Cellulose-Based Biopolymers from Banana Pseudostem Waste: Innovations for Sustainable Bioplastics

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Overall, the article describes the cellulose extraction method and introduces cellulose and its raw materials. However, it fails to provide a quantitative analysis of its potential as a bioplastic, such as its physical properties. The authors need to systematically present its potential, for example, by comparing it to current bioplastics or traditional plastics in various aspects. Detailed comments are as follows:

1. In the abstract, the authors mentioned about the characterisation of cellulose, but they only listed those testing methods in section 7 like the research paper, without further discussion.
2. The author's title highlights banana pseudostem as a cellulose raw material, suggesting it's a key element of their manuscript. However, they completely omit this mention throughout the introduction. Furthermore, they only mention banana pseudostem very late in the article, while the first half of the article is like comparing bioplastics to typical plastics.
3. Suggest to remove section 1.2.
4. Section 2 mentions four summaries, but the above part fails to effectively summarize these conclusions, especially the first one.
5. Like the second suggestion, the author spent a large part of the article introducing bioplastics instead of focusing on cellulose, which made the article lose focus.
6. Similar, section 3.1 is too board, better to be more focusing on cellulose-based.
7. The manuscript contains several instances of redundancy. For example, the chemical composition of lignocellulosic acid is listed in the introduction, yet the authors describe these figures again in section 4.1. This is just one example, and recommend to reorganise the information to reduce redundancy.
8. The authors mentioned “Waste Material” in Figure 6, what are they, please also mention them in word.
9. Section 5 should serve as an introduction to sub-titles such as Section 5.1, 5.2, etc. Don't need to write out most of the content that will be introduced later.
10. In table 6, the authors list sample numbers 1-5 but not describe what are they. The authors should integrate the content of the paper and create a new table, rather than simply listing the experimental results from other papers.
11. In section 5.2, the authors mention various cellulose extraction methods. Similarly, they already introduced organosolv pretreatment in this section, but later added a section 5.2.2 discussing pretreatment, which creates redundancy. Again, suggest the authors to reorganize the article to reduce redundancy and improve flow.
12. In Table 8, the results should be compared systematically, for example by breaking down the cellulose extraction, crystallinity, etc., and removing unnecessary data.
13. In section 6.1, the title is cellulose acetylation, but the following content discusses esterification. Acetylation can be esterification, but esterification is not necessarily acetylation.
14. Some sentences are incoherent, for example in line 599 “Cellulose acetate is insoluble in water depending on the degree of substitution...”, it is better to rewrite it into “The solubility of cellulose acetate in water is depending on the degree of substitution…”. Another example is line 436 “Cellulose isolation and purification process and methods/techniques”, rephase it into “Methods of cellulose isolation and purification”.
15. In the discussion of section 8, the author did not mention banana pseudostem, making banana pseudostem unimportant in the article.
16. The resolution of all figures is very low, please use a higher resolution image.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

REVIEWER REPORT

 

Title of the MS: Cellulose-based biopolymers from banana pseudostem waste: Innovations for sustainable bioplastics

MS Number:                Waste-3916692          

Name of the Journal:   Waste, MDPI Publishers  

Article Type:                 Review Article                       

 

Reviewer Comments:

The title of the review article is found to be relevant for publication in the journal Waste. The abstract has been written well and explained the objectives and aim of the review article clearly. The introduction part has been written very informatively, particularly the importance of biopolymers (bioplastics) from the waste crop plant residues. The objectives and methodology sections have been written properly and explained clearly.

Further, the various components of the review article, such as Synthesis of key literature on bioplastics and identified gaps, types and classification of bioplastics-properties and application of bioplastics, advantages and disadvantages of bioplastics from natural sources, Properties of cellulose and cellulose derivatives for packing - Figure 3. Lignocellulosic material complexes, Table 5. Strengths and limitations of cellulose in packaging, sources of cellulose, Figure 5. Stepwise process for cellulose extraction from banana pseudostem, Figure 6. Application pathways of the various components of the banana pseudostem, viability of banana pseudostem waste for cellulose extraction, isolation and purification of cellulose from banana pseudostem waste, chemical composition of banana pseudostem, cellulose isolation and purification process and methods/ techniques-degumming/conditioning, pretreatment, hydrolysis/pulping, bleaching/ purification, cellulose modification for bioplastic films-cellulose acetylation, cellulose acetate film formation, cellulose characterisation such as kappa number, degree of polymerisation, colour measurement, mechanical properties, X-ray diffraction (XRD), thermal stability analysis, FTIR analysis, SEM analysis have been explained in good manner. The discussion and conclusion parts have been relevantly written and explained very well. References are found to be pertinent to the review article and also updated.

Specific comments:    

1. In line number 22: Please check the size of the microplastics ranges and provide correct data.
2. Please check the chemical formula of biomolecules provided in the text and presented in the standard format.
3. In Discussion and Conclusion: Post utilisation perspectives of the cellulosic biopolymers/bioplastics and packaging materials derived from waste banana pseudostem and other crop residues, such as bio compost preparations, energy generation in terms of biogas through anaerobic digestion and biofuel through solid energy pellet formation should be explained with the latest available literature. Then only the review article objectives, such as waste valorisation, industrial circular economy, nature-based solution and SDGs goals will be fulfilled.      

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

REVIEWER REPORT

 

Title of the MS:          Cellulose-based biopolymers from banana pseudostem waste:                                                      Innovations for sustainable bioplastics

MS Number:               Waste-3196692          

Name of the Journal:  Waste, MDPI

Article Type:               Review Article                       

 

Reviewer Comments:

The manuscript entitled “Cellulose-based biopolymers from banana pseudostem waste:  Innovations for sustainable bioplastics” is more suitable to be considered for publication in the journal Waste. As has been suggested by the reviewers, the manuscript has been thoroughly revised and rewritten. Moreover, the latest and relevant information has also been incorporated and discussed properly in the text. Particularly, the sentences have been reconstructed in a pertinent manner, and readability is found to be quite improved in an excellent way for attracting the audience of the scientific community. Nonetheless, the authors responded to the reviewers’ comments in properly and sequentially.