, low-pressure plasma treatment of brown rice was shown to increase α-amylase activity, leading to improved germination and nutrient availability[3]. While the mechanisms differ, both studies demonstrate how altering the physical structure of plant material can unlock greater access to valuable compounds. Furthermore, the antimicrobial and antioxidant properties of cumin have been well-documented[4]. The essential oil has shown activity against common bacteria like E. coli and S. aureus, and possesses significant antioxidant capacity. By improving EO extraction, this ACP technique could potentially make these beneficial compounds more readily available for use in food preservation or nutritional supplements. The study suggests that ACP could be a viable alternative to traditional, and often expensive, EO extraction methods.

BiotechBiochemSpices

References

Main Study

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

Published 24th January, 2024

https://doi.org/10.1002/jsfa.13290

Related Studies

2) High voltage atmospheric cold air plasma control of bacterial biofilms on fresh produce.

https://doi.org/10.1016/j.ijfoodmicro.2019.01.005

3) An improved process for high nutrition of germinated brown rice production: Low-pressure plasma.

https://doi.org/10.1016/j.foodchem.2015.01.083

4) Antimicrobial property, antioxidant capacity, and cytotoxicity of essential oil from cumin produced in Iran.

https://doi.org/10.1111/j.1750-3841.2009.01467.x


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