Impact of Solvent Type on Total Phenol and Flavonoid Content and Sun Protection Factor of Crude Cashew Nutshell Liquid
Round 1
Reviewer 1 Report
General overview.
Manuscript Suschem-1748776 titled “IMPACT OF SOLVENTS ON THE TOTAL PHENOL, FLAVONOID CONTENT, AND SUN PROTECTION FACTOR OF CRUDE CASHEW NUTSHELL LIQUID”, studied the extractability of specific compounds from crude cashew nutshell liquid. In general introduction is easy to read but the aim is very compressed. The methods should be improved, and statistical analyses is not appropriate. Regarding results and discussions need of same explanation. Are you sure that phenolic lipids are more soluble in polar solvent?? In addition, no discussion was reported about the chemical nature of the matrix that in my opinion, significantly affect the extraction in relation to the solvent. Finally, the conclusion should be enriched.
The real limits of this studies are mainly due to the experimental design, no optimization of the extraction parameters was made in relation to the different solvent used. The extraction was made without taking into account the sonication time, temperature energy. In addition statistical are you sure that statistical result (correlation) is not influenced by the dataset size? In my opinion strong revision and other data derived from more rice sample are need before to publication
Major comments.
1- The aim of the work is very poor. In addition I suggest to add the potential application of the obtained results.
2- The Material and methods sometime appear incomplete. No Information about sonication was reported and no explanation about how the authors establish the optimal extraction parameters was found. Please add information.
3- The results and discussion should be enriched considering the matrix effects respect to the compound extraction in relation to the solvent. I suggest adding more consideration about the matrix effect, the sonication treatment etc. In addition are you sure that colorimetric test allow a correct evaluation of the compounds? Different solvent could be coextract different substances not necessarily belonging to the families analyzed that could be affected the real quantification. In my opinion curve calibration and correlation graph should be deleted because the curve calibration is superfluous, and correlation is not applicable on your dataset (5 data). I suggest that you completely review the statistical calculations with more appropriate algorithm.
4- I suggest adding a possible application of these extracts highlight the vantage and disadvantage respect to another matrix.
Minor comments.
Line 10-21 define the acronyms before to use
Line 12 Percentage is not in international measure unit system
Line 12 to all text and table check the number of significant digits (ie 30.38 ± 0.73 should be reported as 30.4 ± 0.7)
Line 106 is not clear when the authors use rotavapors
Line 106-107 add information about instrument (brand, model etc)
Line 120 add information about sonication setting (temperature, frequencies etc) and how the authors defined those were the optimal conditions
Line 123 the second extraction was made without sonications???
Line 141 delete (SHIMADZU 2600, model)
Line 146 TPC or TFC???
Line 153 delete (SHIMADZU 2600, model)
Table 2 add tests to evaluate the significance of the differences
Line 191 these sentence is not clear.
Line 213 delete point after GAE/g
In all text standardize acronyms of Gallic acid
Table 2 correlation coefficient on 5 data??? Delete correlation
Line 278 perimeters I think parameters
Line 279 poor composition??? I think low content
Author Response
Please see the attachement.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Thank you for your submission. My biggest criticism is that the discussion is a bit underwhelming, and I feel more could be done to understand the results and place them in context. Please concentrate on that, but also see my other suggestions (below).
1) There are too many acronyms in the abstract. Please state their meaning at first use if the acronym is necessary but otherwise try to avoid!
2) Lines 24-35. Please add citations to justify these statements.
3) Lines 38-40. Please correct this statement. The processing of biomass into chemicals is associated with GHG emissions (albeit offset to a degree by the renewable carbon content of the feedstock, at least in a cradle-to-gate scope).
4) Line 43. Change "human supply chain" to "human food supply chain".
5) Lines 54-55. I recommend changing "Non-edible vegetable oils have the exact chemical characteristics, as edible vegetable oils except they are not suitable for human consumption" because it raises the question why are they inedible if exactly the same? Of course they are not 100% exactly the same. Also, the first comma in that quote is unnecessary.
6) Lines 63-69. There are large (double?) spaces occurring between words in this passage that are unneeded.
7) Lines 72-75. This statement is too grandiose and inaccurate. I would say crude oil is much more versatile as a feedstock, and CNSL is in fact underutilized and irrelevant to many industries. Please focus only on the applications that are appropriate and would benefit from CNSL.
8) Line 112. 'Under' a shed, or 'in' a shed?
9) Line 125. I can't recommend evaporating the solvents in an oven. Can you simply say the samples were concentrated at 40 C until no more mass loss was observed?
10) Line 131. All equations should be numbered, but I think this equation is unnecessary. You could say the yield is based on the original CNS mass (and indicate if that is a dry mass or not). If you want to keep the equation, the numerator can be simplified to "mass of CNSL".
11) Section 2.7. There appears to be some sort of formatting error as I can see a '290' and a '320' under the main text. Have they escaped from the equation (which should be numbered)? Please check your original submission (it may be caused by the journal converting the file).
12) Lines 196-197. Please don't describe the solvents as strong. You could say 'strongly polar' but 'strong(ly) non-polar' doesn't make sense. Maybe just 'apolar' would suffice?
13) Section 3.2. Can you define GAE at the start of this section? You have written GA on line 217 - should this be GAE as well?
14) Data in Table 2. Maybe you could phrase the extraction results in terms of selectivity rather than trying to find a correlation with the absolute TPC and TFC values? I can see when TPC is low, TFC is higher, but it is not a perfect relationship. A solvent's preference to interact with flavanoids may lower the TPC that is extracted, and vice-versa.
15) Section 3.4: Can you comment on the suitability of the extracts as a sunscreen product? Presumably it will have to be formulated with other ingredients to make a final product, and so the SPF will decrease. Are there any hazards associated with CNSL (irritation, smell, etc.)? It seems safe to use (https://echa.europa.eu/substance-information/-/substanceinfo/100.113.432)
16) There is no section 4. Conclusion should be section 4.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
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