Laboratório de Petroleômica e Forense, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferrari, 514, Goiabeiras, Vitória, ES CEP: 29075-910, Brazil.
ASTRO34 Advanced Scientific Technologies, São Paulo, SP, Brazil.
Talanta. 2018 Jan 1;176:59-68. doi: 10.1016/j.talanta.2017.08.009. Epub 2017 Aug 3.
The use of portable micro-spectrometers such as a micro near infrared region (microNIR) spectrometer is a promising technique for solving analytical problems in several areas of science. This work evaluated the potential of microNIR in quality control of Arabica coffee. Arabica coffee has a high commercial value product, motivating the development of analytical methods with high sensitivity and accuracy for detection of its adulteration. Herein, microNIR was successfully used to determine the quality of Arabica coffee by identification and quantification of adulterations such as Robusta coffee (in different roasting levels), as well as corn, peels, and sticks. MicroNIR was combined with multivariate calibration by partial least squares (PLS) and principal component analysis (PCA). A total of 125 blends were produced, containing thirteen different concentrations of the adulterants (corn and peels/sticks, and the Robusta coffee) ranging from 1 to 100wt%. Developed PCA and PLS models were also applied to monitor the quality of sixteen commercial coffee samples. The results obtained using microNIR proved the ability of the method to be efficient and capable in the prediction of adulterations with minimum quantification levels (LOQs of 5-8wt%), being able to be applied to quality control of commercial coffee samples. Therefore, microNIR can reduce and simplify the time of analysis and sample preparation step, as well as to guarantee the efficiency of real-time data acquisition owing to its portability.
便携式微型分光光度计（如微型近红外光谱仪）的使用是解决科学多个领域分析问题的一种很有前途的技术。本工作评估了微型近红外光谱仪在阿拉比卡咖啡质量控制中的应用潜力。阿拉比卡咖啡是一种具有高商业价值的产品，这促使人们开发出具有高灵敏度和准确性的分析方法，以检测其掺假情况。本文成功地使用微型近红外光谱仪通过鉴定和定量掺杂物（如不同烘焙程度的罗布斯塔咖啡）以及玉米、果皮和枝条来确定阿拉比卡咖啡的质量。微型近红外光谱仪与偏最小二乘（PLS）和主成分分析（PCA）相结合进行多元校正。共制作了 125 种混合物，包含 13 种不同浓度的掺杂物（玉米和果皮/枝条以及罗布斯塔咖啡），浓度范围为 1 至 100wt%。开发的 PCA 和 PLS 模型也应用于监测 16 个商业咖啡样品的质量。使用微型近红外光谱仪获得的结果证明了该方法在预测掺假物方面的高效性和能力，最低定量水平（LOQ 为 5-8wt%），能够应用于商业咖啡样品的质量控制。因此，微型近红外光谱仪可以减少和简化分析和样品制备步骤的时间，并保证由于其便携性而实现实时数据采集的效率。
