Portable near infrared spectroscopy applied to quality control of Brazilian coffee

Abstract

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.

Handheld Near‐Infrared Spectroscopy for Distinction of Extra Virgin Olive Oil from Other Olive Oil Grades Substantiated by Compositional Data

“…A handheld NIR Pro 1700ES spectrometer (JDSU, Milpitas, CA, USA), palm‐sized (45 × 42 mm), weighing 60 g, and with a working wavelength range of 908–1676 nm, was applied. The spectrometer employs a linear variable filter as the light dispersing element which results in high signal‐to‐noise ratio . The absorption spectra of the olive oil samples were acquired at room temperature (21 ± 1 °C).…”

Nitrogen Demand Associated with Increased Biomass Yield of Switchgrass and Big Bluestem: Implications for Future Breeding Strategies

“…The latter would be advantageous because of the time and labor commitment required for harvesting biomass plots. Hand-held or portable NIRS units are capable of predicting chemical constituents of liquids, fruits, grains, and herbage [41][42][43][44][45][46]. Similar technologies have been used to scan forage-crop canopies to predict N concentration of standing alfalfa (Medicago sativa L.) or bermudagrass (Cynodon dactylon (L.) Pers.)…”

Insight into Rapid DNA-Specific Identification of Animal Origin Based on FTIR Analysis: A Case Study

“…The FTIR spectral data in the region (1800−800 cm −1 ) was analyzed using the Matlab version R2015 (Mathworks, Natick, MA, USA). Multiplicative scattering correction (MSC) was used prior to the multivariate analysis, including PCA and PLS-DA [ 40 , 41 , 42 ]. Preprocessing and multivariate analysis were performed with the PLS Toolbox 8.0 (Eigenvector Research, Wenatchee, WA, USA).…”