Abstract

Cup tasting is the most important tool to access the quality of coffee beans. However, the use of sensory evaluation alone can present some problems, since bias from the previous knowledge of a particular sample and health conditions of the taster can influence the results. Given the well-established potential of spectroscopic methods in coffee quality evaluation, in the present study, we sought to evaluate the potential of FTIR spectroscopy for quantitative evaluation of specialty coffee quality. Samples of specialty coffee were provided by the Federação dos Cafeicultores do Cerrado Mineiro and Fazenda Barinas. They were roasted in IKAWA coffee roaster, analyzed by a group of Q-graders, and submitted to FTIR analysis. Physicochemical analyses (pH, titratable acidity, brix, total solids, and browning compounds) were also employed to show potential differences. Only pH showed significant difference between the beverages. PLS results showed consistent models for predicting the quality previously given by the cuppers, with low values of RMSEC and RMSEP (0.23 both). Also, the models showed high values of Rc (0.99) and Rv (0.97). The whole spectra were considered as important to classify the coffees by their quality, showing the complexity of the beverage.

中文翻译：

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FTIR和化学计量学是预测特种咖啡质量的有效工具

摘要

品尝杯是获取咖啡豆品质的最重要工具。但是，单独使用感官评估会带来一些问题，因为对特定样品的先前知识和品尝者的健康状况的偏见会影响结果。鉴于光谱学方法在咖啡质量评估中已确立的潜力，在本研究中，我们寻求评估FTIR光谱法对特种咖啡质量进行定量评估的潜力。Federaçãodos Cafeicultores do Cerrado Mineiro和Fazenda Barinas提供了特色咖啡样品。将它们在IKAWA咖啡烘焙机中烘焙，由一组Q级人员进行分析，然后进行FTIR分析。物理化学分析（pH，可滴定酸度，白利糖度，总固体，和褐变化合物）也用于显示电位差。饮料之间只有pH值显示出显着差异。PLS结果显示了一致的模型，可以预测先前由铜杯提供的质量，而RMSEC和RMSEP的值较低（均为0.23）。此外，模型显示出较高的Rc（0.99）和Rv（0.97）值。整个光谱被认为对按咖啡质量进行分类很重要，这表明饮料的复杂性。