ATR-MIR spectroscopy as a tool to assist 'Tempranillo' clonal selection process: Geographical origin and year of harvest discrimination and oenological parameters prediction

André Mendes Lemos; Nelson Machado; Marcos Egea-Cortines; Ana Isabel Barros

doi:10.1016/j.foodchem.2020.126938

ATR-MIR spectroscopy as a tool to assist 'Tempranillo' clonal selection process: Geographical origin and year of harvest discrimination and oenological parameters prediction

Food Chem. 2020 Apr 28:325:126938. doi: 10.1016/j.foodchem.2020.126938. Online ahead of print.

Authors

André Mendes Lemos¹, Nelson Machado², Marcos Egea-Cortines³, Ana Isabel Barros⁴

Affiliations

¹ Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro (CITAB-UTAD), 5000-801 Vila Real, Portugal. Electronic address: andre_mlemos@hotmail.com.
² Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro (CITAB-UTAD), 5000-801 Vila Real, Portugal; CoLAB Vines&Wines - National Collaborative Laboratory for the Portuguese Wine Sector, Associação para o Desenvolvimento da Viticultura Duriense (ADVID), Edifício Centro de Excelência da Vinha e do Vinho, Régia Douro Park, 5000-033 Vila Real, Portugal.
³ Genetica Molecular, Instituto de Biotecnología Vegetal, Universidad Politécnica de Cartagena, 30202 Cartagena, Spain.
⁴ Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro (CITAB-UTAD), 5000-801 Vila Real, Portugal.

PMID: 32387957
DOI: 10.1016/j.foodchem.2020.126938

Abstract

The present study evaluated the ability of Attenuated Total Reflectance - Mid-Infrared (ATR-MIR) spectroscopy combined with Partial Least Squares Discriminant Analysis (PLS-DA) to discriminate the origin and harvest year of 'Tempranillo' grape clones and with Partial Least Squares (PLS) regressions to predict its contents in soluble solids (SS), pH and titratable acidity (TA). Normalized spectra of grape homogenates and normalized plus 1st Derivative spectra of grape skins allowed an overall percentage of correct classifications of 99.6% and 96.7% in validation, according to origin, and 98.3% and 90.0% in validation, according to harvest year, respectively. The normalized spectra of grape homogenates allowed a calibration and validation determination coefficients (R²) of 0.92 and 0.90 for SS, 0.90 and 0.84 for pH, 0.88 and 0.84 for TA, respectively. The ATR-MIR combined with multivariate analysis showed to be an appropriate tool to assist the clonal selection process of 'Tempranillo'.

Keywords: ATR-MIR spectroscopy; Clones; Geographical origin discrimination; Oenological parameters prediction; Tempranillo.