Sweetness and Antioxidant Indices of Mango (Mangifera indica cv. Nam Dok Mai Sithong) using Red–Green–Blue and Near-Infrared Images
Main Article Content
Abstract
This study aimed to develop a simple method for the non-destructive evaluation of Nam Dok Mai Sithong mango quality indices. One hundred and fifty mangoes (Mangifera indica cv. Nam Dok Mai Sithong) were stored at room temperature for 10 days to evaluate image-based indices for non-destructive quality prediction. Physicochemical properties and image data were collected every two days. Red–green–blue (RGB) and near-infrared images were acquired using visible and infrared filters, respectively. RGB values were extracted using MATLAB. The Nam Dok Mai Sithong index (NDMSTI) was computed using the Normalized Difference Vegetation Index principle. Its predictive performance was compared with that of other RGB-based indices for mango chemical properties. Correlation analysis and partial least squares regression were applied. Model performance was validated using leave-one-out cross-validation. The models were evaluated using the coefficient of determination (R2CV) and root mean square error of cross-validation (RMSECV). Both the Normalized Green Blue Different Index (NGBDI) and NDMSTI showed statistically significant predictive performance for all chemical properties (p < 0.01). Performance was stronger for sweetness (total soluble solids) and antioxidants (ABTS). NDMSTI performed comparably to NGBDI, with slightly lower R2CV and slightly higher RMSECV. These results indicate that NDMSTI has potential as a non-destructive tool for monitoring mango quality during storage.
Article Details

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
References
Penchaiya, P.; Tijskens, L.M.M.; Uthairatanakij, A.; Srilaong, V.; Tansakul, A.; Kanlayanarat, S. Modelling quality and maturity of ‘Namdokmai Sithong’ mango and their variation during storage. Postharvest Biol. Technol. 2020, 159, 111000. https://doi.org/10.1016/j.postharvbio.2019.111000
Kuntanavit, P. The Exports of mangoes, bananas, durian and mangosteen from Thailand to Japan under the Japan-Thailand economic partnership agreement (JTEPA); Research report; National Commission on Science, Research and Innovation (CSRP), 2020.
Salengke, S.; Mursalim. Non-destructive technique for determining mango maturity. Acta Hortic. 2013, 975, 505-512. https://doi.org/10.17660/ActaHortic.2013.975.66.
Arias, A.; Feijoo, G.; Moreira, M.T. Exploring the potential of antioxidants from fruits and vegetables and strategies for their recovery. Innov. Food Sci. Emerg. Technol. 2022, 77, 102974. https://doi.org/10.1016/j.ifset.2022.102974
Liu, X.; Fu, Y.; Li, M.; Xiong, S.; Huang, L.; Zhang, S.; Zhang, W.; Liang, X.; Wang, W.; Tang, K.; Shen, Q. Biofortification of tomatoes with beta-carotene through targeted gene editing. Int. J. Biol. Macromol. 2025, 327, 147396. https://doi.org/10.1016/j.ijbiomac.2025.147396
Yungyuen, W.; Vo, T.T.; Uthairatanakij, A.; Ma, G.; Zhang, L.; Tatmala, N.; Kaewsuksaeng, S.; Jitareerat, P.; Kato, M. Carotenoid accumulation and the expression of carotenoid metabolic genes in mango during fruit development and ripening. Appl. Sci. 2021, 11, 9. https://doi.org/10.3390/app11094249
Ali, M.; Anwar, R.; Yousef, A.F.; Li, B.; Luvisi, A.; Bellis, L.D.; Aprile, A.; Chen, F. Influence of bagging on the development and quality of fruits. Plants. 2021, 10, 358. https://doi.org/10.3390/plants10020358.
Penchaiya, P.; Uthairatanakij, A.; Srilaong, V.; Kanlayanarat, S.; Tijskens, L.; Tansakul, A. Measurement of Mango Firmness by Non-Destructive Limited Compression Technique. Acta Horticulturae, 2015, 1088, 73–78. https://doi.org/10.17660/ActaHortic.2015.1088.7
Sangchote, S. Integrated control of anthracnose (Colletotrichum gloeosporioides) of mango for export. Acta Horticulturae. 2013, 973, 55–58. https://doi.org/10.17660/ActaHortic.2013.973.5
Dabas, V.; Jaiswal, G.; Agarwal, M.; Rani, R.; Sharma, A. Construction of hyperspectral images from RGB images via CNN. Multimedia Tools Appl. 2025, 84(11), 8725–8744. https://doi.org/10.1007/s11042-024-19289-3
Lekhawattana, W.; Sirisomboon, P. Overall precision test of near infrared spectroscopy on mango fruits ( Mangifera indica CV. ‘Nam Dok Mai Si Thong’) by on-line and off-line systems. E3S Web Conf. 2020, 187, 04006. https://doi.org/10.1051/e3sconf/202018704006
Rungpichayapichet, P.; Chaiyarattanachote, N.; Khuwijitjaru, P.; Nakagawa, K.; Nagle, M.; Müller, J.; Mahayothee, B. Comparison of near-infrared spectroscopy and hyperspectral imaging for internal quality determination of ‘Nam Dok Mai’ mango during ripening. J. Food Meas. Charact. 2023, 17, 1501–1514. https://doi.org/10.1007/s11694-022-01715-5
Gkillas, A.; Kosmopoulos, D.; Berberidis, K. Cost-efficient coupled learning methods for recovering near-infrared information from RGB signals: Application in precision agriculture. Comput. Electron. Agricult. 2023, 209, 107833. https://doi.org/10.1016/j.compag.2023.107833
Kasimati, A.; Psiroukis, V.; Darra, N.; Kalogrias, A.; Kalivas, D.; Taylor, J.A.; Fountas, S. Investigation of the similarities between NDVI maps from different proximal and remote sensing platforms in explaining vineyard variability. Precis. Agricult. 2023, 24(4), 1220–1240. https://doi.org/10.1007/s11119-022-09984-2
Rabatel, G., Gorretta, N. and Labbé, S., 2011, November. Getting NDVI spectral bands from a single standard RGB digital camera: a methodological approach. In Conference of the Spanish Association for Artificial Intelligence (pp. 333-342). Berlin, Heidelberg: Springer Berlin Heidelberg.
Bhandari, A.; Kumar, A.; Singh, G. Feature extraction using normalized difference vegetation index (NDVI): a case study of Jabalpur City. Procedia Technol. 2012, 6, 612–621. https://doi.org/10.1016/j.protcy.2012.10.074
Liu, B.; Xin, Q.; Zhang, M.; Chen, J.; Lu, Q.; Zhou, X.; Li, X.; Zhang, W.; Feng, W.; Pei, H.; Sun, J. Research progress on mango post-harvest ripening physiology and the regulatory technologies. Foods 2023, 12(1), 173. https://doi.org/10.3390/foods12010173
Rooban, R.; Shanmugam, M.; Venkatesan, T.; Tamilmani, C. Physiochemical changes during different stages of fruit ripening of climacteric fruit of mango (Mangifera indica L.) and non-climacteric of fruit cashew apple (Anacardium occidentale L.). J. Appl. Adv. Res. 2016, 1, 53. https://doi.org/10.21839/jaar.2016.v1i2.27
Galal, H.; Elsayed, S.; Elsherbiny, O.; Allam, A.; Farouk, M. Using RGB imaging, optimized three-band spectral indices, and a decision tree model to assess orange fruit quality. Agricult. 2022, 12(10), 1558. https://doi.org/10.3390/agriculture12101558
Kawashima, S.; Nakatani, M. An algorithm for estimating chlorophyll content in leaves using a video camera. Ann. Bot. 1998, 81(1), 49–54. https://doi.org/10.1006/anbo.1997.0544
Montanaro, G.; Petrozza, A.; Rustioni, L.; Cellini, F.; Nuzzo, V. Phenotyping key fruit quality traits in olive using RGB images and back propagation neural networks. Plant Phenomics. 2023, 5, 0061. https://doi.org/10.34133/plantphenomics.0061
Phimphimol, J. Sorting maturity of mangoes (Mangifera indica L.) cv. Kaew by floating in salt solution. J. Agric. Res. Ext. 1999, 16(1), 1–10. http://mdc.library.mju.ac.th/article/61802/298644/349014.pdf
Somkane, S. The Effect of freezing onthe osmotic dehydration process and the quality of osmo-air-dried mangoes. Master of Science. Thesis. Silpakorn University. 2020.
Khalifa, S.; Abobatta, W. Climate changes and mango production (temperature). IgMin Res. 2023, 1(1), 043–046. https://doi.org/10.61927/igmin115
Walpole, R. E.; Myers, R. H.; Myers, S. L.; Ye, K. Probability & Statistics for Engineers & Scientists., 9th ed.; Prentice Hall, 2012.
Hogg, R. V.; Tanis, E. A.; Zimmerman, D. L. Probability and Statistical Inference, 9th ed.; Pearson, 2015.https://faculty.ksu.edu.sa/sites/default/files/677_fr37hij.pdf
Sa-Ngadsup, P.; Kiyoki, Y.; Koopipat, C. In vitro coral bleach observation using an RGB-IR camera. Front. Artif. Intel. Appl., 2019, 312, 457–468. https://doi.org/10.3233/978-1-61499-933-1-457
Brand-Williams, W.; Cuvelier, M.E.; Berset, C. Use of a free radical method to evaluate antioxidant activity. LWT Food Sci. Technol. 1995, 28(1), 25–30. https://doi.org/10.1016/S0023-6438(95)80008-5
Re, R.; Pellegrini, N.; Proteggente, A.; Pannala, A.; Yang, M.; Rice-Evans, C. Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radical Biol. Med. 1999, 26(9), 1231–1237. https://doi.org/10.1016/S0891-5849(98)00315-3
de Winter, J.; Gosling, S.; Potter, J. Comparing the Pearson and Spearman correlation coefficients across distributions and sample sizes: A tutorial using simulations and empirical data. Psychol. Methods 2016, 21, 273–290. https://doi.org/10.1037/met0000079.supp
Willaby, H.; Costa, D.; Burns, B.; Maccann, C.; Roberts, R. Testing complex models with Small Sample sizes: A historical overview and empirical demonstration of what partial least squares (PLS) can offer differential psychology. Personal. Individ. Diff. 2015, 84, 73–78. https://doi.org/10.1016/j.paid.2014.09.008
Tucker, C.J. Red and photographic infrared linear combinations for monitoring vegetation. Remote Sens. Environ. 1979, 8(2), 127–150. https://doi.org/10.1016/0034-4257(79)90013-0
Du, M.; Noguchi, N. Monitoring of wheat growth status and mapping of wheat yield’s within-field spatial variations using color images acquired from a UAV-camera system. Remote Sens. 2017, 9(3), 289. https://doi.org/10.3390/rs9030289
Min, S.; Kaewtrakulpong, K.; Phaosang, T.; Sermsak, R. Image processing method to check maturity index of "Sein Ta Lone" mango in Myanmar. Suranaree J. Sci. Technol. 2024, 29.
Rungpichayapichet, P.; Mahayothee, B.; Khuwijitjaru, P.; Nagle, M.; Müller, J. Non-destructive determination of β-carotene content in mango by near-infrared spectroscopy compared with colorimetric measurements. J. Food Compos. Anal. 2015, 38, 32–41. https://doi.org/10.1016/j.jfca.2014.10.013
Elsayed, S.; Galal, H.; Allam, A.; Schmidhalter, U. Passive reflectance sensing and digital image analysis for assessing quality parameters of mango fruits. Scientia Hortic. 2016, 212, 136–147. https://doi.org/10.1016/j.scienta.2016.09.046