Preparation, Characterization, and Release Kinetics of Zanthoxylum bungeanum Leaf Polyphenol–Chitosan Films
Round 1
Reviewer 1 Report
The paper is interesting and most of the experimental data are obtained and discussed correctly. However there are some aspect which require significant improvement:
The preparation of films and characterization extracts are not described well enough. First the authors must explain why they choose to compare the extract with tannic acid.
I think that a through characterization of the extract by HPLC method in order to assess the influence of particular compounds in the protection process.
“Zanthoxylum bungeanum leaf Polyphenol (ZMP) is a by-product of the Zanthoxylum bungeanum industry, with high yields and low costs” – some detail regarding this waste are needed not only the reference.
“Forin reagent” is not a correct name and is not mentioned in the material and method part.
“into three groups (n = 15): unprepared control (CK), C-film, ZMP/C-film. Put strawberry into 4 L
polystyrene containers, cover the container port with ZMP/C- film” – The container dimensions are needed. How 15 strawberries are protected in 4 L container sealed with prepared film? What are the dimension of the film? How the vitamin C is measured? And on what sample? Also how the weight loos was measured? The container is unsealed and some fruits are extracted and measured or is another procedure. Please specify. In my understanding the films are used merely as a lid for containers. In another studies the fruit are wrapped in the film or the fruit is immersed in the solution to form a protective layer.
What is the relevance of polyphenols release in solution if the fruits are not even in contact with the film and the preservation process are performed in gaseous phase?
Considering this if the authors are not able to provide better explanations for their experiments the paper cannot be published in the current form.
The English must be improved
Author Response
Dear Reviewer,
We have studied the valuable comments carefully and tried our best to revise the manuscript. The point to point responds the reviewer’s comments are listed as following:
Comment 1: The preparation of films and characterization extracts are not described well enough. First the authors must explain why they choose to compare the extract with tannic acid.
Response: Thanks for the reviewer’s suggestions. The preparation of films was revised. The detailed revisions can be found in Line 113-124 in our revised manuscript, and marked in red font. The characterization of Zanthoxylum bungeanum leaf polyphenol (ZMP) has been determined. The method and result of ZMP composition analysis have been added to “2.2.1. Preparation of ZMP”, “2.2.2. Purification and analysis of ZMP” and “3.1. ZMP composition analysis” of the revised manuscript, and marked in red font.
Comment 2: I think that a through characterization of the extract by HPLC method in order to assess the influence of particular compounds in the protection process
Response: Thanks for the reviewer’s kind advice. Previously, the ingredients have been studied and analyzed. These data have been supplemented in the revised manuscript, and marked in red font.
Comment 3: “Zanthoxylum bungeanum leaf Polyphenol (ZMP) is a by-product of the Zanthoxylum bungeanum industry, with high yields and low costs” – some detail regarding this waste are needed not only the reference.
Response: Thanks for the reviewer’s kind suggestions. In agricultural production, most of ZMP are discarded, even burned or buried, causing great waste. These descriptions have been added to in Line 53-56 of the revised manuscript, and marked in red font.
Comment 4: “Forin reagent” is not a correct name and is not mentioned in the material and method part.
Response: Thanks for the reviewer’s suggestions. “Forin reagent” has been modified “Folin–Ciocalteu reagent”. Reagent information is added to Line 78 of “2.1. Materials and reagents”. The corrected details have been marked in red font.
Comment 5: “into three groups (n = 15): unprepared control (CK), C-film, ZMP/C-film. Put strawberry into 4 L polystyrene containers, cover the container port with ZMP/C- film” – The container dimensions are needed. How 15 strawberries are protected in 4 L container sealed with prepared film? What are the dimension of the film? How the vitamin C is measured? And on what sample? Also how the weight loos was measured? The container is unsealed and some fruits are extracted and measured or is another procedure. Please specify. In my understanding the films are used merely as a lid for containers. In another studies the fruit are wrapped in the film or the fruit is immersed in the solution to form a protective layer.
Response: Thanks for the reviewer’s kind advice. The fruits with consistent colors, size, weight and no apparent damage were selected. The samples were divided into three groups, namely a blank control group (CK), C-film group and ZMP/C-film group. The samples were weighted at room temperature. Except for the CK, the strawberries were placed in polystyrene containers containing eight fruits each and covered with a 20 cm × 20 cm ZMP/C- film or C-film, respectively. Unpackaged and packaged samples were analyzed at 25 ℃ for weight loss rate, vitamin C content (VC) and appearance at 0, 1, 2, 3, 4, 5, 6, 7 d during storage. The experiment method of strawberry preservation has been modified in revised manuscript (see “2.2.8. Practical application of film on fresh strawberry fruit”).
The weight loss rate was measured by the weight method. The content of VC was measured by a titrimetric method, based on reduction of 2,6-dicholorophenolindophenol. The determination method of the weight loss rate and VC content has been supplemented in revised manuscript. The revised content and marked in red font (see “2.2.8. Practical application of film on fresh strawberry fruit”).
Comment 6: What is the relevance of polyphenols release in solution if the fruits are not even in contact with the film and the preservation process are performed in gaseous phase?
Response: We sincerely appreciate the valuable feedback from the reviewers. In our study, the polyphenol release was investigated in food simulated solution. The strawberry was used to the preservation application of film. The relevance of polyphenols release and the preservation of strawberry has not been studied. But we think the reviewer’s suggestion is very important, we need to consider the system consistency of polyphenol release of ZMP/C-film and its preservation application in our future work. About the polyphenols release of ZMP/C-film, we found the polyphenols can be release in three different food simulation systems in water, acetic acid and ethanol. We speculated that the polystyrene containers covered with the film can form a water vapor microenvironment to reduce water loss of strawberries and induce the release of polyphenols of ZMP, thereby reducing oxidative spoilage of strawberries.
Comment 7: The English must be improved
Response: Thanks for the reviewer’s kind suggestion. We tried our best to improve the English of the entire manuscript, and the revised content has been marked in red.
We tried our best to improve the manuscript and made some changes in the manuscript. Should you have any questions, please contact us without hesitate.
Once again, thank you very much for your comments and suggestions.
Have a good day!
Sincerely yours,
Dr. Bianfang Hu
Department of biological science and technology, Jinzhong University, Yuchi 030619, P.R.C
E-mail: [email protected]
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript intitled "Preparation, characterization and release kinetics of Zanthoxy- 2 lum bungeanum Leaf Polyphenol - Chitosan films" is an original research paper with a novel chitosan-based coating with control release of polyphenols applied to strawberries preservation.
The study is very interested but there are much points to revised before further evaluation.
Abstract
1. It must be revised and become more attractive for the readers
Introduction
It must be revised. The author's must add a paragraph before the last one referred to the application of chitosan based coatings in fruit preservation. Here are some relevant references which must be added in this paragraph. https://doi.org/10.1016/j.fochx.2023.100575, https://doi.org/10.21967/jbb.v4i1.189, https://doi.org/10.3390/gels8120823
Also, the last paragraph of the introduction must contain the innovation points of this work.
Materials and Methods
Figure 1: To confirm transparency is better to use a white page or a page with text
line 137: Add the instrumentation used for the tensile properties measurements
the text style and size inside all equation must be in the form of the journal see the guide for authors
The obtained plots of kinetics are the average of at least three experiments? Add deviation in the plot.
The obtained plots of kinetics are the average of at least three experiments? Add deviation in the plot
The obtained plots of kinetics are the average of at least three experiments? Add deviation in the plot
Author Response
Dear Reviewer,
We have studied the valuable comments carefully, tried our best to revise the manuscript. The point to point responds the reviewer’s comments are listed as following:
Comment 1: Abstract：It must be revised and become more attractive for the readers
Response: Thanks for the reviewer’s kind suggestion. According to the opinions of the reviewers, we have condensed and revised the abstract of the manuscript again. The modified section has been marked in red font.
Comment 2: Introduction：It must be revised. The author's must add a paragraph before the last one referred to the application of chitosan-based coatings in fruit preservation. Here are some relevant references which must be added in this paragraph. https://doi.org/10.1016/j.fochx.2023.100575, https://doi.org/10.21967/jbb.v4i1.189, https://doi.org/10.3390/gels8120823
Response: Thanks for the editors’ kind advice. We have added a paragraph referred to the application of chitosan-based coating in fruit preservation in Line 36-43. The relevant references were added in this paragraph, including “https://doi.org/10.1016/j.fochx.2023.100575”, “ https://doi.org/10.21967/jbb.v4i1.189” and https://doi.org/10.3390/gels8120823.
Comment 3: Also, the last paragraph of the introduction must contain the innovation points of this work.
Response: Thanks for the reviewer’s kind suggestion. We have revised the last paragraph of the introduction, and highlighting the innovation points of this study. The revised content was marked in red font.
Comment 4: Materials and Methods：Figure 1: To confirm transparency is better to use a white page or a page with text.
Response: Thanks for the reviewer’s kind suggestions. We attempted to take photos with a white background and solved the problem of reflection, but the photo effect was weakened. The Figure 1 was deleted in the revised manuscript. This will not influence the content and framework of the paper. Comment 5: line 137: Add the instrumentation used for the tensile properties measurements.
Response: Thanks for the reviewer’s kind suggestion. We have added the instrumentation (CMT4204 Universal Tension Machine) in the method of mechanical properties in Lin 150.
Comment 6: the text style and size inside all equation must be in the form of the journal see the guide for authors.
Response: Thanks for the reviewer’s kind suggestion. We have revised the text style and size inside all equation according to the guide for authors.
Comment 7: The obtained plots of kinetics are the average of at least three experiments? Add deviation in the plot.
Response: Thanks for the reviewer’s kind suggestion. The deviations were added in the plot of ZMP release data fitted to various kinetic models.
We tried our best to improve the manuscript and made some changes in the manuscript. Should you have any questions, please contact us without hesitate.
Once again, thank you very much for your comments and suggestions.
Have a good day!
Sincerely yours,
Dr. Bianfang Hu
Department of biological science and technology, Jinzhong University, Yuchi 030619, P.R.C
E-mail: [email protected]
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The paper is considerably improved. However some aspect need to be clarified:
1. After the preparation of ZMP the author proceed to extract purification. Why? How is made? (the simply mentioning the polyamide stationary phase is not enough)
2. “The composition of ZMP 100 was analyzed by HPLC on a Symmetry C18 column” – which product was analyzed before or after purification of ZMP. “2.2.2. Purification and analysis of ZMP” this paragraph must be rewritten. “With a ZMP purification 104 injection volume of 1 μL” for HPLC the injection volume is very low. Usually is from 5 to 20 μL.
3. It is still unclear: each piece of fruit was wrapped in “20 cm × 20 cm ZMP/C- film or C-film, respectively.” ??? or what?? – Please clarify
4. “Figure 5 FXRD patterns of C-film, TA/C-film and ZMP/C-film” – please perform the designation of XRD patterns.
5. “Kinetics of polyphenol release” – wat is the role of this kinetic study. The polyphenols are release into the fruits or what. What is the relevance?
2.2.2. Purification and analysis of ZMP” this paragraph must be rewritten due to poor English
Author Response
Dear reviewer,
We have studied the valuable comments carefully, and tried our best to revise the manuscript. The point to point responds the reviewer’s comments are listed as following:
Comment 1: After the preparation of ZMP the author proceed to extract purification. Why? How is made? (the simply mentioning the polyamide stationary phase is not enough)
Response: Thanks for the reviewer’s suggestions. The cure extract of ZMP contained complex components. The difficulty of separating and analyzing ZMP composition by HPLC has been increased. In addition, the extract purification was also a process of concentration enrichment. The 25 mL ZMP crude extract passed down the glass column (50 × 1.5 cm) wet-packed with polyamide at a fixed flow rate of 1.5 BV/h. The effluent was gathered and monitored at 0.5 BV intervals. After equilibrium of the distribution system, the column was in turn eluted with ddH2O and 75% (v/v) ethanol solutions, and the resulted were monitored and analyzed. The purified ZMP was eventually obtained for further the composition analysis. The descriptions of cure extract purification of ZMP were revised in “2.2.2. Purification and analysis of ZMP”, and marked in red font.
Comment 2: “The composition of ZMP was analyzed by HPLC on a Symmetry C18 column” – which product was analyzed before or after purification of ZMP. “2.2.2. Purification and analysis of ZMP” this paragraph must be rewritten. “With a ZMP purification injection volume of 1 μL” for HPLC the injection volume is very low. Usually is from 5 to 20 μL
Response: Thanks for the reviewer’s kind advice. The purified ZMP composition was analyzed. We have rewritten the paragraph of “2.2.2. Purification and analysis of ZMP”. About the injection volume, we are very sorry for the mistake caused by our carelessness. We have corrected the injection volume to 5 μL. The corrected content was marked in red font.
Comment 3: It is still unclear: each piece of fruit was wrapped in “20 cm × 20 cm ZMP/C-film or C-film, respectively.” ??? or what?? – Please clarify
Response: Thanks for the reviewer’s kind suggestions. Except for the CK, each treatment group consists of eight strawberries placed in poly-styrene containers. 20 cm × 20 cm ZMP/C- film or C-film was used to cover the con-tainer mouth for strawberry preservation. These descriptions have been rewritten to in Line 240-242, and marked in red font.
Comment 4: “Figure 5 FXRD patterns of C-film, TA/C-film and ZMP/C-film” – please perform the designation of XRD patterns.
Response: Thanks for the reviewer’s suggestions. The XRD patterns has been modified to convey as complete information as possible. Figure 5 has been replaced with a new XRD patterns. FXRD of Line 399 corrected to XRD, and marked in red font.
have been marked in red font.
Comment 5: “Kinetics of polyphenol release” – what is the role of this kinetic study. The polyphenols are release into the fruits or what. What is the relevance?
Response: We sincerely appreciate the valuable feedback from the reviewers. This study has confirmed that the antioxidant activity of ZMP/C-film was related to ZMP release. To preliminarily explore the release mechanism of ZMP, the data has been fitted to different kinetic equations. In preservation experiment, ZMP/C-film was used to cover the polystyrene containers mouth to preserve strawberries. The release of ZMP due to their encapsulation with chitosan was related to the structural properties of ZMP/C-film. In the internal environmental system composed of containers, strawberries and ZMP/C-film, the release of ZMP may be accumulate more ZMP on the surface of the film, and play an antioxidant role, such as reducing the entry of external oxygen.
Comment 6: 2.2.2. Purification and analysis of ZMP” this paragraph must be rewritten due to poor English
Response: Thanks for the reviewer’s kind advice. The paragraph of “2.2.2. Purification and analysis of ZMP” has been rewritten, and marked in red font.
We tried our best to improve the manuscript and made some changes in the manuscript. Should you have any questions, please contact us without hesitate.
Once again, thank you very much for your comments and suggestions.
Best wishes!
Sincerely yours,
Dr. Bianfang Hu
Department of biological science and technology, Jinzhong University, Yuchi 030619, P.R.C
E-mail: [email protected]
Author Response File: Author Response.docx
Reviewer 2 Report
The author's made all the requested revisions suggested by me and other reviewers.
Accept in current form.
Best wishes!
Author Response
Dear Reviewer,
We sincerely appreciate your evaluation of our paper. The point to point responds the reviewer’s comments are listed as following:
Comment: The author's made all the requested revisions suggested by me and other reviewers.
Response: Thanks for the reviewer’s high evaluation for our manuscript. The encouragement is very important. it is not only a recognition of our science research, but also is the source of power that we continue to do the study of active packaging film.
Should you have any questions, please contact us without hesitate.
Once again, thank you very much for your comments and suggestions.
Best wishes!
Sincerely yours,
Dr. Bianfang Hu
Department of biological science and technology, Jinzhong University, Yuchi 030619, P.R.C
E-mail: [email protected]
Author Response File: Author Response.docx
Round 3
Reviewer 1 Report
The paper is improved therefore can be published in this journal.
The English language is satisfactory
