Discrimination of Robusta Amazonico coffee farmed by indigenous and non-indigenous people in Amazon: comparing benchtop and portable NIR using ComDim and duplex

Author(s)

Baqueta, Michel Rocha ; Valderrama, Patricia ; Alves, Enrique Anastacio ; Pallone, Juliana Azevedo Lima ; Marini, Federico

• Document type: Journal article
• Source: ANALYST; v. 148, n. 7, p. 10-pg., 2023-02-28.

Abstract

Robusta Amazonico is the name given to the Amazonian coffee that has been becoming popular and has recently been registered as a geographical indication in Brazil. It is produced by indigenous and non-indigenous coffee producers in regions that are geographically very close to one another. There is a need to authenticate whether coffee is truly produced by indigenous people and near-infrared (NIR) spectroscopy is an excellent technique for this. To meet the substantial trend towards NIR spectroscopy miniaturization, this work compared benchtop and portable NIR instruments to discriminate Robusta Amazonico samples using partial least squares discriminant analysis (PLS-DA). To ensure the results to be fairly comparable and, at the same time, to guarantee representative selection of both training and test set for the discriminant analysis, a sample selection strategy based on coupling ComDim multi-block analysis and the duplex algorithm was applied. Different pre-processing techniques were tested to create multiple matrices to be used in ComDim, as well as to build the discriminant models. The best PLS-DA model for benchtop NIR provided an accuracy of 96% for the test samples, while for the portable NIR the correct classification rate was 92%. It was demonstrated that portable NIR provides similar results to benchtop NIR for coffee origin classification by performing an unbiased sample selection strategy. (AU)

• FAPESP's process: 19/21062-0 - Chemical descriptors and emerging green technologies combined with chemometrics for characterization and evaluation of Brazilian specialty coffees
• Grantee: Michel Rocha Baqueta
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 22/03268-3 - Alternative analytical techniques and in vitro digestion assays to special foods
• Grantee: Juliana Azevedo Lima Pallone
• Support Opportunities: Regular Research Grants
• FAPESP's process: 22/04068-8 - Innovative chemometrics-based analytical approaches for the multiplatform evaluation of Brazilian Canephora coffees with geographical indication
• Grantee: Michel Rocha Baqueta
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate