做形与烘焙工艺对圆炒青绿茶抗氧化活性的影响

Effects of Shaping and Baking Processes on the Antioxidant Activity of Round Roasted Green Tea

摘要:

【目的】探究做形与烘焙工艺对圆炒青绿茶抗氧化活性的影响，为提升绿茶品质与优化加工技术提供理论支撑与实践参考。【方法】以圆炒青绿茶为对象，研究不同加工阶段及做形、烘焙等关键工序对其抗氧化活性的影响；采用斑马鱼模型（体内）以及DPPH自由基和ABTS⁺自由基清除率、铁离子还原能力（体外）等多指标综合评价其抗氧化性能。【结果】做形与烘焙条件对绿茶抗氧化活性具有显著影响。在不同烘焙温度下，做形温度的作用表现各异，例如在烘焙温度75 ℃、烘焙时间20 min、烘焙2次的条件下，90 ℃做形处理的DPPH自由基清除率显著高于120 ℃和150 ℃做形处理；而在做形温度90 ℃、做形时间50 min的条件下，105 ℃烘焙处理的铁离子还原能力显著优于75 ℃烘焙处理。通过工艺优化，确定最佳组合为做形温度90 ℃、做形时间50 min、烘焙温度90 ℃、烘焙时间20 min、烘焙2次，该工艺下绿茶DPPH自由基清除率较工厂常规工艺提升了43.54%。【结论】优化做形与烘焙工艺可显著增强圆炒青绿茶的抗氧化活性，为绿茶精细化加工与品质提升提供了科学支撑。

Abstract:

[Objective]This study investigated the effects of shaping and baking processes on the antioxidant activity of round roasted green tea, aiming to provide theoretical support and practical reference for improving the quality and optimizing the processing techniques of green tea.[Method]The influences of different processing stages and key procedures such as shaping and baking on the antioxidant activity of round roasted green tea were studied. A zebrafish model (in vivo) and multiple indexes including DPPH radical scavenging rate, ABTS? radical scavenging rate, and ferric ion reducing antioxidant power (FRAP) were employed for comprehensive evaluation of the antioxidant activity.[Result]Shaping and baking conditions significantly affected the antioxidant activity of green tea. The effect of shaping temperature varied under different baking temperatures. For example, under baking at 75 ℃ for 20 min (twice), the DPPH radical scavenging rate of green tea shaped at 90 ℃ was significantly higher than that at 120 ℃ and 150 ℃. In the case of shaping at 90 ℃ for 50 min, the FRAP of green tea baked at 105 ℃ was significantly better than that baked at 75 ℃. Through process optimization, the best combination was determined as shaping at 90 ℃ for 50 min + baking at 90 ℃ for 20 min (twice), under which the DPPH radical scavenging rate increased by 43.54% compared with that of conventional factory processes.[Conclusion]Optimizing shaping and baking processes can significantly enhance the antioxidant activity of round roasted green tea. This study provides scientific support for the refined processing and quality improvement of green tea.