Effects of Berry Thinning on the Physicochemical, Aromatic, and Sensory Properties of Shine Muscat Grapes

Round 1

Reviewer 1 Report

Please see attached file.

Comments for author File: Comments.pdf

Author Response

Reviewer 1

1. Please mention what the treatments were.
As suggested by the reviewer, detailed treatment has been described in the revised manuscript (Line 16)

2. Origin of ‘Shine Muscat’
As suggested by the reviewer, a reference on the origin of the 'Shine Muscat' cultivar has been added and the others were revised sequentially in the revised manuscript (Lines 36 and 362-364).

3. Just distribute this information into other sections as necessary/ where appropriate, unless editorial policy dictates otherwise.
As suggested by the reviewer, Section 2.1 has been deleted in the revised manuscript. The information on the reagents used are available in reference papers.

4. Suggest move sections 2.2 and 2.3 before the section 2.1 Materials.
As suggested by the reviewer, Section 2.2 and 2.3 has been changed into 2.1 and 2.2, respectively, in the revised manuscript.

5. It appears that this whole paper is based upon 1 yr. of data. It is also unclear what the experimental design was--how many vines, how many replicates, etc.
As suggested by the reviewer, additional statement on the thinning treatment has been added in section 2.1 in the revised manuscript (Line 72-74 and 77).
There are many preceding reports on the effects of thinning treatments on the fruit quality of grapes (Jung et al. Korean J. Food Preserv. 2010, 17, 625-630; Pastore et al. BMC Genomics 2011, 12, 631). So, a year’s worth of data may be enough to evaluate the effects of berry thinning on the quality of Shine Muscat grapes.

6. Soluble solids--correct this as appropriate throughout the paper
As suggested by the reviewer, "soluble solid" has been changed into "soluble solids" throughout the revised manuscript

7. Delete this formula--it is widely known.
As suggested by the reviewer, the equation has been deleted in the revised manuscript 

8. Please use "concentration" instead of "content(s)" throughout the manuscript.
As suggested by the reviewer, "content(s)” has been replaced with "concentration" throughout the revised manuscript.

9. All this information could be incorporated into Table 3 with addition of just one more column; then, this table could be deleted. Text callouts would need necessary adjustment.
As suggested by the reviewer, Table 1 has been deleted and the information have been inserted in Table 2 in the revised manuscript (Line 284).

10. There does not appear to be any training involved with this panel. Could they all identify muscat flavor? Were any anosmic to any degree? What was the nature of the training?
As indicated in the text people who were familiar with muscat flavor were recruited for the test. Also, they were tested whether they could perceive the intensity of muscat flavor using linalool, hexanal, and hexanol standards with different concentrations before the test. Additional statement has been inserted in the revised manuscript (Line 183-186)

11. "significant(ly)" is a scientific redundancy and can be deleted everywhere. Just say "they were different"
As suggested by the reviewer, "significantly" has been deleted throughout the revised manuscript

12. Are these in ug/L? Specify units please.
Please check the footnote below the table. The unit was already indicated (Line 287).

13. These "subtotal" lines throughout the table can probably be deleted.
As suggested by the reviewer, “subtotal” has been deleted throughout Table 2 in the revised manuscript (Line 284).

14. This figure is not necessary and serves very little in terms of improving the paper. Please delete.
As suggested by the reviewer, Figure 5 has been deleted in the revised manuscript.

15. Whether compounds were above threshold may be irrelevant if you have not evaluated any aroma characteristics sensorially.
We agree with the reviewer’s opinion. Odor activity value is possibly irrelevant to sensory perception because flavor can be affected by various factors including other sensory parameters, berry composition, and synergistic effects of other aroma compounds. However, we should remember the definition of an odor threshold value. This value is the lowest concentration of a certain aroma compound that is perceived by the human nose. From the definition, it is inferred that an aroma compound with higher odor activity value can be an influential component responsible for overall flavor of grape samples rather than the others. In the present manuscript, linalool and linalool oxide were only monoterpenes with OAV higher than 1. Also, the increasing trend of their concentrations was similar with that of sensory score. Thus, thees results indicate that linalool and its derivative were the key aroma compounds affecting overall flavor of Shine Muscat grapes.

16. Others
Changes in the revised manuscript have been highlighted with red color.
Inappropriate words, sentences, and expressions in the text have been improved or corrected.

 

Reviewer 2 Report

Authors present a study presenting a comparison between two berry thinning procedures (30% and 50%) over control samples (grapes with no berry thinning - 0%).  Their findings contribute to the general knowledge in the field, by completing it with information on Shine Muscat variety (Vitis labruscana Baily x Vitis vinifera L). Information on thinning effects on berry size, cluster size, total soluble solids content, titratable acidity, as well as on chemical composition have been provided and interpreted, and several analytical instrumental techniques have been applied. 

I include herein few corrections that I suggest:

Section 1 - suggestion to add an argument on choosing the compositional parameters presented in  the study - i.e. why TPC, PAC and PTC have been chosen and not TPC only  - correlation with specific grape quality / characteristics; i.e. reason of the 36 standards choice for volatile aroma contents, etc.

Section 2. Few information are missing, in the idea that they have to be sufficient to reproduce the experiment

2.4.1. - specific data on skin sampling for further use are missing - i.e. lyophilization parameters (temperature, time, quantities, final moisture of samples etc), storage conditions of lyophilized samples, grinding parameters, etc.

2.4.4. - the incubation temperature mention is missing (2 times)

2.6. - the sensory assessment was performed with the "classic" seven-point scale method  - a reference should be included on this topic, so the one may read its application rules / details elsewhere

Section 3

3.1. - I suggest Fig. 1 to keep only one plot - as A plot and B plot, actually present the same experimental data (TSS and TA vs level of berry thinning)

3.3. - Table 3 - row C13 - Norisoprenoids - last column "N.D." missing;

Fig. 5 - OY axis (ion chromatograms plot) - the measured property needs to be mentioned, as well as its measurement unit   

Author Response

Reviewer 2

1. Section 1 suggestion to add an argument on choosing the compositional parameters presented in the study - i.e. why TPC, PAC and PTC have been chosen and not TPC only - correlation with specific grape quality / characteristics; i.e. reason of the 36 standards choice for volatile aroma contents, etc.

1) In many preceding studies, TPC have been used for quality assessment of grape varieties. However, phenolic compounds are structurally diverse. The structural diversity of phenolic compounds has important impacts on biological and organoleptic properties. Many previous studies indicated that polymeric tannin content strongly affects the astringent sensation of grapes and wines. Our previous study (https://doi.org/10.3390/app10228020) also indicated that polymeric tannin content was strongly correlated with the astringent sensation of wines. While monomeric and oligomeric tannins (proanthocyanidins) are known to give bitterness rather than astringency. Thus, we analyzed PTC and PAC separately from TPC to observe their impacts on the sensory properties since they could affect the eating quality of Shine Muscat grapes. Additional statement has been inserted in the revised manuscript (Line 252-255).

2) We analyzed 66 standards but picked up only 36 because only 36 standards were identified in the grape samples.

2. Section 2. Few information are missing, in the idea that they have to be sufficient to reproduce the experiment
1) 2.4.1. specific data on skin sampling for further use are missing - i.e. lyophilization parameters (temperature, time, quantities, final moisture of samples etc), storage conditions of lyophilized samples, grinding parameters, etc.

As suggested by the reviewer, the experimental procedures for the lyophilization and storage have been described in the revised manuscript (Line 104-107).

2) 2.4.4. the incubation temperature mention is missing (2 times)

As suggested by the reviewer, the incubation temperatures have been inserted in the revised manuscript (Line 136, 140, and 143).

3) 2.6. the sensory assessment was performed with the "classic" seven-point scale method - a reference should be included on this topic, so the one may read its application rules / details elsewhere

As suggested by the reviewer, a relevant reference has been inserted in the revised manuscript (Line 191)

3. Section 3
1) 3.1. I suggest Fig. 1 to keep only one plot - as A plot and B plot, actually present the same experimental data (TSS and TA vs level of berry thinning)

As suggested by the reviewer, the plot a and b were merged into one plot in Figure 2 in the revised manuscript (Line 232).

2) 3.3. Table 3 - row C13 - Norisoprenoids - last column "N.D." missing;

As suggested by the reviewer, “N.D” was inserted in the last column of row C13-Norisoprenoids (Lin 284).

3) Fig. 5 OY axis (ion chromatograms plot) - the measured property needs to be mentioned, as well as its measurement unit 

One of the reviewers suggested to delete Figure 5 (TIC chromatogram plot) because it has no or little effect on improving the manuscript quality. We agreed with the reviewer’s opinion. So, Figure 5 has been deleted in the revised manuscript.

4. Others
1) Changes in the revised manuscript have been highlighted with red color.

2) Inappropriate words, sentences, and expressions in the text have been improved or corrected.

Reviewer 3 Report

The effect of berry thinning on fruit taste and aroma metabolites, as well as sensory properties of Shine Muscat grapes has been clearly described. There are, however, parts that need more clarification.

 1)  Authors should provide details on how the thinning percentage is calculated. 

 2)  Color coordination has not been explained, neither in MM nor in the result section. What do the letters in table 2 indicate? 

Author Response

Reviewer 3

1.  Authors should provide details on how the thinning percentage is calculated. 

After fruit setting, each cluster usually has 80-90 fruitlets left. 70% and 50% of the berries in the cluster were left for each treatment, and the rest were removed. Additional statement has been added in section 2.1 in the revised manuscript (Line 72-74 and 77).

 2. Color coordination has not been explained, neither in MM nor in the result section. What do the letters in table 2 indicate? 

The color coordinates L, a, and b indicate perceptual lightness, greenness, and yellowness, respectively. Additional statement was inserted in section 2.2 in the revised manuscript (Line 98-100)

3. Others
1) Changes in the revised manuscript have been highlighted with red color.
2) Inappropriate words, sentences, and expressions in the text have been improved or corrected.