Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

There are no details regarding the parameters of chromatographic separations, both GC and HPLC.

How were the concentrations in g/L determined (Figure 2) if the surface area of the analytes was determined and no standards were used?

In what units is the time given in Figure 1?

Which axis relates to glycerol (Figure 5)? This compound is neither a sugar nor a volatile ingredient.

The lack of statistical methods makes it impossible to analyze the obtained data and draw conclusions.

Author Response

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Your attention is deeply appreciated.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

I attache my comments in a separate file.

Comments for author File: Comments.pdf

Author Response

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Your attention is deeply appreciated.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The study investigates the feasibility of brewing beer predominantly from stale bread to enhance sustainability in the food industry. Through adjustments in mashing parameters, optimal enzymatic activity for starch hydrolysis was achieved, enabling successful Pale Ale production with 50% bread substitution. Despite yielding slightly lower alcohol content, this method resonates with consumer preferences for sustainable and lighter beverages.

1.      However, the paper lacks clarity in articulating its unique contribution and originality within the broader field. It could benefit from discussing the current state of the food sector and incorporating insights from recent research, such as the valorization of cereal processing by-products (e.g., Foods 2024, 13, 506; 2023 Foods, 12, 721).

2.      Additionally, the introduction should delve deeper into bread waste utilization in beer production.

3.      The study fails to explore the role of functional food ingredients and agri-food innovations in the post-pandemic food sector.

4.      A notable drawback is the absence of comparison with existing literature on mashing parameter optimization for starch hydrolysis, mainly in beer production using alternative raw materials like stale bread.

5.      Moreover, the paper overlooks potential limitations encountered during the mashing process and lacks discussion on broader implications such as scalability and commercial viability.

6.      Alternative approaches for optimizing starch hydrolysis and maximizing sugar yield in beer production from bread waste remain unexplored.

 

7.      Furthermore, there is a missed opportunity to discuss the sensory attributes and consumer acceptance of beer brewed from stale bread compared to traditional varieties. 

Author Response

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Your attention is deeply appreciated.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The work has been revised in accordance with the suggestions included in the first review. I still have comments about the quantitative analysis of volatile compounds.

 

Page 7, Table 1.

Were the concentrations in the Table 1 correct? The concentration of acetaldehyde after fermentation (63.63 g/L) is higher than the concentration of ethanol (Figure 4). Other concentrations of volatile compounds also appear to be unusually high.

There are no statistics in this part of the work.

Compound names in the first column should begin with a capital letter.

I think that the results of quantitative analysis using GC are unreliable and should be removed from the paper.

Author Response

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Author Response File: Author Response.docx