Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with Chemometrics

Postharvest kiwifruit continues to ripen for a period until it reaches the optimal “eating ripe„ stage. Without damaging the fruit, it is very difficult to identify the ripeness of postharvest kiwifruit by conventional means. In this study, an electronic nose (E-nose) with 10 met...

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Main Authors: Dongdong Du, Jun Wang, Bo Wang, Luyi Zhu, Xuezhen Hong
Format: Article
Language:English
Published: MDPI AG 2019-01-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/19/2/419
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author Dongdong Du
Jun Wang
Bo Wang
Luyi Zhu
Xuezhen Hong
author_facet Dongdong Du
Jun Wang
Bo Wang
Luyi Zhu
Xuezhen Hong
author_sort Dongdong Du
collection DOAJ
description Postharvest kiwifruit continues to ripen for a period until it reaches the optimal &#8220;eating ripe&#8222; stage. Without damaging the fruit, it is very difficult to identify the ripeness of postharvest kiwifruit by conventional means. In this study, an electronic nose (E-nose) with 10 metal oxide semiconductor (MOS) gas sensors was used to predict the ripeness of postharvest kiwifruit. Three different feature extraction methods (the max/min values, the difference values and the 70th s values) were employed to discriminate kiwifruit at different ripening times by linear discriminant analysis (LDA), and results showed that the 70th s values method had the best performance in discriminating kiwifruit at different ripening stages, obtaining a 100% original accuracy rate and a 99.4% cross-validation accuracy rate. Partial least squares regression (PLSR), support vector machine (SVM) and random forest (RF) were employed to build prediction models for overall ripeness, soluble solids content (SSC) and firmness. The regression results showed that the RF algorithm had the best performance in predicting the ripeness indexes of postharvest kiwifruit compared with PLSR and SVM, which illustrated that the E-nose data had high correlations with overall ripeness (training: R<sup>2</sup> = 0.9928; testing: R<sup>2</sup> = 0.9928), SSC (training: R<sup>2</sup> = 0.9749; testing: R<sup>2</sup> = 0.9143) and firmness (training: R<sup>2</sup> = 0.9814; testing: R<sup>2</sup> = 0.9290). This study demonstrated that E-nose could be a comprehensive approach to predict the ripeness of postharvest kiwifruit through aroma volatiles.
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spelling doaj.art-3a71267d67434e108ad6b7c4600a74762022-12-22T04:23:25ZengMDPI AGSensors1424-82202019-01-0119241910.3390/s19020419s19020419Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with ChemometricsDongdong Du0Jun Wang1Bo Wang2Luyi Zhu3Xuezhen Hong4College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, ChinaCollege of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, ChinaCollege of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, ChinaCollege of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, ChinaKey Laboratory of On Site Processing Equipment for Agricultural Products, Ministry of Agriculture and Rural Affairs, Hangzhou 310058, ChinaPostharvest kiwifruit continues to ripen for a period until it reaches the optimal &#8220;eating ripe&#8222; stage. Without damaging the fruit, it is very difficult to identify the ripeness of postharvest kiwifruit by conventional means. In this study, an electronic nose (E-nose) with 10 metal oxide semiconductor (MOS) gas sensors was used to predict the ripeness of postharvest kiwifruit. Three different feature extraction methods (the max/min values, the difference values and the 70th s values) were employed to discriminate kiwifruit at different ripening times by linear discriminant analysis (LDA), and results showed that the 70th s values method had the best performance in discriminating kiwifruit at different ripening stages, obtaining a 100% original accuracy rate and a 99.4% cross-validation accuracy rate. Partial least squares regression (PLSR), support vector machine (SVM) and random forest (RF) were employed to build prediction models for overall ripeness, soluble solids content (SSC) and firmness. The regression results showed that the RF algorithm had the best performance in predicting the ripeness indexes of postharvest kiwifruit compared with PLSR and SVM, which illustrated that the E-nose data had high correlations with overall ripeness (training: R<sup>2</sup> = 0.9928; testing: R<sup>2</sup> = 0.9928), SSC (training: R<sup>2</sup> = 0.9749; testing: R<sup>2</sup> = 0.9143) and firmness (training: R<sup>2</sup> = 0.9814; testing: R<sup>2</sup> = 0.9290). This study demonstrated that E-nose could be a comprehensive approach to predict the ripeness of postharvest kiwifruit through aroma volatiles.https://www.mdpi.com/1424-8220/19/2/419electronic nosenondestructive detectionkiwifruitripenessSSCfirmness
spellingShingle Dongdong Du
Jun Wang
Bo Wang
Luyi Zhu
Xuezhen Hong
Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with Chemometrics
Sensors
electronic nose
nondestructive detection
kiwifruit
ripeness
SSC
firmness
title Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with Chemometrics
title_full Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with Chemometrics
title_fullStr Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with Chemometrics
title_full_unstemmed Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with Chemometrics
title_short Ripeness Prediction of Postharvest Kiwifruit Using a MOS E-Nose Combined with Chemometrics
title_sort ripeness prediction of postharvest kiwifruit using a mos e nose combined with chemometrics
topic electronic nose
nondestructive detection
kiwifruit
ripeness
SSC
firmness
url https://www.mdpi.com/1424-8220/19/2/419
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AT bowang ripenesspredictionofpostharvestkiwifruitusingamosenosecombinedwithchemometrics
AT luyizhu ripenesspredictionofpostharvestkiwifruitusingamosenosecombinedwithchemometrics
AT xuezhenhong ripenesspredictionofpostharvestkiwifruitusingamosenosecombinedwithchemometrics