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.
Highlights
Today, fresh food intake is becoming an even greater matter of health and well-being, rather than solely a concern of personal predilections or taste, due to the presence, especially in fruits, of several bioactive compounds, including carotenoids, flavonoids, phenolic compounds, and vitamins [1].Watermelon (Citrullus lanatus) is a member of the Cucurbitaceae family of gourds and is related to the cucumber, squash, and pumpkin [2]
The results of this study have been applied to the market valorization of the analyzed watermelons; each of them has been commercialized for its unique lycopene, β-carotene, and total soluble solid (TSS) content, immediately visible to consumers through a label on the fruit skin
Baseline offset of the spectra collected in 2014 could be due to the effect of movement at different speed rates, whilst in 2013 spectra were collected in stationary mode
Summary
Fresh food intake is becoming an even greater matter of health and well-being, rather than solely a concern of personal predilections or taste, due to the presence, especially in fruits, of several bioactive compounds, including carotenoids, flavonoids, phenolic compounds, and vitamins [1]. The majority of them are based on colorimetric or chromatographic assays after organic solvent extraction [20] These methods are destructive, laborious, and time-consuming, requiring the preparation of samples with hazardous and expensive reagents. The NIRS method has been successfully developed for non-destructive analysis of internal watermelon quality, such as sugar content [33] and total soluble solid (TSS) content [34]. We describe in this paper the development of an NIRS in-line application in the post-harvesting stage as a direct and non-destructive method to determine lycopene and β-carotene content in single intact fruits, while simultaneously estimating the Brix degree. The results of this study have been applied to the market valorization of the analyzed watermelons; each of them has been commercialized for its unique lycopene, β-carotene, and TSS content, immediately visible to consumers through a label on the fruit skin
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
