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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Functional Foods Research » Research » Publications at this Location » Publication #321578

Research Project: Improving Quality, Stability, and Functionality of Oils and Bioactive Lipids

Location: Functional Foods Research

Title: Detection of corn adulteration in Brazilian coffee (Coffea arabica) by tocopherol profiling and near-infrared (NIR) spectroscopy

Author
item Moser, Jill
item Singh, Mukti
item Rennick, Kathy
item Bakota, Erica
item Jham, Gulab - Universidade Federal De Viçosa
item Liu, Sean
item Vaughn, Steven

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/18/2015
Publication Date: 11/24/2015
Citation: Winkler-Moser, J.K., Singh, M., Rennick, K.A., Bakota, E.L., Jham, G., Liu, S.X., Vaughn, S.F. 2016. Detection of corn adulteration in Brazilian coffee (Coffea arabica) by tocopherol profiling and near-infrared (NIR) spectroscopy. Journal of Agricultural and Food Chemistry. 63(49):10662-10668.

Interpretive Summary: Coffee is a high-value commodity that is a target for adulteration by low value materials, such as corn, wheat, soybeans, husks, and lower-grade coffee. This leads to loss of quality and can potentially be a safety hazard if allergens are introduced. Therefore, there is significant interest in developing methods for detecting coffee adulteration and improving the sensitivity and accuracy of these methods. In this study, we used tocopherol profile and near-infrared spectroscopy for detection of coffee adulteration with corn. Pure Brazilian roasted, ground coffee bean samples were adulterated with 1% to 20% of roasted, ground corn and were analyzed for their tocopherol content by HPLC, and by Near Infrared Spectroscopy. Both proposed methods of detection of corn adulteration displayed a sensitivity of around 5%, thus representing simple and fast analytical methods for detecting adulteration at likely levels of contamination. Coffee growers and consumers will benefit from new methods for detecting adulteration of coffee and other high value commodities, ensuring high quality and safety of products.

Technical Abstract: Coffee is a high-value commodity that is a target for adulteration, especially after the beans have been roasted and ground. Countries such as Brazil, the second largest coffee producer, have set limits on the allowable amount of coffee contamination and adulteration. Therefore, there is significant interest in developing methods for detecting coffee adulteration and improving the sensitivity and accuracy of these methods. Corn and other lower-valued crops are potential adulterants, along with sticks and coffee husks. Fourteen pure Brazilian roasted and ground coffee bean samples were adulterated with 1% to 20% of roasted and ground corn and were analyzed for their tocopherol content and composition by HPLC, and were also analyzed by near-infrared (NIR) spectroscopy. Both proposed methods of detection of corn adulteration displayed a sensitivity of around 5%, thus representing simple and fast analytical methods for detecting adulteration at likely levels of contamination.