Synthesis and Characterization of Chanar Gum Films

Round 1

Reviewer 1 Report

The paper entitled “Synthesis and Characterization of Chañar Gum Films” presents the formation and investigation of biopolymer films based on the polysaccharides obtained from chañar fruit (Geoffrea decorticans). The article is interesting and the authors performed a detailed analysis of the obtained material. The results are clearly presented, following proper methodology. The conclusions logical are based on the results. In my opinion the paper can be accepted for publication after some minor changes.

• In my opinion, the introduction is too long, authors should choose the most important information to be presented
• Lines 168-171 – the information about the HCl-Ascorbic Acid ratio should be given
• Also, the paragraph 2.2.1.1 should be rewritten – there is no need to describe the importance of viscosity in ‘materials and methods’ section
• In materials and methods section (line 276) – the operational range of the FTIR was 400-4000cm^-1, while in the results section (line 469) it appears as 4000-450 cm^-1 and in figures it is about 4000-700 cm^-1
• Line 306 – the type and model of used micrometer should be included
• Line 397 it should be Na₂CO₃ instead of NaCO₃
• Have the authors analyzed the polysaccharide composition of the obtained extracts?

Author Response

Reply

Reviewer 1: The paper entitled “Synthesis and Characterization of Chañar Gum Films” presents the formation and investigation of biopolymer films based on the polysaccharides obtained from chañar fruit (Geoffrea decorticans). The article is interesting and the authors performed a detailed analysis of the obtained material. The results are clearly presented, following proper methodology. The conclusions logical are based on the results. In my opinion the paper can be accepted for publication after some minor changes.

Dear Reviewer, thank you very much for your comments and positive response.

• In my opinion, the introduction is too long, authors should choose the most important information to be presented.

We appreciate the comments of the reviewer, the extension of the introduction is only a state-of-the-art approach on new polysaccharides.

• Lines 168-171 – the information about the HCl-Ascorbic Acid ratio should be given.

Data were added as requested by the reviewer.

• Also, the paragraph 2.2.1.1 should be rewritten – there is no need to describe the importance of viscosity in ‘materials and methods’ section

The phrase was removed as suggested by the reviewer.

• In materials and methods section (line 276) – the operational range of the FTIR was 400-4000cm^-1, while in the results section (line 469) it appears as 4000-450 cm^-1 and in figures it is about 4000-700 cm^-1

Data were corrected as suggested by the reviewer, 4000-700 cm^-1

• Line 306 – the type and model of used micrometer should be included

The data was corrected as requested by the reviewer, (line 271).

• Line 397 it should be Na₂CO₃ instead of NaCO₃

The data was corrected as requested by the reviewer.

• Have the authors analyzed the polysaccharide composition of the obtained extracts?

We have preliminary data, but they will be the subject of further studies for a future publication.

Reviewer 2 Report

The article has reported the synthesis and characterization of Chanar Gum and films. The authors are requested to answer the following doubts before the paper is considered for publication:

A thorough language and grammatical correction are required.

Abstract:

1. Please clarify the abbreviations in the first appearance.
2. What is meant by ‘favourable results’? Please use quantitative or relative parameters.
3. Restructure the last part with a clearer conclusion.

Introduction:

Unnecessary elaboration of the Introduction part is done. Please try to focus on the different utilities from Geoffroea decorticans and the untapped potentials. Then mention clearly the gap in research that this article wants to fill in. The novelty of work should be clearly mentioned.

Materials & Methods:

1. Please mention the source of all the raw materials.
2. How much solution is poured into each plate for film preparation?
3. Use either DRX or XRD.
4. Please report biodegradation as per ASTM.

Results & discussion

1. Line 455-456: Is it only the discontinuities that cause vapour permeation? Are the discontinuities a result of casting failure, if yes how can they be addressed?
2. What is the reason for the difference in film surface morphology between CHA and CHT?
3. What is meant by Frequency in Fig 3?
4. Why there is a difference in thermal properties, polysaccharides' molecular weight distribution can't be proved with the present experimental setup. Thus it is advised to support the idea with HPLC data.  How many replications were done for each graph?
5. Line 529-530: Please check the XRD peaks are for the crystalline regions.
6. If the XRD scanning was done between 3 and 30° then how is the graph reported from 5 to 60°?
7. Line 545-548: There is an ambiguity in the explanation that may be due to experimental failure. Please give substantial reasons behind the difference, when CHA and CHT showed similar 'characteristics as film-forming material' and 'the cohesion of the polymeric matrix structure' was not observed.
8. Please include statistical validation for the results esp Fig 8 and Table 6.
9. If weight cannot be reported for biodegradation, then correct the same in the methods. Please try to support the idea with chromatographic or FTIR analysis of the degraded fragments. Also, please correct Fig 11b, day 1 is missing.

Author Response

Reply

Reviewer 2. The article has reported the synthesis and characterization of Chanar Gum and films. The authors are requested to answer the following doubts before the paper is considered for publication:

A thorough language and grammatical correction are required.

Corrections were made as requested.

Abstract:

1. Please clarify the abbreviations in the first appearance.
2. What is meant by ‘favourable results’? Please use quantitative or relative parameters.
3. Restructure the last part with a clearer conclusion.

Corrections were made as requested.

Introduction:

Unnecessary elaboration of the Introduction part is done. Please try to focus on the different utilities from Geoffroea decorticans and the untapped potentials. Then mention clearly the gap in research that this article wants to fill in. The novelty of work should be clearly mentioned.

The central idea is to present the actuality of different polysaccharides, as state the art. As for chañar gum, there is no published scientific material, hence its novelty.

Materials & Methods:

1. Please mention the source of all the raw materials.

The raw material is put into the paper as requested by the reviewer.

2. How much solution is poured into each plate for film preparation?

50 mL.

3. Use either DRX or XRD.

As requested by the reviewer we use XRD.

4. Please report biodegradation as per ASTM.

The biodegradability method was developed in our laboratory and is similar to reference 33 and also to ASTM.

Results & discussion

1. Line 455-456: Is it only the discontinuities that cause vapour permeation?

Are the discontinuities a result of casting failure, if yes how can they be addressed?

These discontinuities do not affect the WVP.

2. What is the reason for the difference in film surface morphology between CHA and CHT?

Based on the intrinsic viscosity data and SEM images we assume that CHT is a dimer of CHA, but this information is not conclusive and more determinations are needed to confirm this.

3. What is meant by Frequency in Fig 3?

Frecuency: Number of particles of the same size that are repeated.

4. Why there is a difference in thermal properties, polysaccharides' molecular weight distribution can't be proved with the present experimental setup.

Although what the reviewer writes is true, but even so our data is useful even if it is approximate.

Thus it is advised to support the idea with HPLC data. 

We do not have HPLC in our laboratory, ours is broken.

How many replications were done for each graph?

The experiments were made in duplicate or triplicate specified in the experimental section

5. Line 529-530: Please check the XRD peaks are for the crystalline regions.

They can be traces of crystals typical of the biopolymer synthesis that do not represent a great contribution to the final material.

6. If the XRD scanning was done between 3 and 30° then how is the graph reported from 5 to 60°?

The data was corrected up to 60°.

7. Line 545-548: There is an ambiguity in the explanation that may be due to experimental failure. Please give substantial reasons behind the difference, when CHA and CHT showed similar 'characteristics as film-forming material' and 'the cohesion of the polymeric matrix structure' was not observed.

The data presented in the indicated lines (Now line 484-486) do not represent an ambiguity, they are data obtained from other novel biopolymers, and they are presented to show that the values obtained are in an acceptable range, since there are no values reported for CH.

8. Please include statistical validation for the results esp Fig 8 and Table 6.

Table 6 was corrected. But there are reference data that we cannot correct.

Figure 8, the error bars were included in the graph, but since they are such small values, they overlap the points of the curve and it is not possible to observe them.

 9. If weight cannot be reported for biodegradation, then correct the same in the methods. Please try to support the idea with chromatographic or FTIR analysis of the degraded fragments.

The degraded fractions are very difficult to quantify due to the adhesion of soil and microorganisms, so we opted for a qualitative-visual approach.

Also, please correct Fig 11b, day 1 is missing.

The day 1 is presented in fig 11B, please check. Day 35 is not observed because this film degraded much earlier, on day 25 as evidenced