Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript proposes a two-stage RSM optimization strategy for seed melon compound fermented feed production using S. cerevisiae L23. The experiments were well conducted, and the work is interesting.  However, some issues should be addressed before being considered for publication.

1. It is recommended that the authors place greater emphasis on the novelty of the study, highlighting what is already established in the literature and the original contributions of their research.
2. The review presented in the introduction was superficial. It would be beneficial to provide a more in-depth explanation of the use of agricultural by-products in feed production and to cite previous studies in order to highlight how the processes already described in the literature differ from those investigated in the present study.
3. The introduction does not define Response Surface Methodology (RSM), which would be valuable even though it is a known approach. Including a brief definition would help to better contextualize the reader.
4. Section 2.5 presents the parameters used for the optimization of SMCM; however, it is not indicated whether these parameters were based on previous studies or defined according to some other criteria.
5. Section 2.5 should precede Section 2.3, since it presents the parameters that were tested, while Section 2.3 deals with the preparation of SMCM. The current order compromises the logical flow of the text, as it would be more logical to first understand which parameters are being considered before describing how was prepared.
6. It was observed that in the determination of the SMCM optimization parameters, most variables reach an optimal peak and then decline. It would be useful to include an explanation for this behavior. For example, the optimal temperature found was 30 °C, and increasing it led to a reduction in the activity of S. cerevisiae L23.
7. Including a comparison of the obtained results with those from other studies, especially in the Results and Discussion sections, would be important to contextualize the efficiency of the proposed experiments and to reinforce the relevance of the findings.
8. Why is section 3 titled "Results and Discussion" while there is another separate "Discussion" section, see line 390? Please reorganize accordingly.
9. Correct line 40 "...in seed melo juice" for "...in seed melon juice".
10. Correct line 67 "...a two-stage RSM..." for "a two-stage Response Surface Methodology RSM".

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In general, the document presents important information about fermentation processes. Optimization methods should be indicated, as in the initial stage, this appears to be a method of selecting the best conditions. The wording of the document should be carefully reviewed and corrected, including spacing between references.

Abstract
All abbreviations must be defined, even if they are only used in the abstract. Therefore, authors should define what NDF, ADF, or VC are and write the full name of Z. bungeanum.

Line 101. Correct 2.00 x 10⁸ CFU/mL

Lines 102, 104, 107, 113, 124, 125, 132, 233, 235, 237, 238, 240, 243, 248, 252, 253, 257, 258, 265, 269, 270, 272, 274, and 422. S. cerevisiae in italics.

Lines 114-116. Write the chemical formulas correctly.

Line 166. Isn't it written "proposed by ref. [17]?" It's enough to write "proposed by [17]" and correct it. The same thing happens on lines 179, 186, 195, 204, and 214.

Lines 233-244. The authors mention an optimization process, but it's not clear which method they used; furthermore, it seems more like a best-case method. Please clarify this situation.

Line 251. Adjust the section title since an optimization process isn't observed.

In Figure 3, what does CJSM mean?

The document needs a style correction. Many sentences are not clear. For example, on line 403, the optimization of S. cerevisiae is mentioned. Wasn't the fermentation process optimized?

Line 407. What amount of carbon can be considered excess?

Line 410. The authors indicate that The presence of butyric acid is an indicator of food spoilage. Is its concentration related to the amount of biomass? If so, how is it possible that they detected low concentrations of this acid when they were looking for a larger amount of S. cerevisiae biomass?

Line 427. Does the detected protein include biomass or is it just extracellular protein?

Comments on the Quality of English Language

The document must be proofread. The writing is very sloppy, so the authors must correct all typos in the document.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you for the opportunity to read the manuscript entitled:
“Optimised Co-Fermentation of Seed Melon and Z. bungeanum Seed Meal with Saccharomyces cerevisiae L23: Valorisation into Functional Feed with Enhanced Antioxidant Activity”
The manuscript concerns the interesting and economically relevant topic of biovalorisation of plant processing waste. The authors have chosen an interesting biological materials and set themselves the goal of optimising yeast biomass cultivation using the RSM method.
The manuscript is clearly divided into sections typical for research articles.
 
In my opinion, it is worth publishing, but the authors should first improve a few elements listed below:
1.      The introduction lacks information on the annual quantities of seed melon juice and Z. bungeanum pomace available in China, which would allow for a rough estimate of the economic potential of the research results. There is also no explanation as to why S. cerevisiae and specifically the L23 strain was used (or its characteristics) in the methodology.
2. Throughout the article, and particularly in the Introduction and Methodology section, the descriptions are unclear, which in my opinion is mainly due to linguistic imperfections in the manuscript. For example, the sentences in lines (numbering according to the PDF file): 85-87; 95-96; 98-99; 102
3. In the description of the Methodology, numerous elements require improvement, in my opinion.
- In line 89, it is stated that ‘Pectinase was purchased...’ without any details regarding the form of the product, catalogue number or pectinolytic activity. If possible, please provide these additional informations.
- The first sentence in the description of ‘Preparation of SMCM’ is unclear (ring?, inclined plane? )
 
- ‘melon juice as a carbon source’ I agree with the Authors, although this is based more on our assumptions :)  than on the results of the analysis (the authors did not specify in the text how much sugar the melon juice contained before fermentation, which is a pity as this would have allowed us to assess the efficiency of the conversion to biomass
- line 116 – what do the percentages of added pectinase mean? v/v? It is necessary to at least specify the form of the product and the batch number/production date or the specified pectinolytic activity/1ml, otherwise it is difficult to relate these results to the literature data.
- line 125 (optimal conditions) – did the authors determine these values earlier or did they know them from the literature? Perhaps it would be sufficient to describe these conditions and explain why they were used?
- The entire description of ‘Sensory Evaluation’ – after reading the manuscript, I find it difficult to understand why a sensory evaluation was carried out, where the parameter ranges and scores given in the table were taken from, and whether the testers were really experienced in testing fermented mixtures of melon juice with the addition of Z. bungeanum seed biomass. Is this product intended for human consumption?
- In point 2.11, please provide a reference to the literature or describe the method in more detail if it is the authors' idea.
- In line 182, the quantity is given as ‘fifty’ – I think that for consistency, this should be written as 50?

4. I have no major comments on the presentation of the Results and their description, but I believe that the chapter ‘Discussion of results’ could be expanded by at least 20% based on the available literature.
5. I think that after these minor corrections, the manuscript is worthy of publication.

Comments on the Quality of English Language

as I wrote in general comments:

Throughout the article, and particularly in the Introduction and Methodology section, the descriptions are unclear, which in my opinion is mainly due to linguistic imperfections in the manuscript. For example, the sentences in lines (numbering according to the PDF file): 85-87; 95-96; 98-99; 102

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I am overall satisfied with the author’s responses and changes to the manuscript. They have satisfactorily addressed my comments with new essential discussions, and the revisions made have significantly improved the manuscript. Therefore, I recommend that the revised paper be accepted.

Reviewer 2 Report

Comments and Suggestions for Authors

I appreciate the responses to the comments made on your article. No comments.