Impact of High-Power Ultrasound for Barrel Regeneration on the Extraction of Wood Volatile and Non-Volatile Compounds

Round 1

Reviewer 1 Report

The authors aim to evaluate the impact of HPU on the extraction of wood volatile and non-volatile compounds. The topic is very interesting, as well as the comparison of HPU with steam treatment. An extensive number of sophisticated analyses are employed for this reason, which would help reveal qualitative but also quantitative differences.

However, and regardless of the problems in understanding due to the poor use of English, the experiment setup is not efficient, and cannot be used to provide solid answers as the authors have used only one barrel per modality. Barrels are characterized by high levels of variability regarding their chemical composition, so comparing only two different barrels is not enough to draw safe conclusions. The authors could have used all three barrels to create an average but neither this is possible, as the wine in the 2-year aged barrel is from a different estate. Finally, in this experiment, it cannot be proven that the procedure is microbiologically stable, as there has been no Bret infection in control wines to examine the effect of HPU on it.

For these reasons my recommendation is to reject this article in its present form.

Author Response

I understand your concern regarding the set-up experiment. We used two barrels for HPU and two barrels for steam for each year. The comparison was between HPU and steam. It was our first concern. There is always a possibility to improve a research project. At the time, some choices have been made according to our time and the cost of the experiment (barrels, wine, analyses). It was the scale up of the HPU research initiate at our lab and we try to manage it according to our requirements.

For the microbial point of view, you’re right we cannot say that. So, we change in the manuscript that we didn’t notice any Brettanomyces contamination.

Finally, we did a global English correction.

 

Reviewer 2 Report

This paper deals with an interesting application of high power ultrasound for sanitation of wine barrels. The manuscript is technically good, however some minor corrections are needed. Also the English needs a robust revision.

The authors have applied a thermal treatment of 60 °C combined to High Power Ultrasound, not simply High Power Ultrasound. This should be clearly reported in Figure 1 and in the discussion of the results. So, please use an abbreviation which clearly states that HPU were combined with a heat treatment at 60 °C for 6 min.

Line 16. We observe that Only small significative increase…

Line 29. …a frequent problem occurring in wines…

Line 116. ..to compare results with HPU treatment combined to heating at 60 °C…

Line 117-118. ‘The total energy consumption….’ The authors forgot to report the energy needed to heat up the water in the barrel to 60 °C.

Line 131-132. Please specify the analytical method, not only the commercial website. It is probably a multiparametric wine analyser.

Line 134. Research of Brettanomyces in Wine

Line 152; line 272 and all through the text. Guaiacol (check the spelling)

Line 172-173. …were evaluated by sensory analysis

Section 3.1 Oenological Parameters, please keep using the past tense

Line 335. …could be explained…please check the spelling

Reference 27. Slaghenaufi et al. What type of contribution is it? Is it a thesis? An article? It is not clear.

Reference 29. Chatonnet et al., same as above.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

The publication is of great interest to the wine industry, especially in terms of barrel cleaning methods. The methodological scope presented in the works does not raise any objections. The presented research methods allow to draw correct conclusions. The results are clearly presented. Only the cited literature can be more up-to-date.

Author Response

Thank you for the positive review

Round 2

Reviewer 1 Report

The text has been significantly improved due to the correction in English. Moreover, the authors clarified that two barrels per treatment were used (the first version of the text gave the impression that one barrel per treatment was used which would be unacceptable), and corrected the conclusion regarding Brettanomyces. I find these changes satisfactory and I recommend Accept in present form.