Złotek Urszula, Karaś Monika, Gawlik-Dziki Urszula, Szymanowska Urszula, Baraniak Barbara, Jakubczyk Anna
Department of Biochemistry and Food Chemistry, University of Life Sciences in Lublin, Poland.
Acta Sci Pol Technol Aliment. 2016 Jul-Sep;15(3):281-288. doi: 10.17306/J.AFS.2016.3.27.
Coffee is important source of natural antioxidants in the diet, such as phenolic compounds, alkaloids, mainly caffeine, diterpenes (cafestol and kahweol) and Maillard reaction products formed during roasting.
In aqueous and methanolic extracts of coffee (Coffea arabica L.) roasted using traditional techniques from Brazil (B), Colombia (C), Ethiopia (E), Kenya (K) and coffee roasted using an industrial technique from Brazil (T), the phenolic and caffeine content as well as antioxidant properties were determined.
Comparing the results from water and methanolic extracts it should be noted that the highest amount of phenolics was determined for a methanolic extract of coffee roasted using the industrial technique (650.96 mg GAE/g DW) and a water extract of Kenya coffee (461.63 mg GAE/g DW). Caffeine content was on average two times higher in all methanolic extracts than in water extracts. The radical scavenging activity of aqueous extracts was found to be higher than methanolic extracts. The highest antioxidant scavenging activity was determined for C (EC50 = 1.16 mg DW/ml) and E (EC50 = 1.3 mg DW/ml) water extracts. Compared to water extracts methanolic extracts showed significantly higher reducing power, ability to chelate Fe2+, inhibition of linoleic acid peroxidation and inhibition of lipoxygenase.
This study demonstrated that the methanolic extracts obtained from different types of coffee exhibit potential anti-inflammatory and antioxidant properties. The highest antioxidant activity was shown by traditionally roasted coffees from Colombia and Ethiopia.
咖啡是饮食中天然抗氧化剂的重要来源，如酚类化合物、生物碱（主要是咖啡因）、二萜类化合物（咖啡醇和咖啡豆醇）以及烘焙过程中形成的美拉德反应产物。
测定了采用巴西（B）、哥伦比亚（C）、埃塞俄比亚（E）、肯尼亚（K）传统工艺烘焙的咖啡（阿拉比卡咖啡）水提取物和甲醇提取物以及采用巴西工业工艺烘焙的咖啡（T）中的酚类和咖啡因含量以及抗氧化性能。
比较水提取物和甲醇提取物的结果可知，采用工业工艺烘焙的咖啡甲醇提取物（650.96 mg GAE/g DW）和肯尼亚咖啡水提取物（461.63 mg GAE/g DW）中的酚类含量最高。所有甲醇提取物中的咖啡因含量平均是水提取物中的两倍。发现水提取物的自由基清除活性高于甲醇提取物。C（EC50 = 1.16 mg DW/ml）和E（EC50 = 1.3 mg DW/ml）水提取物的抗氧化清除活性最高。与水提取物相比，甲醇提取物的还原能力、螯合Fe2+的能力、抑制亚油酸过氧化的能力和抑制脂氧合酶的能力明显更高。
本研究表明，从不同类型咖啡中获得的甲醇提取物具有潜在的抗炎和抗氧化特性。哥伦比亚和埃塞俄比亚传统烘焙咖啡的抗氧化活性最高。
