Division of Product Development Technology, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai 50100, Thailand.
Department of Industrial Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand.
Molecules. 2023 Oct 13;28(20):7066. doi: 10.3390/molecules28207066.
Cold plasma technology is gaining attention as a promising approach to enhancing the bioactivity of plant extracts. However, its impact on green coffee bean extracts (GCBEs) still needs to be explored. In this study, an innovative underwater plasma jet system was employed to investigate the effects of cold plasma on GCBEs, focusing on the conjugation reflected by the change in composition and bioactivity. The DPPH radical scavenging antioxidant activity exhibited a gradual increase with plasma treatment up to 35 min, followed by a decline. Remarkably, at 35 min, the plasma treatment resulted in a significant 66% increase in the DPPH radical scavenging activity of the GCBE. The total phenolic compound content also displayed a similar increasing trend to the DPPH radical scavenging activity. However, the phenolic profile analysis indicated a significant decrease in chlorogenic acids and caffeine. Furthermore, the chemical composition analysis revealed a decrease in free amino acids, while sucrose remained unchanged. Additionally, the SDS-PAGE results suggested a slight increase in protein size. The observed enhancement in antioxidant activity, despite the reduction in the two major antioxidants in the GCBE, along with the increase in protein size, might suggest the occurrence of conjugation processes induced by plasma, particularly involving proteins and phenolic compounds. Notably, the plasma treatment exhibited no adverse effects on the extract's safety, as confirmed by the MTT assay. These findings indicate that cold plasma treatment holds significant promise in improving the functional properties of GCBE while ensuring its safety. Incorporating cold plasma technology into the processing of natural extracts may offer exciting opportunities for developing novel and potent antioxidant-rich products.
冷等离子体技术作为一种提高植物提取物生物活性的有前途的方法引起了人们的关注。然而，其对绿咖啡豆提取物（GCBE）的影响仍需探索。在这项研究中，采用了一种创新的水下等离子体射流系统来研究冷等离子体对 GCBE 的影响，重点关注成分和生物活性变化所反映的共轭作用。DPPH 自由基清除抗氧化活性随着等离子体处理时间的增加逐渐增加，达到 35 分钟后下降。值得注意的是，在 35 分钟时，等离子体处理使 GCBE 的 DPPH 自由基清除活性显著增加了 66%。总酚含量也呈现出与 DPPH 自由基清除活性相似的增加趋势。然而，酚类分析表明绿原酸和咖啡因的含量显著下降。此外，化学成分分析表明游离氨基酸减少，而蔗糖保持不变。此外，SDS-PAGE 结果表明蛋白质大小略有增加。尽管 GCBE 中两种主要抗氧化剂减少，但抗氧化活性增强，以及蛋白质大小增加，这可能表明等离子体诱导的共轭过程发生，特别是涉及蛋白质和酚类化合物。值得注意的是，MTT 测定证实，等离子体处理对提取物的安全性没有不良影响。这些发现表明，冷等离子体处理在提高 GCBE 的功能特性的同时确保其安全性方面具有重要意义。将冷等离子体技术纳入天然提取物的加工中可能为开发新型、强效富含抗氧化剂的产品提供令人兴奋的机会。
