Browning of ‘Empire’ and ‘Fuji’ Apples as Affected by Antioxidant Activities

Round 1

Reviewer 1 Report

The manuscript improved from the first version and most of the comments were addressed by the authors. However, some points should be further clarified:

1. Experimental design must be better detailed as reported in the comment referred to line 53-61.

→ Sub-samples of flesh and core tissues in both cultivars were sliced, immediately put into liquid nitrogen, and stored at –80°C for analyses of peroxidase (POX), polyphenol oxidase (PPO), and phenylalanine ammfonia-lyase (PAL) activity.

Thanks. Number of total apples should be declared in this section.

2. ANOVA analysis or multivariate data analysis could be considered not just variable by variable but also in a multivariate perspective, i.e. considering together the different variables measured.

→ The data analysis parts also were changed as you recommended.

Authors are still presenting individual models for separate interaction factors. Could they justify why no multiway ANOVA or multivariate data analysis was performed? Furthermore, could they change period with time in-between parenthesis (Individual models were conducted for separate interaction factors (No treatment, 1-MCP, and period))?

So concerns are still open in the data analysis procedure. As an example:

“In ‘Empire’ apples, L* values in flesh tissue in both untreated and 1-MCP-treated fruit increased until one month after air storage and then started to decline by the end of the storage period (P = 0.001; Figure 6A), with rising trend observed for a* (P < 0.001; Figure 6C) and b* (P <0.001; Figure 6E) values.”

This means that significant difference was observed between time 1 month and 3 and 5 months? A post-hoc test by LSD is declared but the results of the test are not straightly reported. Maybe lettering on Figures could help.

3. L53-61- Plant material and 1-MCP treatment: How many apples were treated used in total? The authors declared they sampled 5 apples for sampling point but from chambers containing which amount?

→ Approximately, 100 sample were contained and we randomly choose samples at different sampling points.

Please add this information in the text (in section: Plant material and 1-MCP treatment)

4. Did the authors follow a sampling plan considering the geometry of the chamber? The apples were separated in different chambers according to variety or treatment? Or they were stored in the same chamber in different positions? Did the authors check the performance of the storage chamber in its geometry?

→ This is not an experiment on CA storage. After 1-MCP treatment, apples were placed in different refrigerators during experiments that were not kept in the laboratory.

This is a good point, but we could agree that different refrigerators have different fan speed and performance. Could the authors state that this was considered and control?

For instance the declared air storage at 0.5ºC was not affected by any fluctuation? 0.5° ± X°C?

Author Response

Please see the attached file. The blue-color letters indicate responses to the reviewer's request.

Author Response File: Author Response.pdf

Reviewer 2 Report

Authors have addressed most of the comments however, I still have few concerns:

The statistical results should be added to the figures. Figures should be made such that they can understood without the text of results. Currently, they lack statistical information. In absence of mean separation presentation in figures, it is difficult to understand results.

The correlation data should be removed from conclusion and should be kept in results and discussion.

Statistical analysis (2.7) should contain clear information on when which model was run.

Author Response

Please see the attached file. The blue-color letters indicate responses to the reviewer's request.

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The present manuscript aims at the investigation of the variation of antioxidant enzymes and browning in late-harvested ‘Empire’ and ‘Fuji’ apples during the cold storage. It considered the effect of factors related  to the incidence of browning (such as cultivar, IEC, and the antioxidant enzyme)s with 1-MCP and storage time to minimize the storage disorder.

Even though I am not a native speaker, I would suggest the authors to ask support for a relevant English revision. In the manuscript (from the really beginning of the abstract) there are sentences that do not really express a meaning due to wrong sentence construction, conjunctions, misspelling, agreement between subject and verb and so on.

Experimental design must be better detailed as reported in the comment referred to line 53-61.

Result discussion is lacking, especially for browning and colour.

ANOVA analysis or multivariate data analysis could be considered not just variable by variable but also in a multivariate perspective, i.e. considering together the different variables measured.

The following parts were not completed according to the format: Author Contributions, Funding, Conflicts of Interest.

L30: Substitute developing countries with low and middle income country (LMIC)

L53-61- Plant material and 1-MCP treatment: How many apples were treated used in total? The authors declared they sampled 5 apples for sampling point but from chambers containing which amount? Did the authors follow a sampling plan considering the geometry of the chamber? The apples were separated in different chambers according to variety or treatment?  Or they were stored in the same chamber in different positions? Did the authors check the performance of the storage chamber in its geometry?

L 65-66: Temperature in °C, the unit is missing.

Reviewer 2 Report

Please see my edits attached to the file. The manuscript needs to be revised for grammar. The results and discussion part needs to be improved significantly. The stats should be added more clearly. Moreover, revise the result to ensure that insignificant differences are not presented as increasing or decreasing. A correlation analysis should be performed to validate the authors statement about IEC and browning or antioxidant activity.

Comments for author File: Comments.pdf