Development of a Semi-Industrial Kefalotyri-Type Cheese Using Thermized Milk from Native Epirus Sheep Breeds and Autochthonous Starter and Adjunct Cultures

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this study, autochthonous starter and adjunct cultures were used in the production of traditional Greek Kefalotyri cheese. While the topic may be of interest to Fermentation readers, the manuscript in its current form presents several substantial issues that need to be addressed before it can be considered for publication.

One of the major concerns relates to the experimental design. The authors evaluated the potential of an autochthonous mix of starter and adjunct cultures for producing traditional Greek Kefalotyri cheese. In this study, the “traditional” Kefalotyri control was manufactured using an autochthonous starter culture mix (ST1 + M78 + KE109), while the experimental Kefalotyri cheese was produced with the same starter culture plus an autochthonous adjunct culture (H25, KFM7, and KFM9). However, the current design does not allow a proper evaluation of whether the autochthonous starter mix can replace the commercial starter culture (traditionally used). To provide a valid benchmark, a cheese produced under traditional conditions using the commercial starter should have been included. Furthermore, the authors used mildly thermized milk (65 °C, 30 s) instead of the pasteurized milk traditionally used (72 °C, 15 s, or 68 °C, 10 min in an open-batch process). 

Another major concern is about the excessive and irrelevant citations. Throughout the manuscript, the number of references is excessive, with many appearing tangential or not directly relevant to the data presented. The current total of 89 references is well above the typical range and can hinder clarity. For instance, the introduction alone contains 34 citations—almost enough for the entire manuscript. I recommend a more focused and concise background, limiting the total number of references to no more than 40, and selecting only those that directly support the research rationale. The current manuscript is 30 pages long. It should be shortened to fewer than 20 pages to improve clarity and readability

The abstract should be shortened. The current abstract contains a total of about 441 words. Did the authors follow the journal instructions. https://www.mdpi.com/journal/fermentation/instructions: The abstract should be a total of about 200 words maximum.

The Materials and Methods section is currently very detailed. Consider shortening it by focusing on the essential information needed to reproduce the experiments.

Similarly, the Results section contains a lot of detail, which can make it difficult to follow. Streamlining this section to highlight the key findings would improve readability. While the results are clearly presented in tables with statistical significance, readers may find it challenging to extract overarching patterns. I suggest considering multivariate analyses, such as principal component analysis, to facilitate data visualization and interpretation, especially for tables of metabolites (e.g. volatiles, organic acids). Additionally, a heatmap with a dendrogram could be used to highlight differences among the cheeses.

The Discussion section could benefit from a slightly stronger focus on the study’s own data. Emphasizing the authors’ findings and using references mainly to support the interpretation may help make the section clearer and more concise.

The conclusion is currently quite long (about 22 lines). It might be clearer if it were condensed to around 5–6 lines, focusing on the main take-home messages.

Furthermore, several sections of the Materials and Methods appear similar to the authors’ previous publications. It would be helpful to rephrase these passages to enhance originality. For example:

Line 321-338: Fermentation 2023, 9(4), 345; https://doi.org/10.3390/fermentation9040345
Line 344-370: Fermentation 2023, 9(4), 345; https://doi.org/10.3390/fermentation9040345
Line 430-435: https://doi.org/10.1016/j.idairyj.2004.03.009
Line 437-443: https://doi.org/10.1016/j.idairyj.2004.03.009
Line 446-448: Fermentation 2023, 9(4), 345; https://doi.org/10.3390/fermentation9040345
Line 450-454: Fermentation 2023, 9(4), 345; https://doi.org/10.3390/fermentation9040345
Line 468-474: Fermentation 2023, 9(4), 345; https://doi.org/10.3390/fermentation9040345

Additionally, several lines in the Introduction appear to be identical to text from previous publications. For example
Line 111-115: https://doi.org/10.1016/j.idairyj.2022.105369
Line 115-123 https://doi.org/10.1016/j.idairyj.2022.105369

While the inclusion of references is appreciated, paragraphs should not be copied verbatim from previous sources. Rewriting them in the authors’ own words will improve clarity and originality."

 

Other comments

Line 2-4 "Exploring the semi-industrial production of traditional Greek Kefalotyri cheese using thermized milk from native Epirus sheep breeds and native starter and adjunct cultures"

Based on the points mentioned about “traditional Greek Kefalotyri”, I am not sure that this title accurately reflects what the authors actually addressed without proper controls.

Line 174 "2.1. Traditional Kefalotyri Cheese Manufacturing Protocol and Modifications Made"

The section 2.1. is unnecessarily long and should be shortened for clarity. Please move Figure 1 to supplementary material and it would be beneficial for readers if some photos illustrate the process.

Author Response

Dear Reviewer 1

Please refer to the attached PDF file with our responses to comments.

Thank you. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript represents investigation into the semi-industrial production of traditional Kefalotyri cheese using thermized milk and native lactic acid bacteria (LAB) starter and adjunct cultures. The authors have effectively demonstrated a comprehensive analysis encompassing microbiological, physicochemical, biochemical, and volatile profiles of the produced cheeses. The study is well-structured and provides valuable contributions to the field of cheese technology and microbiology, specifically for enhancing traditional dairy products through optimized native culture applications.

 

Comments:

• the abstract is slightly lengthy. It could benefit from a more concise presentation of critical findings, highlighting the most impactful differences between control (C-cheese) and novel cheese (N-cheese)
• in methods, add are recommended on the decision criteria for selecting specific strains of LAB and detailed descriptions of culture preparation and handling to ensure reproducibility
• tables (particularly Table 2 and Supplementary Table S1) appear complex. Consider breaking down or summarizing data visually (graphs or figures) to enhance readability
• the discussion is robust, linking results effectively with previous research. Nevertheless, further exploration of the implications of observed differences (e.g., reduced diversity of volatile compounds in N-cheese) on sensory perception and consumer acceptance would strengthen the manuscript
• the role of adjunct strains in cheese maturation and their potential impact on the sensory properties and acceptance by consumers could be discussed more comprehensively.

Author Response

Dear Reviewer 2 

Please refer to the attached PDF file with our responses to comments.

Thank you 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I sincerely appreciate the authors’ clarifications and the improvements made in response to my previous comments. However, I still consider that the current experimental design does not allow a proper evaluation of the potential for producing a “traditional” Kefalotyri cheese. Unless the title and objectives are rephrased to reflect a different scope (e.g., “Kefalotyri-type cheese”), this issue remains unresolved. A potential title could be: “Development of a semi-industrial Kefalotyri-type cheese using thermized milk from native Epirus sheep and autochthonous starter and adjunct cultures.” I believe this adjustment would help clarify the scope of the study and avoid potential misunderstandings.

Author Response

Dear Reviewer 1

Please refer to the attached Word file with our respones on your R1 report.

Author Response File: Author Response.docx