Optimized Isolation and Characterization of the Major Polysaccharide from Grape Pomace
Round 1
Reviewer 1 Report
Dear editor and authors
After to review the manuscript entitled “Optimized Isolation and Characterization of The Major Poly-saccharide from Grape Pomace”. The optimization process to obtain polysaccharide is interesting and have many applications in several industries. There are other studies focused on the same aspect. Here are some of the suggestions or questions regarding this work.
Subtheme 2.2, page 68. Indicates samples was refluxed, but not specifies how it was done? In a flask or a reflux system? It is not clear.
Pages 68-69, what material was collected?
Pages 71-72, here is described obtention of GPP content in the samples, but indicates the use of 90 °C, solvent ratio 1:25 and time of 30 minutes, but below specifies that optimize those parameters.
Subtheme 2.4 pages 97-102, orthogonal test usually use treatment optimize not experiment.
Subtheme 3.1. what is the reason to test firstly single parameters? Because the orthogonal test is designed to optimize many parameters in one process.
Subtheme 3.2 page 192. Indicates statistical software, however in the point of 2.7 only indicates a one-way ANOVA test using SPSS software.
Fig 2A is axis x indicates elution time?
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The Idea of the research were clear and simple, and the research design was smart. Modern techniques were used in the best fit. Looking forward in next work for possible applications of the GPP.
Author Response
We appreciate this reviewer for such positive comments!
Reviewer 3 Report
Reviewer comments
In this work, Meng et al. optimised and characterised polysaccharides extracted from the pomace of grape using some spectroscopic approaches. Kindly, find below my comments for your response.
Introduction
Line 42: The authors should kindly indicate the material source from which the polysaccharides are obtained from
Line 44: This should begin as a new paragraph
Line 56-58: Please, revise the sentence
Materials and Method
Line 65: what type of drying was carried out? Was the pomace freeze-dried or oven dried?
Line 69: What type of temperature and time conditions was the oven-drying done?
Line 72: Why was this “1:25 for 30 min” selected?
Line 89: Why would the authors use a ratio different from that in Line 86?
Line 192: What was the statistical software that was used?
Line 105: How was the treatment done?
Line 106: How was the pH practically adjusted? Was it by treating it with ammonia gas? How was it done? Did the authors prepare a buffer for the pomace?
Fig. 1. The authors should expand the abbreviation GPP as Tables must stand alone
Table 2. The authors should kindly define K1, K2, K3 and R
Looking at Table 2, Experiment number 4 gave the highest yield of the GPP. That had the variables (2, 1 and 2). This represents a (ratio of material to solvent of 1:30, extraction temperature of 65 and extraction time of 40 minutes). However, the authors have indicated that, the raw material to solvent ratio was 1:25, extraction temperature was 75°C, and extraction time was 40 min as the most optimized variables. Yet, from Table 2, this combination gives the variables (1, 3 and 2) which hasn’t got any corresponding yield from Table 2. Even though the authors have indicated that by combining the K values, the optimal combination of variables would be the A1B3C2, it would have been expedient for the authors to go to the lab to validate the suggestion from the statistical suggestion.
Line 124: How were the pellets produced? Through extrusion?
Line 126: Do the authors mean that the “sans” is “scans?”
Line 129: what was the volume of trifluoroacetic acid?
Results and Discussion
Line 160: The yield of 15.3% indicated there is not found in Table 2. Can the authors indicate where it is coming from?
In the Discussion, though the authors try and establish some plausible mechanisms behind the seemingly increased yield for some of the observations, it would have been great if the authors could compare the outcome with other extraction methods such as the use of ultrasound-extraction methods.
Line 219: The authors should expand the abbreviation “PMP”
The authors should add depth to discussion. For example, under this section “Monosaccharide composition of purified GPP”, the authors should highlight the implications of the monosaccharides that were detected in the polysaccharide. For example, they could indicate the effect of the sugars on the sensory attributes of the grapes.
General comments:
On what basis did the authors generate the extraction parameters? In most optimisation processes, ideally, the authors should have used a software such as Design expert for example in this kind of work. The software will generate the various experimental numbers in the form of runs. The authors will then need to go the lab and practically conduct the experiment. Results from the conducted experiment will then need to be loaded into the software and optimisation based on the outcome of interest of the authors will then be carried out. However, the authors used a different approach for this work. Can they please explain why their approach was used which differs from the generally known approach?
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
Thanks for making time to revise the manuscript. Though I am fine with the revision, I think it would have been appropriate if the authors indicated the page numbers and what exact revisions they made in their "response to authors comments" document. The authors putting out statement like "Thanks for your suggestions! It has been revised in the article" is not appropriate as it makes the reviewer have difficulties in finding where in the manuscript the exact revision was done.
