Review Reports - Characterization of Contact Pressure Distribution and Bruising Prediction of Apple under Compression Loading

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Abstract:

- Break down lengthy sentences into shorter, more digestible ones.

- Consider including specific numerical results or findings in the abstract.

Mention the correlation coefficient and the range of error rates obtained from the FE analysis.

Introduction:

- Clearly state the gap in knowledge or research question that the current study aims to address.

- Briefly mentioning the novelty or unique contribution of the current study.

- Emphasizing the use of pressure-sensitive film (PSF) technique combined with finite element (FE) analysis for more accurate bruise prediction, which may not have been extensively explored in previous literature.

Materials and Methods:

- Provide a detailed description of the apparatus used for compression testing, PSF measurements, and bruise analysis.

- Describe the selection criteria for apple samples, including cultivar, ripeness stage, and storage conditions.

- Provide information on sample size, handling procedures, and any pre-testing treatments.

- Outline the procedure for conducting compression tests, including the applied load range, contact point configuration, and duration of loading.

- Specify how the curvature radius of the contact point was maintained and its impact on bruise area.

- Explain the procedure for applying pressure-sensitive film (PSF) to the apple samples and recording pressure distribution. Include details on the scanning process, image analysis techniques, and factors such as temperature and humidity during testing.

Results and Discussion:

- Instead of vaguely discussing "the significance of observed trends," elaborate on how these trends contribute to understanding the mechanical behavior of apples.

- Add more on the specific biochemical and structural changes in apple tissue under compression loading.

- Discuss the possible reasons behind the uneven distribution, such as variations in tissue structure or surface roughness, and how these factors might influence bruise formation.

Conclusion:

- include the significance of the identified pressure thresholds (e.g., ≥0.10 MPa) in relation to bruise formation and their potential implications for understanding fruit biomechanics.

Comments on the Quality of English Language

Acceptable

Author Response

Dear Ms. Isabella Theodora Toth and Reviewer

Thank you for your letter and for the reviewer’s most perceptive comments concerning our manuscript (processes-2875761). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. According to their thoughtful suggestions for some incorrect or awkward expressions, we have studied comments carefully and have made correction. Especially, we are sorry for our poor English for some awkward expressions. Therefore, we have provided detailed explanations which we hope meet with approval. In this revision, we have responded to these suggestions point-by-point and all changes made to the text are in red so that they maybe easily identified. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:

A list of revisions follows.

Point 1: Abstract: Break down lengthy sentences into shorter, more digestible ones. Consider including specific numerical results or findings in the abstract. Mention the correlation coefficient and the range of error rates obtained from the FE analysis. Introduction: Clearly state the gap in knowledge or research question that the current study aims to address. Briefly mentioning the novelty or unique contribution of the current study. Emphasizing the use of pressure-sensitive film (PSF) technique combined with finite element (FE) analysis for more accurate bruise prediction, which may not have been extensively explored in previous literature.

Response 1: Thanks to the expert's careful reading, the full text has been carefully checked and revised, and the text changes have been marked using the "Track Changes" function inside word. As requested, we added relevant information at appropriate places in Abstract and Introduction for clarity.

Point 2: Materials and Methods: Provide a detailed description of the apparatus used for compression testing, PSF measurements, and bruise analysis. Describe the selection criteria for apple samples, including cultivar, ripeness stage, and storage conditions. Provide information on sample size, handling procedures, and any pre-testing treatments. Outline the procedure for conducting compression tests, including the applied load range, contact point configuration, and duration of loading. Specify how the curvature radius of the contact point was maintained and its impact on bruise area. Explain the procedure for applying pressure-sensitive film (PSF) to the apple samples and recording pressure distribution. Include details on the scanning process, image analysis techniques, and factors such as temperature and humidity during testing.

Response 2: Thanks to the expert's careful reading, the full text has been carefully checked and revised. As requested, we have added the relevant information in Section 2.2 and 2.3.

Point 3: Results and Discussion: Instead of vaguely discussing "the significance of observed trends," elaborate on how these trends contribute to understanding the mechanical behavior of apples. Add more on the specific biochemical and structural changes in apple tissue under compression loading. Discuss the possible reasons behind the uneven distribution, such as variations in tissue structure or surface roughness, and how these factors might influence bruise formation. Conclusion: include the significance of the identified pressure thresholds (e.g., ≥0.10 MPa) in relation to bruise formation and their potential implications for understanding fruit biomechanics.

Response 3: Thanks to the expert's careful reading, the full text has been carefully checked and revised. As requested, we have added the relevant information in Section 3.1, 3.2 and 4.

We have tried our best to revise and improve the manuscript and made great changes in the manuscript according to the reviewer’s good comments. And here we did not list some changes but marked in red in revised paper. We appreciate for reviewer and editor’s warm work earnestly, and hope that the corrections will meet with approval. Once again, thank you very much for your comments and suggestions. We look forward to your information about my revised papers and thank you for your good comments.

Best regards

Jiaping Wang

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Characterization of contact pressure distribution and bruising predication of apple under compression loading

In this submission titled “Characterization of contact pressure distribution and bruising predication of apple under compression loading” the authors have conducted a study on the pressure distribution characteristics of apple subjected to compressive loading. The relationship between pressure area and bruise area was represented by a equation with a good fit for lower loads while the same exceeded for loads greater than 90 N.

Following are the queries that need to be resolved before considering the paper for publication.

Major Points

1. In the introduction part the authors shall outline the importance of this present study. The authors shall discuss the various reasons for the damage of apples during static and dynamic loading.

2. A single line introduction on Aksufuji” cultivar apples can be added in the Materials section, In addition, how many apples were considered for the study? How were the material properties of the apples found? What does the term firmness refer to in biological sense? What is the unit for Water content in Table 1 ? (For example, Wt %).

3. The authors can mark the microcapsules in Figure 1, although they are explicit

4. In Page No. 4, Line No. 125, “So the loading region of apple samples was peeled back the skin completely and then soaked 4 h in 1.2 M NaHCO3 solution (pH = 7.1) for fully enzymatic browning.” shall be revised.

5. Is there any relationship between the changes in area pressure area and bruise area of apples to maintain a constant pressure difference?

6. In Page No. 6, Line No. 198, the sentence, “PSF scans …… “ is incomplete .

Can this method applied to other species also?

The paper may be accepted after minor revisions in the Journal Processes.

Comments on the Quality of English Language

Minor Points

1. In the first line of the abstract the word characteristics is spelt wrong. In the last sentence of the abstract “can not” shall be changed as cannot.

2. Keywords may be revised. For example compression may be changed as “compression loading”.

3. In Page No 2, Line Nos 78 – 80, “In view of this , ……… static contacts .” shall be revised.

4. In Page No 6, Line 203, Unit for area needs to be superscripted (mm²). Kindly check in other places also.

5. In Page 8, Line NO. 240, the phrase “can be used to accuracy assess apple bruise” can be replaced as “can be accurately used to assess apple bruise”.

Author Response

Dear Ms. Isabella Theodora Toth and Reviewer

A list of revisions follows.

Point 1: In the introduction part the authors shall outline the importance of this present study. The authors shall discuss the various reasons for the damage of apples during static and dynamic loading.

Point 2: A single line introduction on Aksufuji cultivar apples can be added in the Materials section, In addition, how many apples were considered for the study? How were the material properties of the apples found? What does the term firmness refer to in biological sense? What is the unit for Water content in Table 1 ? (For example, Wt %)

Response 2:

Thanks to the expert's careful reading, the full text has been carefully checked and revised. As requested, we have added the relevant information in Section 2.1 and 2.2.

The material properties of apples are discovered through a combination of methods and approaches.

Fruit hardness refers to the strength of the pulp's ability to resist pressure, but also an important indicator of fruit maturity and storage quality. Specifically, fruit hardness refers to the pressure that the fruit unit area can withstand, that is, the ability of the fruit surface unit area to resist the external force pressed into. In the process of fruit maturation and aging, the pectin material between the pulp cells will be degraded, resulting in the pulp becoming flaccid and the hardness gradually decreasing. Therefore, through the determination of fruit hardness, we can understand the degree of maturity of the fruit, quality change characteristics and storage performance.

“%” is the unit of water content which has been added Table 1.

Point 3: In Page No. 4, Line No. 125, “So the loading region of apple samples was peeled back the skin completely and then soaked 4 h in 1.2 M NaHCO₃ solution (pH = 7.1) for fully enzymatic browning.” shall be revised.

Response 3: Thanks to the expert's careful reading, we have scrutinized and revised the specified locations as required.

Point 4: Is there any relationship between the changes in area pressure area and bruise area of apples to maintain a constant pressure difference?

Response 4: Under a constant pressure difference, the changes in contact area and bruise area will depend on the magnitude of the force, the duration of force application, and the mechanical properties of the apple's tissue. It is important to note that apples have different mechanical properties, such as hardness, elasticity, and toughness, which can affect their resistance to external forces and the resulting deformation and bruising. Therefore, the relationship between contact area and bruise area under a constant pressure difference may vary depending on the specific characteristics of the apple being tested.

Point 5: In Page No. 6, Line No. 198, the sentence, “PSF scans …… ” is incomplete . Can this method applied to other species also?

Response 5: Thanks to the expert's careful reading, we have scrutinized and revised the specified locations as required. A reading of the literature shows that this method can be applied to other agricultural products.

Point 6: Comments on the Quality of English Language Minor Points (1) In the first line of the abstract the word characteristics is spelt wrong. In the last sentence of the abstract “can not” shall be changed as cannot. (2) Keywords may be revised. For example compression may be changed as “compression loading”. (3) In Page No 2, Line Nos 78 – 80, “In view of this , ……… static contacts .“ shall be revised. (4) In Page No 6, Line 203, Unit for area needs to be superscripted (mm²). Kindly check in other places also. (5) In Page 8, Line NO. 240, the phrase “can be used to accuracy assess apple bruise“ can be replaced as “can be accurately used to assess apple bruise“.

Response 6: Thanks to the expert's careful reading, and we have scrutinized and revised the entire text according to the suggestions.

Best regards

Jiaping Wang

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The publication discusses the pressure distribution of apples subjected to a compressive load in combination with measurements of the apple's rebound using the pressure-sensitive foil (PSF) technique. The publication presents the results of experimental research and numerical simulations. It was noted, among other things, that the relationship between the pressure area and the contusion area can be represented by a linear equation. It was reported that for a load of 80N the error between simulation and experiment does not exceed 7.89%. In turn, above the load of 90N, it was noted that the linear elastic FE model did not allow for a satisfactory prediction of the accuracy of the simulation results with the experiment. The work is interesting and has a scientific and utilitarian nature.

I have a few comments/questions of an editorial and technical nature:

1. How many samples/apples were tested for a single series?

2. Was a specific experiment planning method used before preparing the research?

3. Was an optimization method used when developing a series of tests in relation to the output parameter.

4. I recommend graphical uniformity of charts in editing, e.g. in Figures 6 and 7, in my opinion, the chart areas and font sizes on the axes and their descriptions should be identical.

5. Why were 69600 finite elements used? Has there been any convergence between the accuracy of the results and the selected number of finite elements?

6. When designing the 3D model, did the porosity of the apple structure, the seed basket, seed cells, etc. take into account? Did the 3D model have a homogeneous or heterogeneous structure?

7. The selected literature contains very few items older than 2018. I encourage you to expand the literature introduction and the literature list with new, current titles.

Author Response

Dear Ms. Isabella Theodora Toth and Reviewer

A list of revisions follows.

Point 1: How many samples/apples were tested for a single series?

Response 1: 100 samples of Aksufuji apples were taken for each level test, Each level test was repeated 10 times. We have added the relevant information in Section 2.2.

Point 2: Was a specific experiment planning method used before preparing the research? Was an optimization method used when developing a series of tests in relation to the output parameter.

Response 2: Prior to the preparation of the study, the critical values of yield stress in the flesh of red Fuji apples and the maximum contact stress in apples under compression were obtained from the literature, from which pre-tests were developed and carried out to determine the parameters relevant for setting up the formal tests. The optimization method using boundary value analysis focuses on the boundary values of the input parameters, as many errors occur in the boundary conditions. By testing the boundary values, potential problems can be more easily identified.

Point 3: I recommend graphical uniformity of charts in editing, e.g. in Figures 6 and 7, in my opinion, the chart areas and font sizes on the axes and their descriptions should be identical.

Response 3: Thanks to the expert's careful reading, we have scrutinized and revised the specified locations as required.

Point 4: Why were 69600 finite elements used? Has there been any convergence between the accuracy of the results and the selected number of finite elements? When designing the 3D model, did the porosity of the apple structure, the seed basket, seed cells, etc. take into account? Did the 3D model have a homogeneous or heterogeneous structure?

Response 4: The linear cell type (linear) is used for free meshing, and the maximum boundary size of the mesh is set to be 2 mm in order to satisfy the calculation speed and solution accuracy, and a total of 69600 grid cells are generated. There is some convergence between the accuracy of the results and the number of finite elements selected. In designing the 3D model, the apple material is assumed to be an isotropic linear elastomer.

Point 5: The selected literature contains very few items older than 2018. I encourage you to expand the literature introduction and the literature list with new, current titles.

Response 5: Thanks to the expert's careful reading, we have scrutinized and revised the introduction and references.

Best regards

Jiaping Wang

Author Response File: Author Response.docx