Comparative Analyses of Ripening, Texture Properties and Cell Wall Composition in Three Tropical Fruits Treated with 1-Methylcyclopropene during Cold Storage

Round 1

Reviewer 1 Report

why same concentration( 1-MCP at 1.0 μL L−1 for 20 h) were applied for all three fruits? introduction and discussion can be improved. you may refer to the following relevant literature;

1)Characterization of Southeast Asia mangoes (Mangifera indica L) according to their physicochemical attributesScientia Horticulturae 243, 189-196, 2019.

2)_Postharvest profile of a Solo variety ‘Frangi’during ripening at ambient temperature, MK Ong, CF Forney, PG Alderson, A Ali, Scientia Horticulturae 160, 12-19, 2013.

3) Storage behaviour and quality responses of mango (Mangifera indica L.) fruit treated with chitosan and gum arabic coatings during cold storage conditions G Khaliq, MTM Mohamed, P Ding, HM Ghazali, A AsgarInternational Food Research Journal 23 (5), 141-148, 2016.

Author Response

Dear reviewer:

Thank you so much for your comments concerning our manuscript. Those comments are all valuable and very helpful for revising and improving our paper.

We submit here the revised manuscript as well as our responses. All changes have been marked in red in the revised manuscript, and response are listed below in blue color according to your comments.

Response: Thank you very much. In the early stage, our research group had conducted different concentration of 1-MCP treatment on mango, banana and papaya, and preliminarily found that 1-MCP of 1UL. L^-1 seemed to have fresh-keeping effects on sensory quality of three types of fruits, but no detailed measurement has been made on internal qualities and softening indicators. Then we selected the same concentration (1UL. L^-1) to do deep study, it was found that the physiology, softening, and quality responses of the three types of fruits treated with the same 1-MCP were significantly different, which is also the discovery and innovation of this article.

   Additionally, we have studied the references you suggested, they are very helpful for us understanding the postharvest traits of mango and papaya, and we cite the references in ‘Introduction’ and ‘Discussin’ sections of manusctipt.

Thank you very much!

Wen Li

Hainan university

Author Response File: Author Response.docx

Reviewer 2 Report

It is a very interesting study that shows how 1-MCP affects the postharvest behavior of 3 species: banana, mango, and papaya, emphasizing the softening process and the related enzymatic activity. Although 1-MCP has already been studied in these species, the authors mention that in the varieties used there is a lack of knowledge about the role of this retardant. Therefore, I consider that the results are very valuable. The manuscript is well-written and its results are well-discussed. My main suggestion is to review the statistics, I think that it should be focused on comparing the application or not of 1-MCP in each species, and not comparing between species. some additional suggestions are included directly in the pdf.

Comments for author File: Comments.pdf

Author Response

Dear reviewer:

Thank you so much for your comments concerning our manuscript. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches.

We submit here the revised manuscript as well as our point-by-point responses. All changes have been marked in red in the revised manuscript, and response are listed below in blue color according to your comments.

Response: thank you very much for your careful revision on our manuscript. We have revised every place which you have pointed in PDF, and marked them with red color, and we have added the relevant references which you suggested.

Thank you again. 

 Wen Li

Hainan University

Author Response File: Author Response.docx

Reviewer 3 Report

Dear Authors,

The manuscript Horticulturae-2115566, entitled "Comparative analyses of ripening, texture properties and cell wall composition in three tropical fruits treated with 1-methyl-3 cyclopropene during cold storage" has been thoroughly reviewed. It is original in its academic purposes and writing. There are some comments that can be found below.

1. The English writing is good and well organised. However, the writing format must be checked throughout the manuscript.

1.1 A consistent style must be used between American and British styles (such as colour (Line 190) vs color (Line 192).

1.2 Check the unit formats on the Y-axes of Figure 1.

1.3 Check the power of numbers in the units (such as Line 17, on the Y-axes of Figure 3 and 4.

1.4 Check other misformats (such as ‘spp.’ (Line 31), or AAA group (Line 72), or spelling errors (such as Line 294).

2. In the Abstract, Line 15-16, there has been researched on working with 1-MCP on these tropical fruits. What kinds of responses are still unknown that would have been mentioned in this study?

3. In the keywords, some are directly imitated by the words in the title and abstract. Some others, such as ethylene-responsive inhibitor, the scientific names of banana, mango, and papaya would be considered.

4. In the Introduction,

4.1 More information about ethylene regulating fruit softening and the related enzymes, because this study used 1-MCP, that an effective ethylene-responsive inhibitor.

4.2 Line 47-48, reference No. [8] is not relevant to support the sentence. Chen et al. (2022) worked only on the softening of bananas.

5. In the Materials and Methods, Line 80, How big was each fruit? Detail the average weight of each fruit.

6. In the Results,

6.1 Correct the units on the Y-axes of Figure 1

6.2 Correct the units on the Y-axes of Figure 3 and 4 (the power of numbers)

7. In the Discussion,

7.1 Line 325-339, for softening-related enzymes, PG and CX, please discuss more on the responses of this enzyme to ethylene, both in terms of gene expression and enzyme assays. Are both enzymes induced by ethylene? Are they, in other words, ethylene-dependent gene expression?

7.2  Line 325-339, The softening values in Figure 2C of mango fruit were not related to the PG and Cx activities in Figure 4? All tree fruit softening was reduced by 1-MCP applications, but for mango, the PG and CX levels between untreated control and 1-MCP-treated fruit were not different throughout storage. Please discuss.

Author Response

Dear reviewer:

Thank you so much for your comments concerning our manuscript. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches.

We submit here the revised manuscript as well as our point-by-point responses. All changes have been marked in red in the revised manuscript, and response are listed below in blue color according to the comments.

Reviewer 3

Dear Authors,

The manuscript Horticulturae-2115566, entitled "Comparative analyses of ripening, texture properties and cell wall composition in three tropical fruits treated with 1-methyl-3 cyclopropene during cold storage" has been thoroughly reviewed. It is original in its academic purposes and writing. There are some comments that can be found below.

1. The English writing is good and well organised. However, the writing format must be checked throughout the manuscript.
   • A consistent style must be used between American and British styles (such as colour (Line 190) vs color (Line 192).

Response: Thank you. It is changed.

• Check the unit formats on the Y-axes of Figure 1.

Response: Thank you, the unit formats on the Y-axes of Figure 1 is changed.

• Check the power of numbers in the units (such as Line 17, on the Y-axes of Figure 3 and 4.

Response: Thank you. They are changed.

      Figure 3                                  Figure 4

• Check other misformats (such as ‘spp.’ (Line 31), or AAA group (Line 72), or spelling errors (such as Line 294).

Response: Thank you.They are changed.

2. In the Abstract, Line 15-16, there has been researched on working with 1-MCP on these tropical fruits. What kinds of responses are still unknown that would have been mentioned in this study?

Response: Thank you. ‘its effects on ripening process, including ethylene production and softening of banana, mango, and papaya are still not very clear’ was added.

3. In the keywords, some are directly imitated by the words in the title and abstract. Some others, such as ethylene-responsive inhibitor, the scientific names of banana, mango, and papaya would be considered.

Response: Thank you. ‘1-Methylcyclopropene; banana; mango; papaya; ripening; texture’ is changed to ‘ethylene-responsive inhibitor; tropical fruits; ripening and softening; pulp cell structure’.

4. In the Introduction,
   • More information about ethylene regulating fruit softening and the related enzymes, because this study used 1-MCP, that an effective ethylene-responsive inhibitor.

Response: Thank you. It is modified.

• Line 47-48, reference No. [8] is not relevant to support the sentence. Chen et al. (2022) worked only on the softening of bananas.

Response: Thank you. The sentence is changed to ‘Among various cell wall degrading enzymes, PG and CX are thought to be responsible for softening of banana fruit’.

5. In the Materials and Methods, Line 80, How big was each fruit? Detail the average weight of each fruit.

Response: Thank you. The weight of fruits is added in ‘Plant materials’ section.

6. In the Results,

6.1 Correct the units on the Y-axes of Figure 1

Response: Thank you. It is changed.

6.2 Correct the units on the Y-axes of Figure 3 and 4 (the power of numbers)

Response: Thank you. It is changed.

7. In the Discussion,

7.1 Line 325-339, for softening-related enzymes, PG and CX, please discuss more on the responses of this enzyme to ethylene, both in terms of gene expression and enzyme assays. Are both enzymes induced by ethylene? Are they, in other words, ethylene-dependent gene expression?

7.2  Line 325-339, The softening values in Figure 2C of mango fruit were not related to the PG and Cx activities in Figure 4? All tree fruit softening was reduced by 1-MCP applications, but for mango, the PG and CX levels between untreated control and 1-MCP-treated fruit were not different throughout storage. Please discuss.

Response: Thank you very much. It is a very interesting phenomenon. According to the references below, we discuss the possilble reason and add the paragraph ‘It is worth noting that the firmness value of mango fruit treated with 1-MCP was significantly higher than that of the control fruit (Fig. 2), indicating that 1-MCP inhibits the softening of mango fruit, but there was no significant difference in the changes of PG and CX activities between the treated fruit and the control fruit. It is speculated that some other cell wall degrading enzymes, such as pectin methylesterase (PME), β-galactosidase (β-Gal) or some key genes, such as expansin gene, MiExpA1 play a key regulatory role in softening of mango fruit’ in ‘discussion’ section. Moreover，we think it is necessary to conduct more in-depth research on mango fruit softening from the aspects of gene expression and transcriptional regulation in the future. Thank you again!

1. Liu, S.M.; Huang, H.;Huber, G.J.; Pan, Y.G.;Shi, X.Q.; Zhang, Z.K. Delay ofripening and softening in ‘Guifei’ mango fruit by postharvest application of melatonin.Postharvest Biol. Technol. 2020, 163,111136. 
2. Sane,V.A.; Chourasia, A.; Nath, P. Softening in mango (Mangifera indica cv. Dashehari) is correlated with the expression of an early ethylene responsive, ripening related expansin gene, MiExpA1.Postharvest Biol. Technol. 2005, 38, 223-230.

Thank you again!

Wen Li

Hainan University

Wen Li

Hainan University

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Below two references are highly relevant to the article for improvement.

Effect of chitosan coatings on the physicochemical characteristics of Eksotika II papaya ( Carica papaya L.) fruit during cold storage .Food Chemistry 124 (2), 620-626, 2011.

Effect of a novel edible composite coating based on gum arabic and chitosan on biochemical and physiological responses of banana fruits during cold storageJournal of Agricultural and Food Chemistry 59 (10), 5474-5482

Author Response

Dear reviewer:

Thank you very much for your suggestion. We learn and cite the two references in ‘Introduction’ section.

16. Ali, A.;Muhammad,M.T.M.;, Sijam,; Siddiqui, Y. Effect of chitosan coatings on the physicochemical characteristics of Eksotika II papaya (Carica papaya L.) fruit during cold storage. Food Chem. 2011,124, 620–626.
17. Maqbool,; Ali, A.; Alderson，P.G.; Zahid,N.; Siddiqui, Y. Effect of a Novel Edible Composite Coating Based on Gum Arabic and Chitosan on Biochemical and Physiological Responses of Banana Fruits during Cold Storage. J. Agric. Food Chem. 2011, 59, 5474–5482.

Author Response File: Author Response.docx