Valorization of Black Beans (Phaseolus vulgaris L.) for the Extraction of Bioactive Compounds Using Solid-State Fermentation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript detailed the optimal condition of solid state fermentation of black bean to get the highest polyphenol contents.

The manuscript could be minor revised following the suggestion before suitable for publication.

1. Introduction, please add more relevant previous studied if there are more.
2. The results and discussion: Line 148, please add more discussion with mechanism which may cause increasing of some minerals.
3. Line 160, The comparision with quantification could be help with more clear picture to readers.
4. Line 174, What is the reason that SSF with filamentous fungi improved level of bioactive compounds in black bean, may be possible mechanism.
5. Line 214, only factor humidity was not significant, more explaination could be added. 
6. Conclusion, the concern of application of fermented black bean before using in food, phramaceutical and cosmetics could be mentioned.

Author Response

Dear Reviewer

We greatly appreciate the time you took to review our manuscript. Your valuable comments will greatly enrich our document. Below is a response to each of your comments.

This manuscript detailed the optimal condition of solid-state fermentation of black bean to get the highest polyphenol contents. The manuscript could be minor revised following the suggestions before being suitable for publication.

Comments 1: [Introduction, please add more relevant previous studied if there are more.]

Response 1: There are very few works in the literature, we added another reference that is interesting for our introduction (lines 62-67).

 

Comments 2: [The results and discussion: Line 148, please add more discussion with mechanism which may cause increasing of some minerals.]

Response 2: The description of these mechanisms in the literature is very poorly studied. However, we add a reference that may explain this variability in mineral concentrations in beans (Lines 158-161).

 

Comments 3: [Line 160, The comparison with quantification could be help with clearer picture to readers.]

Response 3: In the work of Sepúlveda et al., condensed polyphenols are not quantified, which is why we only mention the ability of Aspergillus niger GH1 to degrade substrates rich in polyphenols.

 

Comments 4: [Line 174, What is the reason that SSF with filamentous fungi improved level of bioactive compounds in black bean, may be possible mechanism.]

Response 4: One of the possible mechanisms is the action of certain enzymes to release polyphenolic compounds. We've added a reference that helps support this theory. (Lines 188-192)

 

Comments 5: [Line 214, only factor humidity was not significant, more explanation could be added.]

Response 5: The new reference explains why humidity doesn't affect fermentation. (Lines 224-226)

 

Comments 6: [Conclusion, the concern of application of fermented black bean before using in food, phramaceutical and cosmetics could be mentioned.]

Response 6: The conclusion was improved.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript titled “Valorization of black beans (Phaseolus vulgaris L.) for the extraction of bioactive compounds using solid-state fermentation” presents an interesting research object and was good written. However, a crucial methodological problem was observed. The authors uses only a Placket-Burman experimental design, usually this approach is used for screening of variables, then after the indication of the variables that most influence the process, other experimental design with greater statistical robustness as full factorial design and Central Composite Rotational Design (CCRD) for the evaluation of the effects and interactions of variables and optimization, respectively, for a more complete understanding of the process. Then, the statistical approach choices by the authors is very limited and consequently the findings obtained and the discussion needs more statistical support. Therefore, I recommend that the preliminary results be taken as a basis for carrying out other experimental plans, which implies carrying out more experiments, before the manuscript is considered for publication. Moreover, minor improvementes are needed: (1) The Introduction needs improved, specially concerning to the advantages to use of the SSF as tool for improve the extraction of bioactive compounds; (2) The quality of Figures 1 and 2 needs to be improved and (2) The discussion can be improved, specially 

Author Response

Dear Reviewer

We greatly appreciate the time you took to review our manuscript. Your valuable comments will greatly enrich our document. Below is a response to each of your comments.

Comments 1: [The manuscript titled “Valorization of black beans (Phaseolus vulgaris L.) for the extraction of bioactive compounds using solid-state fermentation” presents an interesting research object and was good written. However, a crucial methodological problem was observed. The authors uses only a Placket-Burman experimental design, usually this approach is used for screening of variables, then after the indication of the variables that most influence the process, other experimental design with greater statistical robustness as full factorial design and Central Composite Rotational Design (CCRD) for the evaluation of the effects and interactions of variables and optimization, respectively, for a more complete understanding of the process. Then, the statistical approach choices by the authors is very limited and consequently the findings obtained and the discussion needs more statistical support. Therefore, I recommend that the preliminary results be taken as a basis for carrying out other experimental plans, which implies carrying out more experiments, before the manuscript is considered for publication]

Response 1: We respect and will take your comments into account for future publications; however, at this time, it is impossible to extend the experimental phase. I will list some reasons for this.

Objective of work. We believe that studying the conditions of the fermentation process is very important; however, the objective of this manuscript is not to optimize this process.

Time. Unfortunately, extending the experimental phase involves adding time that was not previously considered, and this will affect our work schedule. Optimizing the process could extend up to three more months of work.

Human resource development. This research is part of Dulce W. González-Martínez's doctoral thesis. Adding an experimental phase affects our student's degree process and has other negative consequences for her training.

We consider that the Pareto diagram and the analysis of variance statistically and adequately describe the exploratory evaluation of the solid-state fermentation process.

We apologize again for this inconvenience and hope for your understanding.

 

Comments 2: [Moreover, minor improvements are needed: (1) The Introduction needs improved, specially concerning to the advantages to use of the SSF as tool for improve the extraction of bioactive compounds].

Response 2: Reference seven was added to explain the effect of SSF on the production of bioactive compounds. (Lines 45-50).

 

Comments 3: [(2) The quality of Figures 1 and 2 needs to be improved]

Response 3: The quality of figures 1 and 2 has been improved.

Comments 4: [and (2) The discussion can be improved, specially.]

Response 3: Some references have been added to improve the quality of the discussion (References 25, 28, and 35). This comment appears to be cut off. We'll be happy to address any additional comments.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors answered some of the questions, resulting in improvements in the quality of the manuscript. However, it is necessary for the authors to mention the future perspectives of the work, especially related to the optimization of the fermentation process as a tool for the extraction of phenolic compounds from black beans.

Author Response

Dear Reviewer

We greatly appreciate your willingness and time to review our manuscript. All your comments will help improve our quality. Below, we respond to your comment:

Comments 1: [The authors answered some of the questions, resulting in improvements in the quality of the manuscript. However, it is necessary for the authors to mention the future perspectives of the work, especially related to the optimization of the fermentation process as a tool for the extraction of phenolic compounds from black beans.]

Response 1: Process optimization is essential for improving yields in extracting polyphenolic compounds. We've added a reference (lines 235-238).