Potential Use of Grape Stems and Pomaces from Two Red Grapevine Cultivars as Source of Oligosaccharides
, Rita Simões 2, Helena Pereira 2, Sofia Catarino 1,3, Jorge Ricardo-da-Silva 1, Isabel Miranda 2 and Suzana Ferreira-Dias 1,*Round 1
Reviewer 1 Report
Overall, the work presented in this paper is interesting because of the reliable analysis. This manuscript was recommended to be accepted as it is.
Author Response
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Author Response.pdf
Reviewer 2 Report
Congratulations for this work. For future research I recommend to you to use more types of grapes/leftovers. You research is very useful for the food industry and for circular economy and more studies are necessaries in future.
Author Response
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Reviewer 3 Report
The manuscript entitled "Potential use of grape stems and pomaces from two red grape vine cultivars as source of oligosaccharides" by Mangione et al. describes and discusses interesting aspects associated with the variables influencing the process of autohydrolysis of hemicelluloses from stems and pomaces of red grape cultivars Touriga Nacional and Marselan. However, some aspects need to be improved before publishing your manuscript.
In my view, the main weakness of the study is that the conclusions drawn are not necessarily based (or at least not described as such) on statistical analyses to support comparisons between cultivars (Touriga Nacional and Marselan) and between by-pruduct types (stems and pomaces).
If we add to this the fact that the authors modify variables associated with the extraction process and compare their effects, this results in a large amount of data that can be better analysed. It would perhaps be appropriate to choose only one cultivar and look more closely at the effects of extraction parameters, comparing between stems and pomaces.
Introduction
Line 65. References should be associated with this sentence: "The interest in new prebiotics such as xylo-oligosaccharides (XOS) is increasing in recent years". It is suggested to indicate the reasons for the increased interest described.
Line 80. The authors intend to evaluate factors influencing autohydrolysis in the red grape cultivars Touriga Nacional and Marselan, but do not indicate why they use two cultivars. It is suggested to justify the rationale of including and comparing these two cultivars.
Materials and Methods
In general, it is suggested to make the description of materials and methods neater, e.g., to homogenize the spaces between numerical values and units (at least three different ways of describing temperatures -18°, 60°_C, 105°C).
Line 188: In brief, 100 ?L of hydrolysate solution. There is a decoding error.
Results and Discussion
Line 213 -215: The total content of extractives was very high and similar in both pomace samples: 63.9% of the of Marselan and 64.4% of the Touriga Nacional pomaces. In order to make the description of the results more precise, I suggest writing in the description of the results the same figures as in the tables, not approximations. More importantly, I suggest avoiding the use of adjectives and to rely on what the statistical analyses indicate.
Throughout the study, no statistical analyses are described or observed. This is of particular concern in Table 2 and 3, which shows the results obtained for both cultivars. Statistical analyses to differentiate the results obtained between pomace and stems are also not described.
Were the results shown in table 3 and 4 performed only once? No replications? I ask because a number with no variance is shown.
Author Response
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Reviewer 4 Report
The article is well prepared and contains original aspects relevant to current research and practical interest.
I only make comments regarding statistical methods.
The paper lacked information regarding the statistical methods used. There is no information on whether the mean values presented in the tables are statistically significantly different. Whether the coefficients in the regression equations are statistically significant.
Author Response
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