Development of a prediction model for the pericarp CIE a* value of mature green tomato at different storage temperatures as a function of cumulative ethylene production

https://doi.org/10.1016/j.jfoodeng.2020.109945Get rights and content

Highlights

  • CIE a* of MG tomato during storage was modeled by cumulative ethylene.

  • A sigmoid function based model was development at 12, 15, 20 and 25 °C.

  • Proposed model is applicable not only at 25 °C but also at other temperatures.

  • Model parameters at 15 °C were estimated based on parameters at 12 and 20 °C.

  • Addition of data at different storage temperatures will improve the goodness of fit.

Abstract

An estimation model following the sigmoid function of pericarp color based on the cumulative ethylene production was proposed. In the first part of the experiment, the same quintuplet samples were stored at 15 and 25 °C, respectively. In the second part, 114 tomatoes were stored at 12, 15, and 20 °C, and different triplet samples were used every time. It was concluded that the proposed model well described the behavior of the change in pericarp color in different storage temperatures. Moreover, the goodness of fit was better when the same sample was used. Another estimation method of parameters α, β, and γ of the sigmoid function at 15 °C was performed based on a linear regression using parameters α, β, and γ obtained at 12 and 20 °C. It suggested that the improvement of the goodness of fit will be achieved by the addition of data at different storage temperatures.

Introduction

In view of the rapid growth of the international trade of fresh agricultural products, fresh produce of high quality is needed when it reaches the consumer. However, fresh produce inevitably loses its freshness and quality during long-term storage and long-distance transportation and becomes unsuitable for consumption. Biswas et al. (2012) reported that tomatoes that were harvested at the same time, at the same maturity stage, and stored under the same condition showed nonuniform color at the end of the storage period, which is undesirable in the supply chain of the tomato industry. According to Lana et al. (2006) and Pinheiro et al. (2013), color is considered a good indicator of the quality of fresh fruits and vegetables. Therefore, understanding how these attributes change after harvesting is fundamental to establish good management practices in the industry and during distribution and marketing. In addition to the quality parameter, color also considered as one of ripening indicator, due to the dramatic change of color during ripening are visible to the naked eyes. (Trebolazabala et al., 2017, Wu et al., 2018).

Regarding postharvest losses, there are several major caused by postharvest losses, and they are multidimensional and complex (Sheahan and Barrett, 2017). In tomato, one of them is the color nonuniformity. The non-uniform color of the tomatoes is not only one of the major caused of postharvest losses but also potentially be the food safety risk due to the higher occurrence of spoilage from the mixed presence of over-ripe and immature tomato (Qin et al., 2011).

Based on the skin color of the tomato, the United States Department of Agriculture (USDA) established six ripening stages: green, breaker, turning, pink, light red, and red. The recommended harvesting stage for typical red tomatoes is at the mature green, breaker, or pink stages, depending on the distribution process (Chomchalow et al., 2002, Wills and Ku, 2002). As the fruit has a climacteric-ripening pattern (Hoeberichts et al., 2002), the shelf life of tomato is relatively short. Harvested tomato at the mature green, breaker, or pink stages will have a longer shelf life compared to the other stages (light red and red) and leads to reduced losses due to spoilage. Furthermore, according to Qin et al. (2011), there is four maturity stage of green tomato (i.e., M1-M4). Tomatoes harvested at M1 (immature-green stage) will not ripen or reach the quality suitable for consumption. While tomatoes harvested at M2, they will ripen into moderate quality, and tomatoes harvested at M3-M4 (mature green stage) will ripen into a high-quality tomato. Therefore, observation of the ripening behavior of tomatoes that were harvested at the mature green stage and stored at different storage temperature conditions is necessary. Even though harvesting tomatoes at the mature green stage of development is not conventional in Japan, referring to Qin et al. (2011) in other countries, tomato is harvested at different maturity stages, including mature green stage to satisfy different consumption requirements in the tomato production industry.

It has been known that ripening is associated with the development in red color and onset of the rise in ethylene production of the tomato fruit. During maturation, the storage temperature becomes one of the most critical factors that determine how quickly the red color will develop, and the ethylene will burst. So far, however, there have been several different statements regarding the optimal storage temperature for tomato. It was suggested that the compromise storage temperature for most varieties of tomato is 12 °C (Lurie and Sabehat, 1997). On the other hand, Park et al. (2018b) reported that the optimum storage condition is 18 °C–21 °C for typical standard size red tomatoes. It has also been broadly reported that the increase in ethylene production rate or the addition of ethylene treatment will accelerate red color development in mature green tomato during ripening process (Chomchalow et al., 2002, Domínguez et al., 2016, Hurr et al., 2005, Saltveit, 1999, Wu et al., 2018). Momotaro is the most widely grown tomato cultivar in Japan, and Momotaro York is one of its derivatives. Momotaro York is characterized as round, deep pink color, 220–230 g in average fruit size, and relatively long shelf life (Kaya, 1997). However, most of the study in Momotaro York was reported the plant growth in preharvest stage (Fujiwara et al., 2011, Higashide et al., 2017, Higashide et al., 2015, Higashide et al., 2014, Matsuda et al., 2013, Matsuda et al., 2011b, Matsuda et al., 2011a, Zhang et al., 2018, Zhang et al., 2015). No report on the ripening indicator such as ethylene production rate or red color development of Momotaro York tomato was found. That is why the observation of ethylene production rate and red color development of Momotaro York tomato at different storage temperature conditions is essential.

Since the non-destructive evaluation method has been a prominence study, the determination of fruit maturity and post-harvest qualities based on non-destructive methods has been widely reported (Wanitchang et al., 2011). Evaluation of the maturity stage of tomato by using color image analysis has also been well known (Choi et al., 1995, Liñero et al., 2017). Furthermore, prediction models for change in color of tomato at different conditions to predict the maturity stage have been developed (Schouten et al., 2007, Thai et al., 1990, Tijskens and Evelo, 1994). However, those prediction models were based on the color parameters, and only Nakamura et al. (2010) reported the color prediction method based on the cumulative ethylene production. In that report, the sigmoid function model was used for describing the relationship between the pericarp color CIE a* values and the cumulative ethylene production of tomato (cv. Momotaro). This model showed a good correlation between the experimental data and predicted data. A further report by Nakamura et al. (2011) revealed that the proposed model could be used for other cultivars with different genetic backgrounds for the RIPENING INHIBITOR gene (RIN/RIN or RIN/rin). However, the report only covers the storage temperature of 25 °C. In this report, we developed the models not only at 25 °C but also at other storage temperatures. The development of models at different storage temperatures will contribute to developing an optimum storage temperature regime for controlling the ripening speed.

In this study, we, therefore, focused on the ripening behavior of mature green tomato and aimed at developing a model for describing the relationship between the change in pericarp color (CIE a* value) and cumulative ethylene production at different storage temperatures using the sigmoid function. The experiment was divided into two parts, namely the first part (15 and 25 °C) and the second part (12, 15, and 20 °C). Aside from the storage temperature, the differences between the first and second parts of the experiment were the sample number. In the first part of the experiment (RI), the same quintuplet sample was used for 35 days of storage the same as the previous report (Nakamura et al., 2010, Nakamura et al., 2011). On the other hand, in the second part of the experiment (RII), different triplet samples were used every time during storage. The first part of the experiment aims to compare the current research result with the previous research obtained by Nakamura et al. (2010), while the second part of the experiment was aimed to observe the goodness of the proposed model when different samples were used in tracing the color change. It enables us to do further comprehensive researches from the second part of the experiment. Because, by using the different samples, destructive analyses, including targeted chemical analysis, chemometrics, metabolomics, transcriptomics, proteomics, etc., can be conducted. Furthermore, the objective of the second part of the experiment was to verify the possibility of the estimation method for determining the parameters α, β, and γ in the sigmoid function at certain storage temperatures using the parameters obtained at other storage temperatures. In this study, the regression analysis at 15 °C based on the parameters obtained at 12 and 20 °C and comparison between these results and the results from the sigmoid function regression at 15 °C by the coefficient of determination has been conducted.

Section snippets

The first part of the experiment (RI)

A total of 10 tomatoes (Solanum lycopersicum L., cv. ‘Momotaro York’, Takii Co., Ltd., Kyoto, Japan) were obtained from a greenhouse in Matsudo campus, Chiba University (Matsudo city, Chiba, Japan). Momotaro York is one of the most popular tomato cultivars in Japan, introduced in 1996 (Sumida et al., 2008). Momotaro York bears large fruits (ca. 150–300 g fresh weight) with dry matter content ranged 0.057–0.062 g g−1 (Higashide et al., 2015, Matsuda et al., 2011b). The fruits were hand-picked on

Ethylene production rate

Ethylene is a plant hormone involved in fruit, flower, and leaf senescence (Kim et al., 2015). In climacteric fruit, the increase in respiration and ethylene synthesis during the climacteric phase is required for normal fruit ripening. Tomato is classified as a typical climacteric fruit with the onset of the rise in ethylene production at the beginning of the ripening process and the sharp increase in ethylene production at the peak of the ripening process (Paul et al., 2012).

In the first part

Conclusion

The findings in this study were first to describe that the relationship between the CIE a* value and cumulative ethylene production follows the sigmoid-type function during ripening not only at 25 °C but also at 12, 15, and 20 °C. However, the goodness of the proposed model varies not only with the storage temperature but also the sample usage. Further research to modify the sigmoid-type function needs to be conducted to improve the goodness of the proposed model at any storage temperature.

CRediT authorship contribution statement

Drupadi Ciptaningtyas: Conceptualization, Methodology, Data curation, Writing - original draft. Wakana Kagoshima: Methodology, Data curation. Rei Iida: Methodology, Writing - review & editing. Hitomi Umehara: Methodology, Writing - review & editing. Masafumi Johkan: Funding acquisition, Writing - review & editing. Nobutaka Nakamura: Methodology, Writing - review & editing. Takahiro Orikasa: Methodology, Software. Manasikan Thammawong: Methodology, Writing - review & editing. Takeo Shiina:

Acknowledgments

This research was supported by grants from the Project of the NARO Bio-oriented Technology Research Advancement Institution (the special scheme project on vitalizing management entities of agriculture, forestry and fisheries) and by JSPS KAKENHI Grant Number JP17H01499.

References (44)

  • M.H. Park et al.

    Changes in carotenoid and chlorophyll content of black tomatoes (Lycopersicone sculentum L.) during storage at various temperatures

    Saudi J. Biol. Sci.

    (2018)
  • M.H. Park et al.

    Reduced chilling injury and delayed fruit ripening in tomatoes with modified atmosphere and humidity packaging

    Sci. Hortic. (Amst.)

    (2018)
  • J. Pinheiro et al.

    Kinetics of changes in the physical quality parameters of fresh tomato fruits (Solanum lycopersicum, cv. ’Zinac’) during storage

    J. Food Eng.

    (2013)
  • J. Qin et al.

    Investigation of Raman chemical imaging for detection of lycopene changes in tomatoes during postharvest ripening

    J. Food Eng.

    (2011)
  • M.E. Saltveit

    Effect of ethylene on quality of fresh fruits and vegetables

    Postharvest Biol. Technol.

    (1999)
  • R.E. Schouten et al.

    Modelling quality attributes of truss tomatoes: linking colour and firmness maturity

    Postharvest Biol. Technol.

    (2007)
  • M. Sheahan et al.

    Food loss and waste in Sub-Saharan Africa: a critical review

    Food Pol.

    (2017)
  • L.M.M. Tijskens et al.

    Modelling colour of tomatoes during postharvest storage

    Postharvest Biol. Technol.

    (1994)
  • J. Trebolazabala et al.

    Portable Raman spectroscopy for an in-situ monitoring the ripening of tomato (Solanum lycopersicum) fruits

    Spectrochim. Acta, Part A

    (2017)
  • P. Wanitchang et al.

    Non-destructive maturity classification of mango based on physical, mechanical and optical properties

    J. Food Eng.

    (2011)
  • R.B.H. Wills et al.

    Use of 1-MCP to extend the time to ripen of green tomatoes and postharvest life of ripe tomatoes

    Postharvest Biol. Technol.

    (2002)
  • Q. Wu et al.

    Synergistic effect of abscisic acid and ethylene on color development in tomato (Solanum lycopersicum L.) fruit

    Sci. Hortic. (Amsterdam)

    (2018)
  • Cited by (0)

    View full text