Fathi Mehran, Hatamzadeh Abdullah, Ebadi Mohammad-Taghi, Ghomi Hamid
Department of Horticultural Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran.
Department of Horticultural Science, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
J Sci Food Agric. 2025 Aug 30;105(11):5766-5779. doi: 10.1002/jsfa.14286. Epub 2025 Jun 18.
Cold plasma (CP) was investigated as an innovative method to enhance green tea (Camellia sinensis) quality by improving extraction efficiency, bioactive retention. This study optimized dielectric barrier discharge (DBD) CP using air, argon, and nitrogen at 14, 18, and 22 kV for 6, 9, and 12 min to improve extraction and the qualitative and quantitative properties of green tea.
CP treatments significantly impacted green tea traits. Argon and air gases, especially at higher voltages (22 kV) and longer durations (12 min), significantly increased hydrophilicity and phytochemical extraction, increasing yields by up to 48% compared to the control. These treatments had the highest total phenol [78.334 and 77.08 mg g dry weight (DW)], total flavonoid (8.09 and 7.72 mg g DW), antioxidant activity (80.74% and 81.93%), and catechins compounds content. Color properties, including brightness (L*) and greenness (a*), were enhanced compared to the control, with argon > air > nitrogen in effectiveness. Some treatments reduced color indices with higher voltage/time, while others increased them. Air and argon plasma (22 kV, 12 min) enhanced brightness, yellow-green color, and color purity in brewed tea. Principal component analysis (PCA) biplot confirmed that argon (18 and 22 kV, 12 min) and air (22 kV, 12 min) improved hydrophilicity, total phenol content, total flavonoid content, antioxidant activity, catechins, and color quality.
While argon and air plasmas were effective for extracting important phytochemicals, successful large-scale commercialization must consider costs, ionization potential, and energy usage, and so forth, of plasmas based on argon versus air. These findings can benefit the tea processing industry in producing higher-quality products for various sectors. © 2025 Society of Chemical Industry.
冷等离子体（CP）作为一种创新方法，通过提高提取效率和生物活性保留来提升绿茶（茶树）品质。本研究优化了介质阻挡放电（DBD）冷等离子体，使用空气、氩气和氮气，在14、18和22千伏下处理6、9和12分钟，以改善绿茶的提取以及定性和定量特性。
冷等离子体处理显著影响绿茶特性。氩气和空气气体，特别是在较高电压（22千伏）和较长处理时间（12分钟）下，显著提高了亲水性和植物化学物质提取率，与对照相比产量提高了48%。这些处理具有最高的总酚含量[78.334和77.08毫克/克干重（DW）]、总黄酮含量（8.09和7.72毫克/克DW）、抗氧化活性（80.74%和81.93%）以及儿茶素化合物含量。与对照相比，颜色特性，包括亮度（L*）和绿色度（a*）得到增强，氩气>空气>氮气的效果依次递减。一些处理随着电压/时间升高降低了颜色指数，而另一些则提高了颜色指数。空气和氩气等离子体（22千伏，12分钟）增强了冲泡茶的亮度、黄绿色度和颜色纯度。主成分分析（PCA）双标图证实，氩气（18和22千伏，12分钟）和空气（22千伏，12分钟）改善了亲水性、总酚含量、总黄酮含量、抗氧化活性、儿茶素和颜色质量。
虽然氩气和空气等离子体对提取重要的植物化学物质有效，但成功的大规模商业化必须考虑基于氩气与空气的等离子体的成本、电离电位和能源使用等因素。这些发现可为茶叶加工业生产面向不同领域的更高质量产品带来益处。© 2025化学工业协会。
