ABSTRACT Mexico is one of the world leaders in the production of coffee, but research on bioactive compounds and antioxidant activity in Mexican coffee has been extremely limited and, importantly, the effect of organic farming on these properties has not been widely studied. Spent coffee grounds (SCG), the main by-product of coffee brewing, represent a serious environmental problem, but could become an important source of bioactive compounds for the pharmaceutical and food-processing industry. The aim of this work was, therefore, to study the effect of organic farming on bioactive and antioxidant properties of SCG; comparing samples of organic and conventionally grown coffee from the Mexican states of Veracruz and Chiapas, both of which produce coffee with the ‘Protected Designation of Origin’ distinction. Concentrations of total phenolic compound and total flavonoid compounds, DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis-3-ethylbenzthiazoline 6- sulphonic-acid) antioxidant activity, and brown compound concentration were determined in SCG. Repeated measures ANOVAs were carried out on the data. Organic SCG samples showed significantly higher bioactive compound concentration (p < 0.01) and antioxidant activity (p < 0.001) than conventional SCG samples. This difference held across various extractions and the two geographical locations. Thus, this Mexican organic coffee by-product may represent an interesting source of such compounds for diverse industrial applications. Given that Mexico is one of the top producers of organic coffee in the world, there is a need for further research to consider other important variables, such as the type of coffee processing by-product and the type of coffee extraction process.

中文翻译：

---

有机农业对墨西哥废咖啡渣总酚、总黄酮、棕色化合物和抗氧化活性的影响

摘要 墨西哥是咖啡生产的世界领先者之一，但对墨西哥咖啡生物活性化合物和抗氧化活性的研究极其有限，重要的是，有机农业对这些特性的影响尚未得到广泛研究。废咖啡渣 (SCG) 是咖啡酿造的主要副产品，代表着严重的环境问题，但可能成为制药和食品加工行业生物活性化合物的重要来源。因此，这项工作的目的是研究有机农业对 SCG 生物活性和抗氧化特性的影响；比较来自墨西哥韦拉克鲁斯州和恰帕斯州的有机和传统种植咖啡的样品，这两个州都生产具有“受保护原产地名称”区别的咖啡。总酚类化合物和总黄酮类化合物、DPPH（2,2-diphenyl-1-picrylhydrazyl）和 ABTS（2,2'-azino-bis-3-ethylbenzthiazoline 6-sulfonic-acid）抗氧化活性的浓度，以及棕色化合物浓度在 SCG 中确定。对数据进行重复测量方差分析。有机 SCG 样品显示出比传统 SCG 样品显着更高的生物活性化合物浓度 (p < 0.01) 和抗氧化活性 (p < 0.001)。这种差异存在于各种提取物和两个地理位置。因此，这种墨西哥有机咖啡副产品可能代表了用于各种工业应用的此类化合物的有趣来源。鉴于墨西哥是世界上最大的有机咖啡生产国之一，需要进一步研究以考虑其他重要变量，