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.

Enhancement of polyphenolic content extraction rate with maximal antioxidant activity from green tea leaves by cold plasma.

A dielectric barrier discharge (DBD) atmospheric cold plasma was evaluated as a tool to increase the extraction rate of total phenolic content (TPC) and antioxidant activity from green tea leaves. The effects of nitrogen DBD cold plasma on changes of color and surface morphology were investigated. Optimum conditions of cold plasma treatment (treatment time and generation power) were obtained by response surface methodology. After the nitrogen DBD cold plasma at 15 W of the generation power for 15 min, the TPC and antioxidant activity of green tea increased by 41.14% and 41.06%, respectively. The catechin also increased by 103.12%. The scanning electron microscopy results showed cell ablation and ruptures of the green tea leaf surface after nitrogen DBD cold plasma treatment. PRACTICAL APPLICATION: The developed DBD cold plasma source fed by nitrogen gas can be a suitable procedure for green and useful extraction of phenolic compounds from natural sources in the food industries.

The effect of cold atmospheric plasma on diabetes-induced enzyme glycation, oxidative stress, and inflammation; in vitro and in vivo.

Cold atmospheric plasma (CAP) is known as the versatile tool in different biological, and medical applications. In this study, we investigated the effect of cold plasma on diabetes via in vitro and in vivo assessments. We performed the in vitro assay to evaluate the impact of CAP on glycated glutathione peroxidase (GPx) through enzyme activity measurement as a function index and far- and near-UV circular dichroism (CD) and fluorescence analysis as structure indices. The result of in vitro assessment showed that the exposure of glycated GPx to plasma causes a considerable increase in enzyme activity up to 30%. Also, the evaluation of far- and near-UV CD and fluorescence analysis indicated a modification in the protein structure. According to obtained result from in vitro assessment, in vivo assay evaluated the effect of CAP on diabetic mice through analyzing of blood glucose level (BGL), advanced glycation end products (AGEs), antioxidant activity, oxidative stress biomarkers such as malondialdehyde (MDA), advanced oxidation protein products (AOPP), and oxidized low-density lipoprotein (oxLDL), and inflammation factors including tumor necrosis factor (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6). The result of in vivo experiment also showed a 20% increase in antioxidant activity. Also, the reduction in AGEs, oxidative stress biomarkers, and inflammatory cytokines concentrations was observed. The result of this study revealed that CAP could be useful in diabetes treatment and can be utilized as a complementary method for diabetes therapy.

Amelioration of Photosynthesis and Quality of Wheat under Non-thermal Radio Frequency Plasma Treatment.

Plasma treatment is recognized as a suitable technology to improve germination efficiency of numerous seeds. The objective of this paper is to demonstrate whether cold air plasma can change the quality and quantity of wheat yield. Effects of cold plasma treatment on wheat (Pishgam variety) yield were studied by a randomized complete block design experiment at the Faculty of Agriculture of Tarbiat Modarres University, Iran, during 2015-17. Seeds were pre-treated with 80 W of cold plasma at four levels of time, 60, 120, 180 and 240 seconds. Plasma effects on yield and quality of wheat were determined by measuring plant photosynthesis, grain yield, biological yield, 1000-grain weight, total chlorophyll, carotenoid, anthocyanin, protein and starch content. Results showed that plasma treatments had positive effects on wheat characteristics, and treatment of 180 s had the highest stimulatory effect. In both years, cold plasma increased grain yield at 180 s, but decreased it at 240 s compared with control. The rate of plant photosynthesis, grain yield, 1000-grain weight, carotenoid and anthocyanin were enhanced at 180 s. The starch content and grain protein were enhanced at 120 s cold plasma application compared with control.