Using Light Delays to Track Tomato Ripening and Sort by Maturity

Jenn Hoskins
21st May, 2024

Using Light Delays to Track Tomato Ripening and Sort by Maturity

Image Source: Natural Science News, 2024

Key Findings

  • The study by the Università di Catania explored Delayed Luminescence (DL) to assess tomato ripeness and quality during postharvest storage
  • DL signals varied significantly with ripening stages, showing higher intensity in unripe tomatoes and lower intensity in fully ripe tomatoes
  • DL measurements distinguished postharvest-ripened tomatoes from field-ripened ones, offering a rapid and non-destructive quality assessment tool
Tomato ripening is a complex process involving various physiological, biochemical, and sensory changes that affect the fruit's nutritional value, color, texture, and taste. Understanding and monitoring these changes are crucial for improving postharvest management and ensuring high-quality produce for consumers. A recent study by the Università di Catania has explored the potential of Delayed Luminescence (DL) as a non-destructive tool to assess the ripening stages and quality of tomatoes[1]. Delayed Luminescence (DL) refers to the weak light emission from biological systems after exposure to light. This phenomenon has been shown to provide valuable insights into the functional status of living tissues, reflecting metabolic changes and quality parameters. In this study, researchers monitored DL signals emitted by tomatoes at various ripening stages and correlated these signals with the a*/b* color ratio, a standard indicator of fruit ripeness. Four lots of tomatoes, similar in cultivar and geographical origin, were harvested at different maturity stages and stored in the dark at room temperature. Over a period of about 20 days, the researchers tracked the variations in DL emission intensities and analyzed the DL decay curves. They found that DL signals varied significantly with the ripening degree, showing marked differences between field-ripened tomatoes at the beginning of storage and postharvest-ripened tomatoes at the end of the storage period. This study builds on previous research that has explored various non-destructive methods for assessing tomato ripeness and quality. For instance, earlier studies have demonstrated the use of handheld Raman spectroscopy combined with pattern recognition techniques to profile and quantify tomato carotenoids non-invasively[2]. Raman spectroscopy, equipped with a 1064 nm excitation laser, provided accurate classification and quantification of carotenoids like all-trans-lycopene and β-carotene, which are important indicators of tomato ripeness and nutritional value. This method achieved high accuracy in clustering samples and predicting carotenoid levels, making it a valuable tool for tomato breeders and producers. Similarly, another study used a Minolta Chroma meter to measure tomato surface color and correlated these measurements with lycopene content, a key carotenoid linked to ripeness[3]. The study found that parameters such as the a/b ratio and lycopene content allowed for the statistical distinction of six out of seven maturity groups. This correlation provided a practical approach for estimating lycopene content in tomatoes using portable colorimeters, which could be useful for field applications. The current study by the Università di Catania adds to this body of knowledge by highlighting the potential of DL as a rapid, reliable, and sensitive method for evaluating tomato ripeness and quality during postharvest storage. The findings indicate that DL emission intensities and decay parameters are strongly dependent on the harvest maturity and ripening progression, offering a new avenue for non-destructive quality assessment in tomatoes. In conclusion, the integration of DL with other non-invasive techniques like Raman spectroscopy and colorimetry can provide a comprehensive toolkit for monitoring tomato ripeness and quality. These methods offer significant advantages for producers, breeders, and researchers, enabling better management of postharvest processes and ensuring high-quality tomatoes for consumers. The study by the Università di Catania underscores the importance of continued research in this field to develop practical and effective solutions for the agricultural industry.

FruitsAgriculturePlant Science


Main Study

1) Delayed Luminescence in Monitoring the Postharvest Ripening of Tomato Fruit and Classifying According to Their Maturity Stage at Harvest

Published 20th May, 2024

Related Studies

2) High-Throughput Phenotyping Approach for Screening Major Carotenoids of Tomato by Handheld Raman Spectroscopy Using Chemometric Methods.

3) Correlation of lycopene measured by HPLC with the L, a, b color readings of a hydroponic tomato and the relationship of maturity with color and lycopene content.

Journal: Journal of agricultural and food chemistry, Issue: Vol 48, Issue 5, May 2000

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