Slightly Acidic Electrolyzed Water Improves the Postharvest Quality of Litchi Fruit by Regulating the Phenylpropane Pathway

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Editor!

The manuscript entitled "Slightly acidic electrolyzed water improves the postharvest quality of litchi fruit by regulating phenylpropane pathway by Xuanjing Jiang, Xiangzhi Lin, Yuzhao Lin, Yazhen Chen, Yihui Chen, and Hongbin Chen" presents results of the application of acidic electrolyzed water to extend the shelf life of litchi fruit.

The introduction part focuses on the paper, the materials and methods are introduced in detail, and the results and discussion are satisfactory. I only have one suggestion that the authors calculate correlations between total phenolics, flavonoids and PAL and CH4 activity. It appears that acidic, electrolysed water significantly affects phenolics and I believe that correlations would shed further light on this phenomenon.

 

Conclusions: I suggest to add future prospects for this study

 

 

Author Response

Comment 1: The introduction part focuses on the paper, the materials and methods are introduced in detail, and the results and discussion are satisfactory. I only have one suggestion that the authors calculate correlations between total phenolics, flavonoids and PAL and C4H activity. It appears that acidic electrolysed water significantly affects phenolics and I believe that correlations would shed further light on this phenomenon. Answer: Thanks for the reviewer’ suggestion. The correlations between total phenolics, flavonoids and PAL and C4H activities would provide deeper insights into our research. We have included a new figure in our paper, titled "Fig. 7. Analyses of the correlations among disease index, disease-resistance compounds, and disease-resistance enzyme activities of litchi fruit during storage." Comment 2: Conclusions: I suggest to add future prospects for this study. Answer: Thanks for the reviewer’ suggestion. In the conclusions section, we have added future prospects, stating: "Further research should delve into optimizing SAEW treatment conditions tailored for various litchi cultivars to maximize the preservation effects. Additionally, exploring the molecular mechanisms underlying the interactions between SAEW treatments and disease resistance in litchi fruits would provide valuable insights. Continuing this line of inquiry could lead to more effective, sustainable practices in the preservation and enhancement of fruit quality in the agricultural industry. "

Reviewer 2 Report

Comments and Suggestions for Authors

The authors reported on the Slightly acidic electrolyzed water improves the postharvest quality of litchi fruit by regulating phenylpropane pathway. This work provides some new information, however, there are major concerns:

1. with the data analysis approach, as it remains unclear what was done. The author’s experimental design is not well explained to the readers. This study consists of more than one experimental factor and multiple levels. What type of data analysis was conducted before Duncan’s Multiple Range test?
2. It would be expected that at minimum a Factorial-ANOVA or Two-way ANOVA is applied on the data generated. There would be impacts of main factors as well as the interaction effects, and this was not considered at all in the results presented. I would request that the authors consider the re-evaluation of their data.

• How many replicates was prepared per treatment?

Overall, this manuscript requires further editorial and technical revision. Herewith are general remarks to help improve this current revised article:

General:

• Please better use of paragraphs will significantly improve the introduction section. A single sentence cannot stand as a paragraph, please merge where appropriate.
• Please, where methods and measurements involve the use of standards and calibration curves, kindly provide information on the accuracy (R² value) of and the equation obtained?

 

Abstract:

• Please put the results into an accurate statistical or comparative context with values provided. I miss the clear statistical comparison of the outcomes based on the treatments and the control.
• Please rewrite the entire abstract for clarity, currently not adequate.

Introduction:

Overall, the section is well written, but Line 101-110 can better be articulated the aim and objectives of this study is repetitive. Please rewrite.

Materials and methods:

General: This section should be critically revised in its totality

1. Correct and complete references should be provided for all chemical reagents, and instruments used and software.
2. Consistency of unit formats should be cross-checked throughout the article.

Results

• The results were not well presented with appropriate statistical comparison of treatments or experimental factors.
• Avoid repetition and preemptive discussion in the results.

Figures – All figures can be created with colour for the online readership and black and white for print. Please revise accordingly. Legend is not self-explanatory. What are the error bars or deviations for the mean value?

Discussion should be aligned with the results in terms of the number of subsections.

There is a lack of depth in comparison of the authors’ results to existing literature.

Line 565-576: The details stated here were neither presented in the methodology section nor in the result. Authors should provide

The conclusion should be revised to include the following:

• Conclusion should remind the readers of the most important findings.
• What is the limitation of work?
• Please, based on their results, the authors should provide recommendations for future work.

 

Author Response

Comment 1: with the data analysis approach, as it remains unclear what was done. The author’s experimental design is not well explained to the readers. This study consists of more than one experimental factor and multiple levels. What type of data analysis was conducted before Duncan’s Multiple Range test?

It would be expected that at minimum a Factorial-ANOVA or Two-way ANOVA is applied on the data generated. There would be impacts of main factors as well as the interaction effects, and this was not considered at all in the results presented. I would request that the authors consider the re-evaluation of their data.

Answer: Thanks for the reviewer’ comment. In the Statistical Analysis section, we first performed a One-way ANOVA on the five treatments daily to determine if there were significant differences among the treatments. Subsequently, Duncan’s Multiple Range Test was applied for further analysis if significant differences were noted. The description in this section was kept concise, mainly based on similar studies typically characterized by succinct narratives, hence the details were not extensively elaborated. We have added the relevant information in the Statistical Analysis section.

Comment 2: How many replicates was prepared per treatment?

Answer: Thanks for the reviewer’ comment. Three replicates were prepared per treatment.

Comment 3: Please better use of paragraphs will significantly improve the introduction section. A single sentence cannot stand as a paragraph, please merge where appropriate.

Answer: We reviewed the introduction section and found no instances where a single sentence forms a paragraph.

Comment 4: Please, where methods and measurements involve the use of standards and calibration curves, kindly provide information on the accuracy (R2 value) of and the equation obtained?

Answer: Thanks for the reviewer’ comment. Upon reviewing papers in the same field, we have not found instances where calibration curves or the equation are placed in the methods section, nor is it appropriate to include them in the results section.

Comment 5:

Abstract:

Please put the results into an accurate statistical or comparative context with values provided. I miss the clear statistical comparison of the outcomes based on the treatments and the control.

Please rewrite the entire abstract for clarity, currently not adequate.

Answer: Thanks for the reviewer’ comment. In the abstract section, adding "p < 0.05" and "p < 0.01" further clarifies the enhancing effect of SAEW treatment on the pericarp disease resistance-related compounds and disease resistance enzymes in lychee fruit during the later storage period.

Comment 6:

Introduction:

Overall, the section is well written, but Line 101-110 can better be articulated the aim and objectives of this study is repetitive. Please rewrite.

Answer: Thanks for the reviewer’ comment. We have deleted and organized the repetitive content in Lines 101-108.

Comment 7:

Materials and methods:

General: This section should be critically revised in its totality

Correct and complete references should be provided for all chemical reagents, and instruments used and software.

Consistency of unit formats should be cross-checked throughout the article.

Answer: Thanks for the reviewer’ comment. Relevant information has been added to the Materials and Methods section.

Comment 8:

Results

The results were not well presented with appropriate statistical comparison of treatments or experimental factors.

Avoid repetition and preemptive discussion in the results.

Figures – All figures can be created with colour for the online readership and black and white for print. Please revise accordingly. Legend is not self-explanatory. What are the error bars or deviations for the mean value?

Answer: Thanks for the reviewer’ comment. We added “Fig. 7. Analyses of the correlations among disease index, disease-resistance compounds, and disease-resistance enzyme activities of litchi fruit during storage.” in our paper. We have removed repetition and preemptive discussion in the results. All figures have been created with colour. In the figures, data are presented as the mean ± standard error (n = 3). This has been explained in the Statistical Analysis section, hence it is not reiterated beneath the figures.

Comment 9:

Discussion should be aligned with the results in terms of the number of subsections.

There is a lack of depth in comparison of the authors’ results to existing literature.

Line 565-576: The details stated here were neither presented in the methodology section nor in the result. Authors should provide

Answer: Thanks for the reviewer’ comment. The results are divided into six sections; dividing the discussion into six parts as well would appear too fragmented. Current research on this topic is limited, and as the introduction provides a substantial overview, further comparisons are not extensively included in the discussion section. The content in lines 565-576 outlines our future experimental plans; due to its length, it was not included in the final conclusion section.

Comment 10:

The conclusion should be revised to include the following:

• Conclusion should remind the readers of the most important findings.
• What is the limitation of work?
• Please, based on their results, the authors should provide recommendations for future work.

Answer: Thanks for the reviewer’ comment. The limitation of our study is the recognition that specific SAEW treatment conditions are required for different litchi varieties. This requirement likely arises from variations in pericarp thickness and cracking patterns among varieties. Although these factors have not been comprehensively explored, a deeper understanding of them could substantially improve the effectiveness of SAEW in the preservation of litchi fruits. We have added recommendations for future work.

Reviewer 3 Report

Comments and Suggestions for Authors

Litchi fruits were treated with SAEW at different available chlorine concentrations (ACC: 10, 25, 50, and 75 mg/L) and stored at 25 °C for six days. The results indicated that SAEW with an ACC of 25 mg/L significantly improved postharvest quality, reduced disease incidence, and enhanced both pericarp appearance and nutrient content in the arils.

It is strongly recommended that the discussion include an interpretation of why 25 ppm (ACC of 25 mg/L) was the optimal dosage, including the potential negative effects of both lower and higher concentrations, by expanding the content of Sections 3.1 to 3.4.
The term "DEGs" as presented in lines 458 and 533 appears inconsistent or unclear. It is recommended that the authors clearly define what constitutes differentially expressed genes (DEGs) in this study and ensure consistent usage throughout the manuscript.
The comparison with Zhang et al. [32] is appreciated; however, the discussion would benefit from a broader contextualization beyond varietal differences. It is recommended that the authors expand the comparison by considering other factors that may influence treatment efficacy, such as differences in fruit physiology (e.g., respiration rate, enzymatic activity), storage conditions, or experimental design. Including studies on other fruits treated with SAEW could also broaden the relevance of the findings.

Author Response

Comment 1：It is strongly recommended that the discussion include an interpretation of why 25 ppm (ACC of 25 mg/L) was the optimal dosage, including the potential negative effects of both lower and higher concentrations, by expanding the content of Sections 3.1 to 3.4.

Answer: Thanks for the reviewer’ comment. This is indeed a good question, and we have attempted to explain it in our paper. (Lines 528-537)

Comment 2：The term "DEGs" as presented in lines 458 and 533 appears inconsistent or unclear. It is recommended that the authors clearly define what constitutes differentially expressed genes (DEGs) in this study and ensure consistent usage throughout the manuscript.

Answer: Thanks for the reviewer’ comment. The term 'DEGs' as presented in lines 458 and 533 should actually be 'DRE' (disease resistance enzymes). Thank you for your attentive correction. DRE includes enzymes such as phenylalanine ammonialyase, cinnamate-4-hydroxylase, 4-coumarate CoA ligase, cinnamyl alcohol dehydrogenase, peroxidase, polyphenol oxidase, chitinase, and β-1,3-glucanase.

Comment 3：The comparison with Zhang et al. [32] is appreciated; however, the discussion would benefit from a broader contextualization beyond varietal differences. It is recommended that the authors expand the comparison by considering other factors that may influence treatment efficacy, such as differences in fruit physiology (e.g., respiration rate, enzymatic activity), storage conditions, or experimental design. Including studies on other fruits treated with SAEW could also broaden the relevance of the findings.

Answer: Thanks for the reviewer’ comment. The questions you've raised are very meaningful and align with the areas we want to explore further. We hope that with additional data, we can further analyze why different lychee varieties affect the efficacy of SAEW, so as to better tailor the SAEW treatment conditions for different lychee varieties. Zhang et al. also authored another paper exploring the impacts of SAEW treatment on the physiology, quality, and storage properties of postharvest carambola. The corresponding author of this paper is the same as that of the current article. Due to the journal's requirements for a low self-citation rate, many papers from our research group are not readily citable. (Zhang, J.; Liu, Q.; Chen, X. et al. Slightly acidic electrolyzed water treatment improves the quality and storage properties of carambola fruit. Food Chem. X. 2023, 27, 100555.)

 

 

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Accept in present form.