Identification of Sensory and Voltammetric Markers of Regional Typicality: Tempranillo Rioja Wines as a Case Study

Round 1

Reviewer 1 Report

The manuscript entitled “Identification of sensory and voltammetric markers of regional typicality: Tempranillo Rioja wines as a case study” is focused on utilize sensorial trials and voltammetric analyses to discriminate different red wines according to its geographical origin. This work is well written and structured, but in my opinion there are important issues to response, particularly related with if the experimental design is appropriate to test the objectives.

1. Introduction section only discuss about the concept of typicality and how sensorial properties of the product can be used to identify regional differences for categorization and identification of origin. The use of voltammetric data apply to this end should be explained in detail, including the advantages and disadvantages compared with other chemical methods.
2. Complete information about geographical location, soil types, climatic characteristics, grape varieties, etc. of the studied sub-regions should be provided at Introduction section.
3. The experimental data set chosen could invalidate the results obtained because the choice of wine samples obtained from several grape varieties (coupage of red and white grape varieties) as well as produced in different years introduces variability factors that have not been taken into account. The total number of samples in the study is also insufficient to obtain reliable results, as the authors discussed at Conclusions section.
4. The particular winemaking processes of each producer introduce appreciable differentiation factors in the analytical parameters obtained and in the sensory characteristics of the final products (samples); therefore, in my opinion the use of a single red variety grown at the different subzones studied, as well as elaborated under the same experimental conditions would show the regional differences in a more accurate and reliable way.
5. Without evaluating whether the use of voltammetry analysis is appropriate for this purpose or not, the analysis of these wine samples is not sufficient to obtain consistent results for its use as a discrimination technique.
6. The limitations that I find in the design of the experiment mean that conventional, spectrophotometric, and voltammograms analyses do not have statistical validity for this purpose.

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Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The topic of the manuscript is interesting, as the results can contribute to better knowledge of typicality cues of wines from the Rioja sub-regions and help in the promotion of these wines. Overall, the manuscript is clearly written, but I have some suggestions for its improvement and there are few points that need clarification:

-overall in the manuscript: The use of terms needs to be harmonized: typicity/typicality. Also, please check keywords.

- L15: "al" - probably a typo. Please check.

- L36: correctly cite the ref. [1]

- L114-121: The rational for using this voltammetric method should by better explained and justified.

- L145-147: Please reformulate the sentence in order to fit into the sensory analysis part.

- L148: please provide standard deviation for the average age of assessors.

- L186 and elsewhere in the manuscript: I suggest to use abbreviations consistently after you've introduced them.

- L243: please check (only b*)

- L263: I suggest "wine sample"

- Results and discussion: I suggest that the order of presented results is the same as the order of methods in 2. M&M

- Table 2: Lactic acid - unit missing?

- L303: delete the second full stop at the end of the figure title.

- L326: On what basis did you define the 15% limit?

- L431: I suggest to reformulate from a question to a title

- L469: Delete the second full stop at the end.

- L477-488: Avoid repeating from the Results.

- L491-496: How was objectivity ensured in the categorization step performed by the experimenters? Could this step be a limitation of the method used and the results obtained?

Minor editing in English language is required. Please check for typos.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The Authors have chosen a topic, related to the discrimination of Tempranillo Rioja wines by the means of sensory analysis and voltammetric methods. The chosen scope of the paper are wines, which originate from a specific region. It is always a special concern how to identify and validate the origin of these food and beverage items. From that point of view the manuscript’s topic choice is valid and actual.

In lines 26-28 we read: “This is the first time scientific research establishes the typical regional character 26 of young Tempranillo Rioja wines, which includes a common and shared profile combined with the 27 specificities linked to each subregion”. This statement in its form is true, however there are available papers which deal with similar (but certainly not identical) topics. Here are two examples, just for the information of the Authors. Some references, similar to this might be included in the manuscript:

Etaio, I., Albisu, M., Ojeda, M., Gil, P. F., Salmerón, J., & Elortondo, F. P. (2010). Sensory quality control for food certification: A case study on wine. Method development. Food Control, 21(4), 533-541.

Garde-Cerdán, T., da Costa, N. L., Rubio-Bretón, P., Barbosa, R., Baroja, E., Martínez-Vidaurre, J. M., ... & Pérez-Álvarez, E. P. (2021). The most important parameters to differentiate Tempranillo and Tempranillo Blanco grapes and wines through machine learning. Food Analytical Methods, 14(11), 2221-2236.

In the Introduction section the reasoning of wine typicality is logical, mentioning a variety of applied methods and approaches of that field. The Free Sorting Task and the Free Description Task is clearly written in the Materials and methods section. The number of samples (30) is relatively high, however I understand that the Authors wanted to include the diversity of the categories in the study, and the applied task (sorting and description) are relatively easy to perform. It was an interesting technique that they applied a pectine solution for taste neutralizing.

Figure 2 is a very complex and demonstrative overview of the two sensory test outcomes.

Generally from the sensory point of view, it is a well-established research manuscript.

Author Response

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Reviewer 4 Report

Paper writing and conceptualization appear adequate for the purpose of the journal. Bibliographic sources appear adequate, and the topic is of interest for the scientific community and justifies the purpose of the research.

The methodology shows hypotheses consistent with the statistical methodology and processing used, and clearly identifies significant differences from results obtained.
The results obtained are consistent with the methods used and are represented in a clear and understandable form.

From the above indications, in the opinion of this reviewer the paper is suitable for publication in its present form, both for topic interest and for content and results obtained.

Q1.  What is the main question addressed by the research?
The identification of markers for wine typicality.

Q2.  Do you consider the topic original or relevant in the field?  Does it address a specific gap in the field?
The topic is of interest for the scientific community and justifies the purpose of the research.

Q3.  What does it add to the subject area compared with other published material?
The paper deals with new relationships in wine markers.

Q4.  What specific improvements should the authors consider regarding the methodology?  What further controls should be considered?
The methodology shows hypotheses consistent with the statistical methodology and processing used, and clearly identifies significant differences from results obtained.

Q5.  Are the conclusions consistent with the evidence and arguments presented and do they address the main question posed?
The results obtained are consistent with the methods used and are represented in a clear and understandable form.

Q6.  Are the references appropriate?
Bibliographic sources appear adequate.

7.  Please include any additional comments on the tables and figures.
None.

English form is fine.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

This manuscript has been noticeably improved. The authors have addressed all my objections. The limitations of the study have been showed in conclusions section. Therefore I recommend acceptance of this article for publication.