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Estimation of total soluble solids in grape berries using a hand‐held NIR spectrometer under field conditions
Author(s) -
Urraca Ruben,
SanzGarcia Andres,
Tardaguila Javier,
Diago Maria P
Publication year - 2016
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7470
Subject(s) - berry , brix , calibration , ripeness , chemistry , near infrared spectroscopy , analyser , food science , mathematics , horticulture , chromatography , statistics , biology , sugar , ripening , neuroscience
BACKGROUND Recent studies have reported the potential of near infrared ( NIR ) spectral analysers for monitoring the ripeness of grape berries as an alternative to wet chemistry methods. This study covers various aspects regarding the calibration and implementation of predictive models of total soluble solids ( TSS ) in grape berries using laboratory and in‐field collected NIR spectra. RESULTS The performance of the calibration models obtained under laboratory conditions indicated that at least 700 berry samples are required to assure enough prediction accuracy. A statistically significant error reduction ( ΔRMSECV = 0.1°Brix) with P < 0.001 was observed when measuring berries without epicuticular wax, which was negligible from a practical point of view. Under field conditions, the prediction errors ( RMSEP = 1.68°Brix, and SEP = 1.67°Brix) were close to those obtained with the laboratory dataset ( RMSEP = 1.42°Brix, SEP = 1.40°Brix). CONCLUSION This work clarifies several methodological factors to develop a protocol for in‐field assessing TSS in grape berries using an affordable, non‐invasive, portable NIR spectral analyser. © 2015 Society of Chemical Industry