title: Quantification of Lycopene, β-Carotene, and Total Soluble Solids in Intact Red-Flesh Watermelon (Citrullus lanatus) Using On-Line Near-Infrared Spectroscopy.
abstract: A great interest has recently been focused on lycopene and β-carotene, because of their antioxidant action in the organism. Red-flesh watermelon is one of the main sources of lycopene as the most abundant carotenoid. The use of near-infrared spectroscopy (NIRS) in post-harvesting has permitted us to rapidly quantify lycopene, β-carotene, and total soluble solids (TSS) on single intact fruits. Watermelons, harvested in 2013-2015, were submitted to near-infrared (NIR) radiation while being transported along a conveyor belt system, stationary and in movement, and at different positions on the belt. Eight hundred spectra from 100 samples were collected as calibration set in the 900-1700 nm interval. Calibration models were performed using partial least squares (PLS) regression on pre-treated spectra (derivatives and SNV) in the ranges 2.65-151.75 mg/kg (lycopene), 0.19-9.39 mg/kg (β-carotene), and 5.3%-13.7% (TSS). External validation was carried out with 35 new samples and on 35 spectra. The PLS models for intact watermelon could predict lycopene with R² = 0.877 and SECV = 15.68 mg/kg, β-carotene with R² = 0.822 and SECV = 0.81 mg/kg, and TSS with R² = 0.836 and SECV = 0.8%. External validation has confirmed predictive ability with R² = 0.805 and RMSEP = 16.19 mg/kg for lycopene, R2 = 0.737 and RMSEP = 0.96 mg/kg for β-carotene, and R² = 0.707 and RMSEP = 1.4% for TSS. The results allow for the market valorization of fruits.
authors.affiliation: Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara 44121, Italy. tme@unife.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Tamburini
authors.affiliation: Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara 44121, Italy. stefania.costa@unife.it.
authors.forename: Stefania
authors.initials: S
authors.lastname: Costa
authors.affiliation: Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara 44121, Italy. irene.rugiero@unife.it.
authors.forename: Irene
authors.initials: I
authors.lastname: Rugiero
authors.affiliation: Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara 44121, Italy. pdp@unife.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Pedrini
authors.affiliation: Department of Life Science and Biotechnology, University of Ferrara, Via L. Borsari 46, Ferrara 44121, Italy. mhm@unife.it.
authors.forename: Maria Gabriella
authors.initials: MG
authors.lastname: Marchetti
mesh_terms: D002338:Carotenoids; D029773:Citrullus; D000077276:Lycopene; D019265:Spectroscopy, Near-Infrared; D019207:beta Carotene
chemical_list: D019207:beta Carotene; D002338:Carotenoids; D000077276:Lycopene
keywords: Near Infrared Spectroscopy; carotenoids; lycopene; total soluble solid (TSS); watermelon; β-carotene