Identification of adulteration in ground roasted coffees using UV-Vis spectroscopy and SPA-LDA

- Coffee adulteration by husks and sticks under study.
- Extracts of ground roasted coffees prepared in hot water alone were analyzed.
- UV-Vis spectra were used as analytical information.
- Evaluations using SIMCA, PLS-DA and SPA-LDA.
- A 100% classification was obtained with SPA-LDA variable selection.

The pleasant taste and flavor of coffee are responsible for making it one of the most preferred and consumed beverages around the world. Industrial coffee plants usually roast both coffee and adulterants together, which affects directly the quality of the product, specially the sensorial characteristics of the drink. Therefore, this work aims the identification of adulterations in ground roasted coffees (due to the presence of husks and sticks) using ultraviolet-visible spectroscopy and the Successive Projections Algorithm for variable selection in association with Linear Discriminant Analysis (SPA-LDA). For this purpose, extracts of ground roasted coffees prepared in hot water alone (representing the final product as ingested by the consumers) were then analyzed. The proposed methodology obtained a 100% classification in both training and test sets, providing a simple and fast analysis of the aqueous extracts of ground roasted coffees. Moreover, it can also afford security to coffee consumers and regulatory agencies, preventing the fraudulent labeling.