Confirmation of Declared Provenance of European Extra Virgin Olive Oil Samples by NIR Spectroscopy

Abstract

The potential of near-infrared transflectance spectroscopy (1100-2498 nm) combined with chemometric techniques to confirm the geographical origin of European olive oil samples was evaluated. In total, 913 extra virgin olive oil samples (210 Ligurian and 703 non-Ligurian) were collected over three consecutive harvests (2005, 2006, and 2007). A multivariate spectral fingerprint for Ligurian olive oil was developed and deployed to confirm or refute a claim that any given sample was Ligurian. Samples were pseudorandomly split into calibration (n = 280) and validation sets (n = 633); the only selection constraint applied was to insist on equal numbers of Ligurian and non-Ligurian samples in the calibration set. Following preliminary examination by principal component analysis, the full spectrum modeling method applied to the spectral data set was discriminant partial least-squares regression; various data pretreatments were also investigated. The best models correctly predicted the origins of samples in the prediction set up to 92.8 and 81.5% for Ligurian and non-Ligurian olive oil samples, respectively, using a first-derivative data pretreatment. The potential of this approach in commercial traceability and quality assurance schemes is noted.

High resolution NMR characterization of olive oils in terms of quality, authenticity and geographical origin

“…Metabolic fingerprinting approach has been employed for olive oil studies by FTIR, [31,32] NIR, [33][34][35] Raman [36] and NMR [37][38][39] techniques. Among the various analytical techniques used to analyze olive oils, NMR spectroscopy has gained an important role in olive oil characterization.…”

Identifying camellia oil adulteration with selected vegetable oils by characteristic near-infrared spectral regions

“…11 Based on previous studies, band 1 ranging from 1111 nm to 1265 nm is related to the second overtone of C-H stretching vibrations of methyl and methylene groups; band 2 ranging from 1342 nm to 1492 nm is related to the C-H stretching vibrations; band 3 ranging from 1639 nm to 1887 nm is associated with the¯rst over tone of CH 2 stretching vibrations of methyl and methylene groups; and band 4 locating between 2083 nm and 2222 nm is associated with C-H stretching vibration with other vibrational modes. 26 For di®erent samples, the entire spectra looked closely similar both on the spectral pattern and the absorbance values. Chemometrics methods were utilized to highlight the small discrepancies of chemical composition between pure camellia oil and those adulterated with other cheaper vegetable oils.…”

A Review of Optical Nondestructive Visual and Near-Infrared Methods for Food Quality and Safety

“…Woodcock et al [109] studied European olive oil samples to specify their geographical origins with near-infrared transflectance spectroscopy (1100-2498 nm). The samples were collected from harvests of 2005, 2006, and 2007.…”