Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In the present manuscript authors evaluated the effect of abiotic factors of the cultivation location has impacted, or not, the content of carotenoids, tocopherols and vitamin C in fresh tomato fruit, and how two different methods of processing tomato juice affected the stability of phytonutrients.

It was not until the abstract was consulted that the research topic of the manuscript was understood. In my opinion, there is potential for the title to align more closely with the content.

Abstract: the content is correct, there is a comparative resume of the results obtained in the experiment and some lines with the main conclusion. The final sentence of the abstract leaves questions open. ‘The content and stability of phytonutrients in pomace, a by-product of tomato juice processing, was also assessed’.Which phytonutrients? Which content, precisely? Which of these was stable?

Introduction: the content is correct and the main points are covered but there are few actual references since the most recent article is from 2016, 9 years of state of the art are missing and should be reflected in the introduction.

As stated in the final paragraph of the introduction, the objective of the study is to evaluate the impact of climatic and seasonal differences on the content of bioactive compounds in fresh fruit and processed juice. Tomato cultivation can have several harvests in a year, therefore, the utilisation of the term "season" to denote distinct productive years can be misleading. It may give rise that it refers to the spring and winter of the same year, rather than to successive years. It is recommended that the word 'seasons' be corrected.

Material and methods very complete, but I think there is a lack of references to the techniques used. As explained before, it is recommended that the word 'seasons' be corrected. The harvest date for each year should be specified, or at least the month. Better explanation of pomace, fruit and juice is needed.

Results and discussion: To improve readability, try to avoid long paragraphs and do not repeat explanation of results. Table headings should be revised. For example, Table 1 and 5 incorporate geographical locations, such as cities, rather than merely numerical data. Table 2 and 3, the text should be positioned at the summit of the table. The text at the bottom of the table is for providing statistical clarifications and abbreviations.

Does the bars in the graphics correspond to the standard error (SE) or the standard deviation (SD)?. This need to be incorporated into the figure caption. Abbreviations used in the graphs should be explained in the heading.

 ‘In the present work, the focus was on carotenoid compounds that are related to the quality, nutritional properties in freshly harvested tomatoes and their thermally processed juices’. What are the related carotenoids?

In general, it is difficult to follow the explanation of results. Sometimes it is not clear whether the results of the fruit, the juice or pomace are being presented. In this matter, it is recommendable to maintain order and structure all along the manuscript. The statement of the results must follow the same order in the sections.

Conclusion: well-structured, easy to read, summarize the results.

 

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This study primarily investigates the effects of climate variables on the content of tomato pigments, vitamin E, and vitamin C, as well as their responses to postharvest thermal treatments. It further examines the differences in the stability of carotenoids, tocopherols, and vitamin C during cold break (CBE) and hot break (HBE) processing of tomatoes grown under different climatic conditions. The research premise is reasonable and holds some practical significance for guiding production. However, several key issues remain in the manuscript:

 

1. Climate factors include temperature, precipitation, light, humidity, wind, and atmospheric composition. While temperature and rainfall can influence carotenoid formation, other factors such as light intensity, light quality, and diurnal temperature variation also play critical roles in the biosynthesis of plant phytochemicals. In this study, based on the “Meteorological parameters” table on page 4 and throughout the text, the authors only consider temperature and precipitation, neglecting key factors like light and diurnal temperature fluctuations. Moreover, the temperature difference between the two selected locations over two years is only about 1°C, and precipitation during the growing seasons is similar. The main differences lie in “Days in excess at 30°C during the growing season” and “Precipitation (mm) 3 weeks before harvest,” yet these differences are neither adequately reflected in the title, abstract, nor conclusion, and their impact is only briefly mentioned in part of the results.

Furthermore, regarding precipitation differences, the authors mention in section 2.2 that “Sufficient and optimal water supply of the stock was provided by the drip system during the growing season, depending on air temperature and precipitation,” suggesting that water impact can essentially be ignored.

2. The manuscript does not clarify whether greenhouse cultivation was used. Greenhouse and open-field cultivation differ significantly in environmental conditions (temperature, light, humidity), which directly affect the accumulation and stability of tomato carotenoids and other secondary metabolites. Additionally, information on the cultivated tomato varieties is not specified.
3. The title defines the study as examining the effect on “phytochemicals,” but only three compounds are analyzed: carotenoids, vitamin E, and vitamin C. In tomatoes, primary metabolites such as sugars and organic acids are also important phytochemicals with significant physiological and nutritional value but are not addressed in this work.
4. The authors emphasize that climate change affects the stability of phytochemicals in tomato fruits. While this is possible, the conclusion is speculative and not well supported by experimental analysis. Since they separated and identified different carotenoids and tocopherols, the authors should analyze which compounds increase or decrease in stability based on these data. Unfortunately, they did not sufficiently utilize these results and failed to provide substantive analysis, leaving this conclusion largely speculative.
5. The manuscript investigates three factors (two locations, two years, two processing methods), making it challenging to present results clearly. Many parts lack logical coherence, making some sections difficult to understand. Examples include:

(1) At the end of the second paragraph on page 7, it is stated, “As for tomato cultivated under opposite conditions of climate 1, the loss of carotenoids was higher in HBE,” but the following evidence shows “In 2018, the loss of 44–51% and 33–49% was recorded for juices from CBE and HBE respectively,” indicating higher loss in CBE. Moreover, results for climate condition 2 include two years, whereas climate 1 only shows 2018 data. 

(2) In the first paragraph of page 11, the authors write, “Since lycopene is the dominant carotenoid compound in tomato, it tended to change in a similar way to that of the total carotenoids. The same trend was also observed for other carotenoids such as ɣ-carotene, β-carotene, phytoene, and phytofluene,” but it is unclear what exactly the trend is. Subsequently, they claim, “The highest increase was 237% for β-carotene of juice and pomace from CBE of tomato cultivated under Climate 1, while a 200% increase was recorded for lutein in 2018 in juice and pomace prepared by HBE.” It is unclear what these increases are compared to, and which year the 237% corresponds to. Then, “On contrast, the sum of lutein content in juice and pomace was -19% and 0% with CBE and HBE respectively as compared to that of freshly harvested raw tomato in 2019 season when the precipitation 3 weeks before harvest...,” switching from β-carotene to lutein, yet using “On contrast” is confusing here. 

(3) Later in the last paragraph of page 11, the authors state, “In both seasons, the level of isomers and degraded products of carotenoids was greater in juice produced by HBE ...” but do not indicate the data source. 

(4) On the last paragraph of page 12, “The CBE of tomato cultivated under climate of location 2 yielded juice and pomace with lower tocopherol content as compared to that obtained with HBE (p<0.01). The opposite trend was observed in juice from tomato cultivated in location-1.” However, from Figure 5, results under climate 2 for CBL and CBM in two years do not show a trend opposite to climate 1.

6. The authors focus more on inter-year and inter-climate differences but barely consider the influence of the initial chemical composition of raw materials under different climate conditions. It is normal that higher initial content leads to higher loss rates.
7. Vitamin C results are questionable: the 2018 products show no vitamin C, while 2019 products contain substantial amounts, despite similar starting values, which reduces confidence in the data.
8. Throughout the results, climate 2 is consistently reported before climate 1. It would be more logical and conventional to follow a consistent sequence or clearly explain the order.
9. The manuscript uses overly complex and inconsistent abbreviations for groups, which are confusing for readers. Examples include “CBE-J, HBE-J, CBE-P, HBE-P”; “CBL, HBL, CBM, HBM”; and “CBL, HBL, CBP, HBP.”
10. Tables 2 and 3 report only year differences but have very different title formats, causing reader confusion.
11. The results section lacks statistical significance analysis; figures and tables do not include significance markers (such as lowercase letters, asterisks, or p-values).
12. The samples used in Figures 1 and 4 are not described by the authors. Moreover, peak assignments lack confirmation by standards, which requires further verification. Additionally, peaks 12 and 17 in Figure 1 exhibit incomplete peak shapes, poor separation, or tailing, likely affecting qualitative and quantitative accuracy.
13. Given that the study’s objective is to investigate the effects of “climate factors,” all figures in the manuscript present the two climate conditions in separate graphs, which does not facilitate rapid comparison between them for the readers.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

It is evident that the manuscript has undergone significant improvement. The authors have demonstrated a commendable ability to consolidate the reviewers' recommendations, resulting in a cohesive and well-organised document. In my estimation, the manuscript meets the necessary standards for publication in its current state.

Author Response

See attached file

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have made relatively comprehensive revisions and responses based on the review comments; however, some issues still require further improvement by the authors.

1. Since the group consensus acknowledges that climate factors are not limited to rainfall and temperature as mentioned in the manuscript, the title should explicitly refer to "rainfall and temperature" rather than broadly using "climate." Because this makes the title longer, remove the phrase "n content and response of."
2. Because the authors studied not only the components of the juice but also those of the pomace, the "Methods" section completely lacks any description regarding pomace. The authors need to supplement this.
3. Since the components studied in the title are limited to "carotenoids, tocopherols, and vitamin C," section "2.4. Analysis of bioactive compounds" should not continue to use the broad term "bioactive compounds," as this term is too general.
4. Regarding the incomplete peak shapes of peaks No. 12 and No. 17 in Figure 1, I do not deny the authors’ response, but we have encountered similar issues in our research. Although different components can currently be separated, strictly speaking, this analysis is not ideal and is likely caused by too high sample concentration or similar reasons. Normally, the peak top should not be flat but sharp.
5. Table headers should all be placed above the tables. In the manuscript, both Table 1 and Table 3 are placed after the tables, and even the header of Table 1 is located far away from Table 1;
6. The significance marks in Tables 2–4 should be placed at the upper right corner of the respective results.
7. The same indicator involves two years in the manuscript; the corresponding figures should be arranged as one large figure containing two sub-figures, not as two separate large figures.
8. The horizontal axes of the HPLC chromatograms in Figures 1 and 4 lack axis labels. "minutes" is a unit and cannot be used as an axis label alone.
9. Abbreviations should be defined with their full names the first time they appear in both the abstract and the main text, and only at their first occurrence in the main text thereafter. Therefore, it is unnecessary to repeat full names of corresponding abbreviations in figures and tables. Also, a separate "Abbreviations" section at the end of the manuscript is not required.
10. The sentence "Cultivation was carried out in two locations differing in climate variables." in the abstract can be deleted, as readers can easily understand this information later. Additionally, it is recommended to avoid using abbreviations like "Location-1" and "Location-2" in the main text; they may be used in figures.
11. No subsection "2.3" was found in the "2. Materials and Methods" section.
12. Some units are not consistent. For example, some are written as "(µg g-1 dry matter)" and others as "µg.g-1 dm." Also, are the authors sure they are using "dry matter"? Please carefully recheck. Is it appropriate to use "dry matter" for juice?
13. Is the expression "P<0.01-0-001" in Line 34 a standard and correct notation?
14. Large blank spaces appear multiple times in the manuscript, such as at Lines 135–142, 347–350, and 470–496. These issues indicate that the authors did not carefully check the generated PDF format before submission.

Author Response

See attached file

Author Response File: Author Response.pdf