Preparation and Characterization of Microcrystalline Cellulose/Polylactic Acid Biocomposite Films and Its Application in Lanzhou Lily (Lilium davidii var. unicolor) Bulbs Preservation

Round 1

Reviewer 1 Report

The paper has a logical structure and rich content. It systematically presented the preparation, characterization of MCC/PLA composite films from different MCC sources, and their application in preserving Lanzhou lily bulbs. Multiple characterization techniques were used to comprehensively analyze the effects of different MCC sources and addition amounts on the properties of MCC/PLA composite films. Simulation storage experiments were carried out to compare the preservation effects of different composite films. Overall, this is a well-written paper with solid data, reasonable innovations, and good applied value. My major comments are:

1. Antibacterial properties of the composite films could be characterized.

2. Long-term preservation effects of the composite films under different conditions could be investigated.

3. Abstract:

Line 15 - Change "Sustainability 2023" to "Title of Journal, Year" to match journal requirements

4. Introduction:

Expand on importance of PLA and its limitations in paragraph 2

Provide more background on use of natural fibers as reinforcement in paragraph 3

5. Materials and Methods:

Line 105 - Change "PLS pellets" to "PLA pellets"

Add details on specific models and manufacturers for equipment used

Provide more details on statistical analysis methods

6. Results and Discussion:

Line 270 - Define acronyms (SEM, MCC) at first use

Line 290 - Explain why lower tensile strength observed for SSS MCC/PLA

Line 300-301 - Clarify mechanisms causing reduced strength at higher MCC

Line 340-345 - Discuss why different MCCs vary in thermal stability impacts

7. Conclusions:

Summarize the key novel findings and contributions of this work

Provide recommendations for future research based on limitations

8. Figures and Tables:

Increase font size and clarify labels for readability.

Add more informative captions to help reader interpret results.

Overall, the language quality is good but there are some areas that could be improved:

1. There are occasional grammar mistakes and awkward phrasing throughout the paper. Carefully proofread to correct these issues. For example:  "the biocomposite films became slight rougher with sparse spots which became denser as the content of MCC increased" could be revised to "the biocomposite films became slightly rougher, with sparse spots that increased in density as the MCC content increased"

2.  Some sentences are overly long and complex. Break these up into shorter, clearer sentences when possible. For example break up the sentence on lines 291-294.

3. The tone is appropriate for a scientific paper but can be a bit wordy in places. Simplify language where possible. For example, "As illustrated in Fig. 2" can just be "Fig. 2 shows".

4. Be consistent with verb tenses within paragraphs. Some shift between past and present tense.

5.  There is occasional awkward phrasing or word choice issues. For example: "SSS MCC/PLA-3 had favorable preservation effectness of lily bulbs" sounds unnatural. Consider rephrasing to "SSS MCC/PLA-3 showed a favorable preservation effect on lily bulbs."

6. Some terms could be explained more clearly for audiences outside the field, like "hunter color values"

7. Abbreviations should be defined at first use, like PAL

8. Be consistent with British or American spelling (favourite vs favorite)

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Haiwi Ren et al. conducted a study on the preparation and characterization of biocomposite films comprising microcrystalline cellulose (MCC) and polyactic acid (PLA). They enhanced the tensile strength and water insolubility of the PLA film by incorporating 3% MCC. 

This manuscript presents comprehensive data on films composed of various MCC types derived from JAS, SSS, CHR, and DG, interwoven with PLA, showcasing the remarkable versatility of the MCC/PLA composite. Additionally, the study demonstrates the film's efficacy in preserving a delicate material, specifically the Lanzhou lily (bulb). This demonstration is quite impressive. Although this study has the potential for publication in "Sustainability," certain corrections need to be addressed before it can be published.

 

1. SEM data reveals that a high concentration of MCC leads to agglomeration of fine crystals. To avoid this, I propose sonicating the MCC/PLA blend followed by rapid drying. Is this feasible?
2. Regarding film water solubility, the authors discuss the role of hydrogen bonding between the polymer matrix and MCC, attributing it to reduced water solubility. If this holds true, I speculate that increasing the MCC content in the film would further decrease its water solubility due to stronger hydrogen bonding, despite particle agglomeration and coarsening. However, the film containing over 6% MCC unexpectedly exhibits an increase in water solubility. Why? Furthermore, can the strength of hydrogen bonding be determined using an IR spectrometer?
3. For light transmittance, the authors assert the enhancement of the UV-blocking rate in the composite membrane; however, in actuality, it has only improved by a few percentage points compared to the reference film, and it cannot be stated that it effectively shields UV rays  (Fig. 6). 
4. The authors measure the color change of lily bulbs using a colorimeter. Since lily bulbs are not commonly found worldwide and are emphasized as the subject, I recommend including a photograph depicting the lily bulbs and their color changes.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf