Influence of Bunch Compactness and Berry Thinning Methods on Wine Grape Quality and Sensory Attributes of Wine in Vitis vinifera L. cv. ‘Monastrell’

Round 1

Reviewer 1 Report

The manuscript contains very interesting and useful data that can be of great practical importance.

The Introduction provides sufficient background and includes the relevant references.

lines 82, 83: The abbreviations 'CWI' and 'SAI' should be explained. 

lines 84-89: What is the novelty of the present research compared to previous literature data with regard to the influence of bunch compactness and berry thinning on grape quality? Was only the cultivar different or were the methods of bunch compactness and berry thinning different?

The methods are adequately described.line 114: Is there other way than manual? 

lines 271-272: Why did the authors not show the data?  

line 293: It has been written '(data not shown)'. What data has not been shown?

Table 2: What did 'control' mean? Was it 'compact bunch' like in Table 1?

Figure 2 could be smaller. There is little information and the figure is three-quarters of a page long. 

line 311: Were the increases the same for both methods? 

The authors should discuss the directions for future research in detail.

Author Response

The manuscript contains very interesting and useful data that can be of great practical importance. The Introduction provides sufficient background and includes the relevant references. The methods are adequately described.

Dear reviewer, thank you very much for your useful comments which have aid to improve our original manuscript. Below you can find an itemed list of your comments and suggestions and the answer and modification performed in the revised manuscript according to your suggestions. The new information added to the revised manuscript has been highlighted in pink ink.

lines 82, 83: The abbreviations 'CWI' and 'SAI' should be explained.

Done as suggested. Please, see lines 85-86.

lines 84-89: What is the novelty of the present research compared to previous literature data with regard to the influence of bunch compactness and berry thinning on grape quality? Was only the cultivar different or were the methods of bunch compactness and berry thinning different?

The investigations and results embodied in this research article are, to date, unique for the following reasons:

- Nothing has been published regarding the incidence that bunch compactness and berry thinning has on wines obtained from the Monastrell grape.

- Even though there are already other articles published following the same line of research, which have been cited in this manuscript, they use different grape cultivars and are cultivated in climates, soils, cultural conditions, etc., different from those shown here.

- Until now, the effect that these techniques (bunch compactness and berry thinning) have on the sensory properties of the wines produced has not been studied. The literature only collects the incidence on physical-chemical properties, but not how (really) it affects the product itself sensorially. We must not forget that bunch compactness and berry thinning are designed to obtain a product with higher organoleptic quality and only sensory analysis can guarantee this.

line 114: Is there other way than manual?

We really do not know of any other way to carry out this type of treatment, but we believe that the inclusion of this clarification in that line is necessary to make the reader aware of the difficulty of the technique.

lines 271-272: Why did the authors not show the data? 

Sorry for the mistake. In fact, the data is described in the results section and is further discussed later. The sentence ‘data not shown’ has been removed from the entire manuscript to avoid confusion in the reader.

line 293: It has been written '(data not shown)'. What data has not been shown?

Similarly, the data is described in the results section and is further discussed later. The sentence ‘data not shown’ has been removed from the entire manuscript to avoid confusion in the reader.

Table 2: What did 'control' mean? Was it 'compact bunch' like in Table 1?

Yes, ‘control’ in the second experiment means ‘compact bunch’ as the first experiment. This clarification has been included in the material and methods section, according your suggestion. Please, see line 116.

Figure 2 could be smaller. There is little information and the figure is three-quarters of a page long.

Thank you for this suggestion. Figure 2 has been modified in order to reduce its final size. Please, see line 321.

line 311: Were the increases the same for both methods?

Statistically, yes, as can be seen in Figure 2. Both methods had statistically equal results with respect to the control treatment related to functional parameters. However, this clarification has been detailed in the results section. Please, see line 320.

The authors should discuss the directions for future research in detail.

Thanks for your kind comment. At the end of the conclusions, a brief paragraph has been added in which we indicate the future lines of research that are being worked on. Please, see lines 492-495.

Reviewer 2 Report

The manuscript entitled “Influence of Bunch Compactness and Berry Thinning Methods on Wine Grape Quality and Sensory Attributes of Wine in Vitis vinifera L. cv. 'Monastrell' ”is an interesting one because it addresses a subject not studied, or very little studied: berry thinning methods led to wines with greater sensory descriptors, such as fruity (smell and flavor), sour, sweet, aftertaste and color, and were the most favorite by consumers.
The abstract is very well organized and detailed
Introduction can be improved with some information:
general information about Compactness is missing
Please detail the results listed on line 82-88
Existing studies on all the analyzes mentioned in your manuscript
Materials and Methods - are detailed accordingly
3. Results
Table 1 - incomplete statistical analysis
Given that the data in the literature are scarce, the study is fairly well discussed

Author Response

The manuscript entitled “Influence of Bunch Compactness and Berry Thinning Methods on Wine Grape Quality and Sensory Attributes of Wine in Vitis vinifera L. cv. 'Monastrell'” is an interesting one because it addresses a subject not studied, or very little studied: berry thinning methods led to wines with greater sensory descriptors, such as fruity (smell and flavor), sour, sweet, aftertaste and color, and were the most favorite by consumers.
The abstract is very well organized and detailed.

Dear reviewer, thank you very much for your useful comments which have aid to improve our original manuscript. Below you can find an itemed list of your comments and suggestions and the answer and modification performed in the revised manuscript according to your suggestions. The new information added to the revised manuscript has been highlighted in blue ink.

Introduction can be improved with some information: General information about Compactness is missing.

According to your suggestion, we have rewritten the part of the introduction that mentions this term. Please, see lines 53-64.

Please detail the results listed on line 82-88.

Done as suggested. It has been expanded with a sentence in which the conclusion that the authors gave is stated and in which the main objective of this study is based. Also, thanks to reviewer feedback, we have corrected the abbreviations in this section. Please, see lines 84-88.

Table 1 - incomplete statistical analysis

Reviewer is right. We have included the statistical information regarding the results obtained after the student’s t test. Please, see Table 1 (lines 289-294).

Existing studies on all the analyzes mentioned in your manuscript. Given that the data in the literature are scarce, the study is fairly well discussed.

Thank you very much for your comment. We really appreciate it.

Reviewer 3 Report

English language and style, grammar and vocabulary must be thoroughly revised. Some examples:

• Wrong abstract start with "As far as we know"
• Line 21, abstract: "both berry thinning methods promoted the accumulation of total anthocyanins content in berries" must be reworded as "... promoted the increase of anthocyanin concentration..." or similar
• The use of the word "method" related to the thinning extent must be avoided or clarified
• Line 24: "most favourite" is an incorrect expression
• Sentences that must be reworded (just some examples, not an exhaustive list):
  • Line 54 "These types of bunches are susceptible to Botrytis bunch rot and a higher number of internal berries."
  • Line 67: Several authors have been studied the influence of bunch thinning on wine grape ripening as well as on wine composition and quality [17-23].
  • Paragraph starting at line 75 must be revised.
  • Line 128: All the grapes from each replicate per treatment were mixed together after weighing, the bunch characterization, physico-chemical and functional determinations performed so as to obtain more homogeneous samples for winemaking.
  • Line 205: "All microvinifications were controlled daily by analyzing the temperature and density of juice samples every day to control for delays or stoppages in the fermentation process." Wrong use of "analysing" instead of "measuring", redundance with "daily" and "every day"
  • Line 275: "As expected, the total yield per grapevine of non-compact bunch group were significantly reduced" "was" must be used instead "were"
  • Line 281: "Related to physico-chemical parameters, wine grapes from non-compact bunches accumulated significantly more content of TSS than compact ones (Table 1)." wrong use of "accumulated" with "content of"
  • Line 347: wrong use of "On the other hand"
  • Line 379: "Regarding  bunch  characterization,  bunch compactness  was  obviously  decreased  in both  growing seasons  in  non-compact  bunches  group  and  by  removing  25 %  and  50 %  of berries  in  each  bunch  of  ‘Monastrell’  wine  grape  than  the  compact  or  control  ones, respectively  (Figure  1)." "Than" used without comparison. Avoid overwording, too much words to say that the removal of berries or non-compact bunches leads to a compactness decrease, that is just an obvius thing.
  • Line 392: "Other previous studies on bunch compactness report that each of berries has more ": "each of berries"?
  • Line 425: "...namely total phenolics and total anthocyanins, was improved after reducing the bunch compactness": increased should be used instead "improved"
  • Line 493: "with different wine grape cultivars and in those areas with different edaphoclimatic": remove "those" 

Bibliography used in the experimental section must be revised as it's unncesary or redundant. There are routine methods that are wrongly referenced.

Table 1: redundant information about the Student test (a table column with * and NS and the use of letters)

Figure 2 can be removed and the resultas can be included in table 2

Section 3.4 (PCA) must be justified and it lacks a proper description both of the obtained results and its significance  

Table 3:

• Results without SE or deviations, if 0 must be stated.
• Overall ranking values? How is it possible to stablish that there are siginificant differences without results?
• Use of letters to denote differences based on Tukey's test is not clear. 
• There is a lack of consistency between differences that are taken as significant while other (greater tha the former) are not.

Discussion section: sentence2 starting in line 430 and 447 and following ones should be included in the introduction section. Afterwards, if pertinent, the comparison can be made in the discussion section.

Section 5: first sentence "In conclusion, both experiments in two growing seasons (2018 and 2019); 1) compact and non-compact bunches and 2) control and 15 % and 50 % berry thinning methods, respectively" not clear...

Section 5: "show a reduction of total yield, bunch compactness and bunch fresh mass. " that shouldn't be treated as a result as is just the logical consequence of reducing the number of grapes.

Author Response

Dear reviewer, thank you very much for your useful comments which have aid to improve our original manuscript. Below you can find an itemed list of your comments and suggestions and the answer and modification performed in the revised manuscript according to your suggestions. The new information added to the revised manuscript has been highlighted in green ink.

English language and style, grammar and vocabulary must be thoroughly revised. Some examples:

• Wrong abstract starts with "As far as we know".

RESPONSE: The beginning of the abstract has been changed according to your suggestions (line 13).

• Line 21, abstract: "both berry thinning methods promoted the accumulation of total anthocyanins content in berries" must be reworded as "... promoted the increase of anthocyanin concentration..." or similar.

RESPONSE: The sentence has been rephrased according to your suggestions (line 21-22).

• The use of the word "method" related to the thinning extent must be avoided or clarified.

RESPONSE: We think that the use of the word ‘method’ is necessary in order to reference this agronomic technique (berry thinning) along the manuscript. In this sense, the meaning of this method has been clarified according to your suggestions (line 16, 81, 102 and 124). In the same way, the use of this word has been reduced throughout the manuscript according to this comment. Other authors have also referenced thinning methods in table grapes, as you can see below:

Domingos, S.; Nobrega, H.; Raposo, A.; Cardoso, V.; Soares, I.; Ramalho, J.C.; Leitão, A.E.; Oliveira, C.M.; Goulao, L.F. Light management and gibberellic acid spraying as thinning methods in seedless table grapes (Vitis vinifera L.): Cultivar responses and effects on the fruit quality. Sci. Hortic. 2016, 201, 68-77. DOI: 10.1016/j.scienta.2016.01.034.

• Line 24: "most favourite" is an incorrect expression.

RESPONSE: It has been changed by ‘the preferred by consumers’ (line 24).

Sentences that must be reworded (just some examples, not an exhaustive list):

• Line 54 "These types of bunches are susceptible to Botrytis bunch rot and a higher number of internal berries".

RESPONSE: It has been rephrased, as follows: ‘These compact bunches are highly susceptible to Botrytis incidence due to their high number of internal berries’ (line 54-55).

• Line 67: Several authors have been studied the influence of bunch thinning on wine grape ripening as well as on wine composition and quality [17-23].

RESPONSE: It has been rephrased, as follows: ‘Several authors have studied’ (line 69).

• Paragraph starting at line 75 must be revised.

RESPONSE: It has been rephrased, as follows: ‘Berry thinning is an alternative method to the traditional one of bunch thinning in order to improve wine grape ripening [7]. This agronomic practice consists on the removal of the tips of all the bunches once the flowering has started to obtain blunted bunches of grapes. This can be linked with some previous studies where a higher wine grape quality was observed and an earlier ripening can be reached in berries from the shoulders and top of the bunch rather than from the tips [31,32]. Liu et al. [33] reported that the use of berry thinning for the reduction of bunch compactness greater increase of sugar and anthocyanin content than bunch thinning in ‘Cabernet Sauvignon’ cultivar, according to a previous study [34]. Recently, Han et al. [35] have elucidated that berry thinning significantly in-creases the accumulation of berry sugars in this cultivar throughout the up-regulation of cell wall invertase (CWI) activity, a key regulator of the carbon partitioning during berry ripening, or the cooperation with soluble acid invertase (SAI) to control sink strength of the remaining berries in response to berry removing. These mechanisms suggested that reducing bunch compactness might change the chemical composition of the wine obtained. Although some scientific articles discuss the influence of bunch compactness and berry thinning on grape ripening, to our knowledge they are all focus on table grapes [36,37] or in ‘Syrah’ and ‘Cabernet Sauvignon’ wine grape cultivars [7,35]. None of them have studied the influence of these practices on the wine grape quality in ‘Monastrell’ cultivar’ (line 81-98).

• Line 128: All the grapes from each replicate per treatment were mixed together after weighing, the bunch characterization, physico-chemical and functional determinations performed so as to obtain more homogeneous samples for winemaking.

RESPONSE: It has been rephrased, as follows: ‘The grapes of the three replicates from each method were mixed once they were weighed, bunch and the physico-chemical and functional characterized in order to obtain more homogeneous samples for winemaking’ (line 135-137).

• Line 205: "All microvinifications were controlled daily by analysing the temperature and density of juice samples every day to control for delays or stoppages in the fermentation process." Wrong use of "analysing" instead of "measuring", redundance with "daily" and "every day".

RESPONSE: It has been rephrased, as follows: ‘All microvinifications were controlled daily by measuring the temperature and density of juice samples to control the delays or stoppages in the fermentation process’ (line 210-212).

• Line 275: "As expected, the total yield per grapevine of non-compact bunch group were significantly reduced" "was" must be used instead "were".

RESPONSE: It has been rephrased, as follows: ‘As expected, the total yield per grapevine of non-compact bunch group was significantly reduced’ (line 281-282).

• Line 281: "Related to physico-chemical parameters, wine grapes from non-compact bunches accumulated significantly more content of TSS than compact ones (Table 1)." wrong use of "accumulated" with "content of".

RESPONSE: It has been rephrased, as follows: ‘Related to physico-chemical parameters, wine grapes from non-compact bunches increased significantly its content of TSS than compact ones (Table 1)’ (line 286-287).

• Line 347: wrong use of "On the other hand".

RESPONSE: It has been changed by ‘Furthermore’ (line 349).

• Line 379: "Regarding bunch characterization, bunch compactness was obviously decreased in both growing seasons in non-compact bunches group and by removing 25 % and 50 % of berries in each bunch of ‘Monastrell’ wine grape than the compact or control ones, respectively (Figure 1)". "Than" used without comparison. Avoid overwording, too much words to say that the removal of berries or non-compact bunches leads to a compactness decrease, that is just an obvious thing.

RESPONSE: It has been rephrased, as follows: ‘The bunch compactness showed a higher decrease in both growing seasons in non-compact bunches group and those where the berry thinning method was applied compared to compact or control ones, respectively (Figure 1)’ (line 390-392).

• Line 392: "Other previous studies on bunch compactness report that each of berries has more ": "each of berries"?

RESPONSE: It has been rephrased, as follows: ‘report that berries have more’ (line 402).

• Line 425: "...namely total phenolics and total anthocyanins, was improved after reducing the bunch compactness": increased should be used instead "improved".

RESPONSE: It has been rephrased, as follows: ‘On the other hand, the content of bioactive compounds, namely total phenolics and total anthocyanins, increased after reducing the bunch compactness of ‘Monastrell’ wine grape (Table 1 and Figure 2)’ (line 434-436).

• Line 493: "with different wine grape cultivars and in those areas with different edaphoclimatic": remove "those".

RESPONSE: It has been rephrased, as follows: ‘with different wine grape cultivars and in areas with different edaphoclimatic properties’ (line 494-495).

Bibliography used in the experimental section must be revised as it's unnecessary or redundant. There are routine methods that are wrongly referenced.

RESPONSE: Bibliography used in the experimental design has been checked and some cites that were redundant or wrongly referenced have been removed. After this change, all the numbers of references have been updated along the manuscript.

Table 1: redundant information about the student test (a table column with * and NS and the use of letters).

RESPONSE: Table 1 has been checked and the use of letters has been removed according to your suggestions. Significant differences between both methods are expressed as * symbol or NS (not significant) (line 293).

Figure 2 can be removed and the results can be included in table 2.

RESPONSE: We think that Figure 2 is essential to show the significant differences among the methods studied on bioactive compounds content, since these differences are more visual and direct to the reader if they are reflected in graphic format. In addition, there is not much information about the effect of this agronomic method on the antioxidant content of berries, thus, this figure reflects an importance of the main aim of this study. Finally, the format of this figure was previously changed according to the comments or suggestions of reviewer 2.

Section 3.4 (PCA) must be justified and it lacks a proper description both of the obtained results and its significance.

RESPONSE: These types of representations are normally used to group all the results in which statistically significant differences have been detected. The resulting graphic representation allows simplifying the differences obtained and having a global vision in an easy and direct way. Therefore, we do not consider that it should be explained in detail since the results have already been explained in its specific section. Following your suggestion, we have expanded the description of the test so that the reason for its presence in the manuscript can be better understood. Please, see section 3.4 (line 355-370).

Table 3:

Results without SE or deviations, if 0 must be stated.

RESPONSE: The results obtained in this article have been treated according to the analysis of the variance (ANOVA) and Tukey’s multiple range test, which consider the standard deviation when grouping the samples. The inclusion of the standard errors will only make tables more difficult to follow. Especially in the tables that show sensory analysis results, since many descriptors (variables) are used. Thus, this information is already implicitly included in the statistical analysis carried out. In this type of tables, the absence of deviations is normalized. You can see examples in articles published in different journals and/or publishers. For example:

• Carbonell-Barrachina, A.A., et al., (2015). doi:10.1002/jsfa.7027
• Galindo, A., et al., (2015). doi:10.1016/j.lwt.2015.04.055
• Issa-Issa, H., et al., (2019). doi:10.1155/2019/5981762
• Navarro-Martínez, P., et al., (2019). doi:10.1007/s00217-018-3138-9
• Noguera-Artiaga, L., et al., (2020). doi:10.3390/foods9020158
• Zapata, P.J., et al., (2019). doi:10.1016/j.lwt.2019.01.002

Overall ranking values? How is it possible to stablish that there are significant differences without results?

RESPONSE: The ranking data is obtained through the statistical treatment of the Friedman's test. The panellists order the samples according to their preference (if there are 3 samples, they score 1 point as the most preferred, 2 the next and 3 the least preferred). Subsequently, a sum of ranges is performed and a comparison of the differences between the ranges is made against the statistical value tabulated according to the number of judges/samples.

Due to the way this test works, the results would be complex to understand, since sums of ranges would be compared, and it could confuse the reader by having different scales in the same table. This type of expression of results is very common when expressing sensory data. You can see an example in a previous published study:

• Issa-Issa, H., et al., (2019). doi:10.1155/2019/5981762

Use of letters to denote differences based on Tukey's test is not clear. There is a lack of consistency between differences that are taken as significant while other (greater than the former) are not.

RESPONSE: It is quite normal for this to occur in a descriptive sensory analysis panel. In some sensory descriptors, due to their complexity, the variabilities between the judges' scores are greater than in other descriptors. When we deal with sensory data, we must be aware that on a 21-point scale, such as the one used in this study (0 minimum intensity, 10 maximum intensity, using intervals of 0.5 points) the perceptions of the judges can oscillate in several units in complex attributes (as infrequent odours), so it is normal that in this type of attributes there are differences between the means/medians of the panel but that they are not consistent enough to be considered statistically.

All data are analyzed using ANOVA and Tukey's multiple range test.

After your suggestion, we have contrasted all the results and have detected an error in the acidity descriptor (sour) that has been corrected. Please check table 3 (line 339).

Discussion section: sentence 2 starting in line 430 and 447 and following ones should be included in the introduction section. Afterwards, if pertinent, the comparison can be made in the discussion section.

RESPONSE: Both sentences have been included in the introduction section, according to your suggestion. Please, see line 60-62 and line 70-74.

Section 5: first sentence "In conclusion, both experiments in two growing seasons (2018 and 2019); 1) compact and non-compact bunches and 2) control and 15 % and 50 % berry thinning methods, respectively" not clear...

RESPONSE: It has been rephrased, as follows: ‘In conclusion, non-compact bunches (2018 season) and the 15 % and 50 % berry thinning methods (2019 season) show a reduction of total yield, bunch compactness and bunch fresh mass compared to compact and control ones, respectively’ (line 478-480).

Section 5: "show a reduction of total yield, bunch compactness and bunch fresh mass. " That shouldn't be treated as a result as is just the logical consequence of reducing the number of grapes.

RESPONSE: It is right, but we honestly believe that it should be treated as a result, since removing berries from the bunch may cause the remaining ones to grow more than expected, taking advantage of the available resources, and no significant differences can be seen in terms of yield or production. Thus, fewer berries but the same production because the size increases. This has not been the case in our study, which is why we express it as a result. A previous published study also includes this agronomic parameter as a result. Please, see this reference:

Gil, M.; Esteruelas, M.; González, E.; Kontoudakis, N.; Jiménez, J.; Fort, F.; Canals, J.M.; Hermosín-Gutiérrez, I.; Zamora, F. Effect of two different treatments for reducing grape yield in Vitis vinifera cv Syrah on wine composition and quality: berry thinning versus cluster thinning. J. Agric. Food Chem. 2013, 61, 4968-4978. DOI: 10.1021/jf400722z

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

All suggestions have been correctly answered and discussed correcly.