Non-Destructive Detection of Pesticide-Treated Baby Leaf Lettuce During Production and Post-Harvest Storage Using Visible and Near-Infrared Spectroscopy

The market demand for baby leaf lettuce is constantly increasing, while safety has become one of the most important traits in determining consumer preference driven by human health hazards concerns. In this study, the performance of visible and near-infrared (vis/NIR) spectroscopy was tested in disc...

Full description

Saved in:
Bibliographic Details
Main Authors: Dimitrios S. Kasampalis, Pavlos I. Tsouvaltzis, Anastasios S. Siomos
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/24/23/7547
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1846123853086982144
author Dimitrios S. Kasampalis
Pavlos I. Tsouvaltzis
Anastasios S. Siomos
author_facet Dimitrios S. Kasampalis
Pavlos I. Tsouvaltzis
Anastasios S. Siomos
author_sort Dimitrios S. Kasampalis
collection DOAJ
description The market demand for baby leaf lettuce is constantly increasing, while safety has become one of the most important traits in determining consumer preference driven by human health hazards concerns. In this study, the performance of visible and near-infrared (vis/NIR) spectroscopy was tested in discriminating pesticide-free against pesticide-treated lettuce plants. Two commercial fungicides (mancozeb and fosetyl-al) and two insecticides (deltamethrin and imidacloprid) were applied as spray solutions at the recommended rates on baby leaf lettuce plants. Untreated-control plants were sprayed with water. Reflectance data in the wavelength range 400–2500 nm were captured on leaf samples until harvest on the 10th day upon pesticide application, as well as after 4 and 8 days during post-harvest storage at 5 °C. In addition, biochemical components in leaf tissue were also determined during storage, such as antioxidant enzymes’ activities (peroxidase [POD], catalase [CAT], and ascorbate peroxidase [APX]), along with malondialdehyde [MDA] and hydrogen peroxide [H<sub>2</sub>O<sub>2</sub>] content. Partial least square discriminant analysis (PLSDA) combined with feature-selection techniques was implemented, in order to classify baby lettuce tissue into pesticide-free or pesticide-treated ones. The genetic algorithm (GA) and the variable importance in projection (VIP) scores identified eleven distinct regions and nine specific wavelengths that exhibited the most significant effect in the detection models, with most of them in the near-infrared region of the electromagnetic spectrum. According to the results, the classification accuracy of discriminating pesticide-treated against non-treated lettuce leaves ranged from 94% to 99% in both pre-harvest and post-harvest periods. Although there were no significant differences in enzyme activities or H<sub>2</sub>O<sub>2</sub>, the MDA content in pesticide-treated tissue was greater than in untreated ones, implying that the chemical spray application probably induced a stress response in the plant that was disclosed with the reflected energy. In conclusion, vis/NIR spectroscopy appears as a promising, reliable, rapid, and non-destructive tool in distinguishing pesticide-free from pesticide-treated lettuce products.
format Article
id doaj-art-a428f17f2b744bcdaa7c6830237cf0e6
institution Kabale University
issn 1424-8220
language English
publishDate 2024-11-01
publisher MDPI AG
record_format Article
series Sensors
spelling doaj-art-a428f17f2b744bcdaa7c6830237cf0e62024-12-13T16:31:53ZengMDPI AGSensors1424-82202024-11-012423754710.3390/s24237547Non-Destructive Detection of Pesticide-Treated Baby Leaf Lettuce During Production and Post-Harvest Storage Using Visible and Near-Infrared SpectroscopyDimitrios S. Kasampalis0Pavlos I. Tsouvaltzis1Anastasios S. Siomos2Department of Horticulture, Aristotle University, 54124 Thessaloniki, GreeceHorticultural Sciences Department, Southwest Florida Research and Education Center, University of Florida, Immokalee, FL 34142, USADepartment of Horticulture, Aristotle University, 54124 Thessaloniki, GreeceThe market demand for baby leaf lettuce is constantly increasing, while safety has become one of the most important traits in determining consumer preference driven by human health hazards concerns. In this study, the performance of visible and near-infrared (vis/NIR) spectroscopy was tested in discriminating pesticide-free against pesticide-treated lettuce plants. Two commercial fungicides (mancozeb and fosetyl-al) and two insecticides (deltamethrin and imidacloprid) were applied as spray solutions at the recommended rates on baby leaf lettuce plants. Untreated-control plants were sprayed with water. Reflectance data in the wavelength range 400–2500 nm were captured on leaf samples until harvest on the 10th day upon pesticide application, as well as after 4 and 8 days during post-harvest storage at 5 °C. In addition, biochemical components in leaf tissue were also determined during storage, such as antioxidant enzymes’ activities (peroxidase [POD], catalase [CAT], and ascorbate peroxidase [APX]), along with malondialdehyde [MDA] and hydrogen peroxide [H<sub>2</sub>O<sub>2</sub>] content. Partial least square discriminant analysis (PLSDA) combined with feature-selection techniques was implemented, in order to classify baby lettuce tissue into pesticide-free or pesticide-treated ones. The genetic algorithm (GA) and the variable importance in projection (VIP) scores identified eleven distinct regions and nine specific wavelengths that exhibited the most significant effect in the detection models, with most of them in the near-infrared region of the electromagnetic spectrum. According to the results, the classification accuracy of discriminating pesticide-treated against non-treated lettuce leaves ranged from 94% to 99% in both pre-harvest and post-harvest periods. Although there were no significant differences in enzyme activities or H<sub>2</sub>O<sub>2</sub>, the MDA content in pesticide-treated tissue was greater than in untreated ones, implying that the chemical spray application probably induced a stress response in the plant that was disclosed with the reflected energy. In conclusion, vis/NIR spectroscopy appears as a promising, reliable, rapid, and non-destructive tool in distinguishing pesticide-free from pesticide-treated lettuce products.https://www.mdpi.com/1424-8220/24/23/7547chemometricsantioxidant enzymesdiscriminationfeature extractionpartial least squares
spellingShingle Dimitrios S. Kasampalis
Pavlos I. Tsouvaltzis
Anastasios S. Siomos
Non-Destructive Detection of Pesticide-Treated Baby Leaf Lettuce During Production and Post-Harvest Storage Using Visible and Near-Infrared Spectroscopy
Sensors
chemometrics
antioxidant enzymes
discrimination
feature extraction
partial least squares
title Non-Destructive Detection of Pesticide-Treated Baby Leaf Lettuce During Production and Post-Harvest Storage Using Visible and Near-Infrared Spectroscopy
title_full Non-Destructive Detection of Pesticide-Treated Baby Leaf Lettuce During Production and Post-Harvest Storage Using Visible and Near-Infrared Spectroscopy
title_fullStr Non-Destructive Detection of Pesticide-Treated Baby Leaf Lettuce During Production and Post-Harvest Storage Using Visible and Near-Infrared Spectroscopy
title_full_unstemmed Non-Destructive Detection of Pesticide-Treated Baby Leaf Lettuce During Production and Post-Harvest Storage Using Visible and Near-Infrared Spectroscopy
title_short Non-Destructive Detection of Pesticide-Treated Baby Leaf Lettuce During Production and Post-Harvest Storage Using Visible and Near-Infrared Spectroscopy
title_sort non destructive detection of pesticide treated baby leaf lettuce during production and post harvest storage using visible and near infrared spectroscopy
topic chemometrics
antioxidant enzymes
discrimination
feature extraction
partial least squares
url https://www.mdpi.com/1424-8220/24/23/7547
work_keys_str_mv AT dimitriosskasampalis nondestructivedetectionofpesticidetreatedbabyleaflettuceduringproductionandpostharveststorageusingvisibleandnearinfraredspectroscopy
AT pavlositsouvaltzis nondestructivedetectionofpesticidetreatedbabyleaflettuceduringproductionandpostharveststorageusingvisibleandnearinfraredspectroscopy
AT anastasiosssiomos nondestructivedetectionofpesticidetreatedbabyleaflettuceduringproductionandpostharveststorageusingvisibleandnearinfraredspectroscopy