Food Engineering Research

Current Issue

By Issue

By Author

By Subject

Author Index

Keyword Index

About Journal

Aims and Scope

Publication Ethics

Indexing and Abstracting

FAQ

Peer Review Process

Journal Metrics

News

Design and Evaluation of a Capacitive Sensor System for Non-Destructive Determination of Tomato Ripeness

Document Type : Research Paper

Authors

1 دانشگاه علوم کشاورزی و منابع طبیعی گرگان

2 Department of Biosystems Mechanical Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan,

10.22092/fooder.2026.373228.1465

Abstract

In this study, a parallel-plate capacitive sensor system was designed, developed, and evaluated for the non-destructive assessment of tomato ripeness. The primary objective was to investigate the system's capability to estimate the quality and physicochemical characteristics of tomatoes based on variations in their dielectric properties. Tomato samples were classified into three diameter groups and tested under a completely randomized design. The capacitance of the samples was measured using an RC circuit integrated with an Arduino UNO board. In addition, physical properties , mechanical properties and chemical properties (pH, titratable acidity, and total soluble solids) were determined under laboratory conditions. Data were analyzed using SAS software within a completely randomized design framework. The effects of plate spacing and sample diameter were evaluated through analysis of variance (ANOVA), and mean comparisons were conducted using the LSD test at the 5% significance level. The results indicated that fruit diameter had a significant effect on most physical and chemical properties, whereas plate spacing primarily influenced the samples' dielectric response. Moreover, the interaction effect of plate spacing and fruit diameter on the dielectric constant was significant at the 1% probability level, demonstrating the high sensitivity of the developed sensor system. Increasing fruit diameter increased the dielectric constant and decreased parameters such as (°Brix) and firmness. In contrast, variations in plate spacing did not significantly affect the physical and chemical characteristics of the samples. Overall, the findings demonstrated that the proposed capacitive sensing system is a promising tool for the non-destructive evaluation of tomato ripeness.

Keywords

Main Subjects

References
Azadbakht, M., Mahmoodi, M. J., Torshizi, M. V., & Kashi, P. A. (2020). Relationship of pears’ dielectric properties and rates of pears’ bruise. Agricultural Engineering International: CIGR Journal, 22(1), 169–179.
Azadbakht, M., Torshizi, M. V., Khatunabadi, A. S., & Tajari, M. (2026). Synergistic mitigation of bruising in red delicious: A non-destructive evaluation of polyamine (spermidine), chitosan coatings, and optimized packaging using CT-scan imaging and principal component analysis. Postharvest Biology and Technology, 236, 114241.
Azadbakht, M., Vahedi, M., & Mahmoodi, M. J. (2019). The relation of pear volume and it’s bruised volume by CT scan imaging. Journal of Food Measurement and Characterization, 7(3). https://doi.org/10.1007/s11694-018-00024-0
Azadbakht, M., Vahedi Torshizi, M., & Mahmoodi, M. J. (2019a). Determination amount of pear bruises due to wide edge pressure via CT scan method and relation them with some physical properties pear. Journal of Food Science and Technology (Iran), 16(92), 153–163.
Azadbakht, M., Vahedi Torshizi, M., & Mahmoodi, M. J. (2019b). Determination of pear bruises due to a thin edge compression load by CT scan method. Innovative Food Technologies, 6(3), 305–321. https://doi.org/10.22104/jift.2018.2842.1684
Castro-Giráldez, M., Botella, P., Toldrá, F., & Fito, P. (2010). Low-frequency dielectric spectrum to determine pork meat quality. Innovative Food Science and Emerging Technologies, 11(2), 376–386. https://doi.org/10.1016/j.ifset.2010.01.011
Feng, H., Tang, J., & Cavalieri, R. P. (2002). Dielectric Properties of Dehydrated Apples as Affected by Moisture and Temperature. Transactions of the American Society of Agricultural Engineers, 45(1), 129–135. https://doi.org/10.13031/2013.7855
Funebo, T., & Ohlson, T. (1999a). Dielectric Properties of Fruits and Vegetables as a Function of Temperature and Moisture Content Dielectric Properties of Fruits and Vegetables as a Function of Temperature and Moisture Content. Journal of Microwave Power and Electromagnetic Energy, 34(1), 42–54. https://doi.org/10.1080/08327823.1999.11688387
Funebo, T., & Ohlson, T. (1999b). Dielectric Properties of Fruits and Vegetables as a Function of Temperature and Moisture Content Dielectric Properties of Fruits and Vegetables as a Function of Temperature and Moisture Content. Journal of Microwave Power and Electromagnetic Energy, 34(1), 42–54.
Garcı́a, A., Torres, J. L., De Blas, M., De Francisco, A., & Illanes, R. (2004). Dielectric Characteristics of Grape Juice and Wine. Biosystems Engineering, 88(3), 343–349. https://doi.org/10.1016/j.biosystemseng.2004.04.008
Jiao, S., Johnson, J. A., Tang, J., Tiwari, G., Wang, S. (2011). Dielectric properties of cowpea weevil, black-eyed peas and mung beans with respect to the development of radio frequency heat treatments. Biosystems Engineering, 108(3), 280–291.
Little, C. R., & Holmes, R. J. (2000). Storage technology for apples and pears. Department of Natural Resources and Economics, Victoria.
McKeown, M. S., Trabelsi, S., Tollner, E. W., & Nelson, S. O. (2012). Dielectric spectroscopy measurements for moisture prediction in Vidalia onions. Journal of Food Engineering, 111(3), 505–510. https://doi.org/10.1016/j.jfoodeng.2012.02.034
Naderi-Boldaji, M., Fazeliyan-Dehkordi, M., Mireei, S. A., & Ghasemi-Varnamkhasti, M. (2015). Dielectric power spectroscopy as a potential technique for the non-destructive measurement of sugar concentration in sugarcane. Biosystems Engineering, 140(i), 1–10. https://doi.org/10.1016/j.biosystemseng.2015.09.003
Nelson, S. O., & Jr, P. G. B. (2000). MEASURING FREQUENCY- AND TEMPERATURE-DEPENDENT DIELECTRIC PROPERTIES OF FOOD MATERIALS. American Society of Agricultural Engineers.
Soltani, M., Alimardani, R., & Omid, M. (2011a). Evaluating banana ripening status from measuring dielectric properties. Journal of Food Engineering, 105(4), 625–631. https://doi.org/10.1016/j.jfoodeng.2011.03.032
Wang, S., Monzon, m., Gazit, Y., tang, J., Mitcham, E. J., Armstrang, J. W. (2005). Temperaturedependent dielectric properties of selected subtropical and tropical fruits and associated insect pests. Transactions of the ASAE, 48(8), 1873-1881
Food Engineering Research
Volume 25, Issue 2
September 2026
Pages 61-78
Files
Share
How to cite
Statistics