INTRODUCTION The consumption of high quality coffee such as specialty Arabica and fine Robusta coffee is increasing steadily in recent years. Development of single origin coffee is an important strategy to maintain coffee quality, grade and high cupping score. Indonesia is a top exporting country for Arabica coffee with high variety of specialty coffees from different origins. Despite its long standing reputation in global coffee market, very few is known about the variability among Indonesian specialty coffees. OBJECTIVES This study aims to observe metabolite variability among Indonesian coffees from different species and geographical origins by means of non-targeted GC/MS metabolite profiling. METHODS Sixty-four compounds were tentatively identified from 16 green and roasted coffee beans from different species and cultivation areas in Indonesia and were subjected to principal component analysis (PCA). Ten Specialty Arabica coffee and five Fine Robusta representing all important high quality coffees of Indonesia were also analyzed independently to further classify Indonesian coffee according to their origin. RESULTS PCA results of 16 green and roasted coffee beans of different species and cultivation areas showed that samples were separated along PC1 based on different roasting condition (green and roasted) with 52.9% variance and were separated along PC2 based on different species with 19.3% variance. The result from this study showed the clustering of samples based on three major cultivation areas in Indonesia (western, central, eastern part). Metabolites showing higher concentration in Sulawesi, Papua, Flores and Sumatra samples were glycerol, glucuno-1,5-lactone, gluconic acid and sorbitol. A clear distinction in galactitol and galactinol concentration between all samples from eastern part of Indonesia and western and middle part of Indonesia was also observed. CONCLUSIONS Our results showed that each region (western, central and eastern part of Indonesia) has signature compounds that may serve as discriminant markers for coffee authentication. This is the first report on the classification of Indonesian specialty coffee based on their metabolic profiles and can act as a basis for marker identification for routine procedures in industry.

中文翻译：

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基于GC / MS的印度尼西亚不同种类和地理来源的特种咖啡的代谢物谱分析。

简介近年来，高品质咖啡（如特色阿拉比卡咖啡和罗布斯塔咖啡）的消费量一直在稳定增长。单一来源咖啡的开发是保持咖啡质量，等级和高拔罐得分的重要策略。印度尼西亚是阿拉比卡咖啡的最大出口国，其咖啡豆来自不同的地方，种类繁多。尽管在全球咖啡市场上享有悠久的声誉，但对于印尼特色咖啡之间的差异知之甚少。目的本研究旨在通过非目标GC / MS代谢物谱分析来观察来自不同物种和地理来源的印尼咖啡之间的代谢物变异性。方法从印度尼西亚不同物种和种植地区的16种生咖啡豆和烘焙咖啡豆中初步鉴定出64种化合物，并对其进行主成分分析（PCA）。还分别分析了代表印度尼西亚所有重要优质咖啡的十种阿拉比卡咖啡和五种罗布斯塔咖啡，以根据其来源对印度尼西亚咖啡进行进一步分类。结果对16种不同品种和种植地区的生咖啡豆和焙炒咖啡豆的PCA结果表明，根据不同的焙烧条件（绿色和焙炒），沿PC1进行了样品分离，方差为52.9％；基于不同种类的PC2，进行了样品分离，方差为19.3％ 。这项研究的结果表明，样本的聚集是基于印度尼西亚的三个主要种植区（西部，中部，东部）。在苏拉威西，巴布亚，弗洛雷斯和苏门答腊样品中显示较高浓度的代谢产物为甘油，-1,5-内酯，5-内酯，葡萄糖酸和山梨醇。还观察到来自印度尼西亚东部和印度尼西亚西部和中部的所有样品之间的半乳糖醇和半乳糖醇浓度有明显的区别。结论我们的结果表明，每个地区（印度尼西亚的西部，中部和东部）都有签名化合物，可以用作咖啡认证的判别标记。这是根据印尼特色咖啡的代谢特征分类的第一份报告，可作为工业常规程序标记识别的基础。葡萄糖酸和山梨糖醇。还观察到来自印度尼西亚东部和印度尼西亚西部和中部的所有样品之间的半乳糖醇和半乳糖醇浓度有明显的区别。结论我们的结果表明，每个地区（印度尼西亚的西部，中部和东部）都有签名化合物，可以用作咖啡认证的判别标记。这是根据印尼特色咖啡的代谢特征分类的第一份报告，可作为工业常规程序标记识别的基础。葡萄糖酸和山梨糖醇。还观察到来自印度尼西亚东部和印度尼西亚西部和中部的所有样品之间的半乳糖醇和半乳糖醇浓度有明显的区别。结论我们的结果表明，每个地区（印度尼西亚的西部，中部和东部）都有签名化合物，可以用作咖啡认证的判别标记。这是根据印尼特色咖啡的代谢特征分类的第一份报告，可作为工业常规程序标记识别的基础。印尼中部和东部）有签名化合物，可以用作咖啡认证的判别标记。这是根据印尼特色咖啡的代谢特征分类的第一份报告，可作为工业常规程序标记识别的基础。印尼中部和东部）有签名化合物，可以用作咖啡认证的判别标记。这是根据印尼特色咖啡的代谢特征分类的第一份报告，可作为工业常规程序标记识别的基础。