From Bakery Leftovers to Brewing Sustainability: Fermentation of Spent Grain with Yarrowia lipolytica and Lactobacillus acidophilus

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study explores using Yarrowia lipolytica and Lactobacillus acidophilus to ferment brewer's spent grain (BSG), transforming bakery and brewing waste into high-value products. The data were well analyzed, and the manuscript were organized in proper way. Here, there are recommendations for improvement.

1.      The introduction is overly wordy. It should be streamlined to more succinctly present the background and objectives of the study. Same to each part of the result session.

2.      Clearly explain why specific indicators—such as microbial cell counts, reducing sugar content, pH level, total titratable acidity (TTA), and fatty acid composition—were chosen. Provide context on how these indicators relate to fermentation performance and why they are important for evaluating the process.

3.      Table 1 is difficult to interpret. Specify which microorganism and substrate correspond to each set of values, and clearly state the units for each indicator to enhance readability.

4.      Ensure all tables include units for measured values. For example, Table 6, which shows TTA concentrations, lacks units. Adding units will improve clarity.

5.      Correct minor typographical errors, such as the misspelling of "e" in line 212.

6.      Where possible, convert tables into column graphs to better illustrate significant differences. Highlight significant results directly in the figures to make the data clearer and more accessible.

7.      Please pay attention to the format, especially references.

Comments on the Quality of English Language

Please keep the words as concise as possible.

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper entitled "From Bakery Leftovers to Brewing Sustainability: Fermentation of Spent Grain with Yarrowia lipolytica and Lactobacillus acidophilus" is devoted to an optimization of food leftovers, namely, bakery products. The problem of the expired products processing is a daunting challenge for the so-called developed countries, where culture of consumption demonstrates noticeable signs of degradation over the last few decades. Of course, the most optimal way to address this challenge should include the development, understanding and practical implementation of ideas about rational consumption per person, depending on his age, biological needs, place of living, etc. But since this is as an unattainable goal (like the solution of world hunger problem), this challenge can be addressed by the development of methods for at least partial processing of food leftovers.

The authors performed fairly competent preliminary research using a set of modern physical and chemical methods. They outlined a plan for further work. However, the following issues should be addressed and clarified before publication. First, all the figures are very fuzzy. The figures should be improved or redrawn. Second, in fact, the conclusions are absent in the paper. Instead, the authors presented plans for future. Despites the importance of such plans, the conclusions should be more specified. Third, the number of references (36), in my opinion, is rather insufficient for such an important topic. Fourth, statistical data, which will further highlight the importance of the research, should be added to the introduction.

Overall, the paper could be published in Sustainability after addressing of the above minor comments.

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Papey by Lalić et al: From Bakery Leftovers to Brewing Sustainability: Fermentation of Spent Grain with Yarrowia lipolytica and Lactobacillus acidophilus regarding bakery leftovers as a substitute for malt in brewing and fermentation of BSG by mentioned microorganisms is very interessting in utilization of byproducts, improving sustainability and inovating food products. Besided good experimental plan and clear and understandable scientific writting valorizes BSG, reduces waste and promotes circular economy. The results section with statistical data are easy to understand and follow. The quality of Figures 2 and 3 must be improved. The references must be rechecked since several errors occured. 

Comments for author File: Comments.pdf

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf