Variability in Anthocyanins, Phenolic Compounds and Antioxidant Capacity in the Tassels of Collected Waxy Corn Germplasm
and Bhalang Suriharn 1,2,*Round 1
Reviewer 1 Report
This manuscript involves valuable information, however I think authors misunderstand “chemotype” and data is insufficient to reach certain conclusion.
In my understanding, the word “chemotype: chemical phenotype” is used for chemically distinct derived differences in the composition of metabolites among morphologically indistinguishable individuals. Especially, it is often mentioned as for essential oil composition in herbs. Therefore, “chemotype” means qualitative difference and we don’t use this word for quantitative difference. Classification based on the quantitative characters such as content or capacity cannot be regarded as properly method. Difference of molecular species of phenols should be clarified for classification.
Phenols (including anthocyanins) work as reducing agent and scavenging activity is a result of interaction between enzyme and reducing agent. Phenolic content is often influenced environmental stress such as UV radiation or high temperature. Reproducibility should be examined for reaching conclusion as authors pointed out.
Table 1, 2, 3 and Figure 1 were described based on same data and look redundant.
Author Response
Dear Reviewer1,
The manuscript entitled "Variability in Anthocyanins, Phenolic Compounds and Antioxidant Capacity in the Tassel of Collected Waxy Corn Germplasm " was revised according to the comments and suggestions of the reviewers.
The authors respond to the reviewers point by point.
The authors also check for possible errors, and the errors were revised and indicated by red letter.
Yours Sincerely,
Bhalang
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments to the authors:
The focus of the study is valuable from the point of view that seeks the evaluation of the total phenolic and anthocyanin content, and the antioxidant capacity by TEAC and DPPH assays in the tassel among 50 waxy corn genotypes collected from different countries and also evaluating the influence of these factors on the rainy and dry seasons of collection.
In general, the paper is very well written and structured. The data were subjected to a good statistical analysis, drawing good conclusions.
Given the importance of such studies, the manuscript could be revised according to the following comments:
Abstract section
Page 1, line 26. Eliminate assay from line 25.
Page 1, line 26. Eliminate s from effect: “…Season (S) had small effect on …”.
Page 1, line 33. Include “s” in assay: “…DPPH· and TEAC assays…”.
Introduction section
Page 1, line 41-42. Please, rewrite the sentence as follows: “… in phenolic compounds and anthocyanins in kernels, cobs, silks, husks, and tassel [2,3].
Page 2, line 58. In abstract authors said that corn tassel is a valuable co-product. However, in introduction and another sections along the manuscript they wrote that tassel is a by-product from corn production. So, corn tassel is a by-product that can be used as a valuable co-product? Please, rewrite the sentence of the introduction/abstract section.
Page 2, line 83. “…, phenolic compounds…”.
Materials and methods section
Page 3, lines 94-95. For a better understanding of the following sentence, include prepositions:
“..Project, in the Plant Breeding Research Center for Sustainable Agriculture from Khon Kaen University (KKU) of Thailand…”.
Page 3, line 104. The city and country of the LCI Labscan co., Ltd. is placed in parentheses. Please, do the same with the other brands.
Page 3, lines 117-118. Please, modify the sentence for a better understanding: “Briefly, 10 mL of the acidified methanol solution [1% citric acid (CA) in 80% methanol (MeOH)] was added…”.
Page 3, line 120. The extraction solvent is the 1% citric acid in 80% methanol? If so, include in parentheses (extraction solution) after (MeOH) in page 3 line 118.
Page 3, line 123. Include the dilutions made in samples in order to measure the total anthocyanin content.
Page 3, line 126. Modify the sentence for the following:
“…The results were calculated with the following equation:”
Page 3, line 136. Include the units of 0.5.
Page 4, line 141. Modify the title of this section including the assays tested. “Antioxidant capacity by TEAC and DPPH assays”
Page 4, paragraph of lines 143-145. Including the mixture of the solution of the radical with that of the sample and in turn including in the same sentence the preparations of the solutions of the sample and the radical makes the paragraph confusing. Separate both preparations or use parentheses.
Page 4, line 149. Mixing instead of mixin.
Page 4, line 150-152. This part of the method is not clear. The purpose of measuring absorbance at 0.700 is not explained. You have to explain that at that absorbance the ABTS·+ solution is ready to work.
Page 4, line 151. Eliminate the units of absorbance, nm.
Page 4, lines 155-157. Trolox solutions and units sentences are best placed in a separate paragraph since they are common to both methods of antioxidant capacity.
Page 4, line 159. Place a comma after season.
Page 4, lines 166-167. Pearson correlation analysis was done with JMP Pro software? Please, specify the software used.
Results and discussion section
Page 5, lines 185-187. Could the authors explain why during the dry season there are more phenols and anthocyanins and therefore greater antioxidant power?.
Page 7, line 250. Anthocyanins instead of antohcyanins.
Page 7, lines 252-253. What do the authors mean by the fact that the corn varieties in cluster C are interesting extraction of phenolic compounds with contamination of anthocyanins?
Page 8, line 265. Varieties in cluster F and G are only suitable for the production of anthocyanins? TPC and antioxidant capacity are similar to E group, which are excellent for the production of phenolic compounds and antioxidants.
Author Response
Dear Reviewer2,
The manuscript entitled "Variability in Anthocyanins, Phenolic Compounds and Antioxidant Capacity in the Tassel of Collected Waxy Corn Germplasm " was revised according to the comments and suggestions of the reviewers.
The authors respond to the reviewers point by point.
The authors also check for possible errors, and the errors were revised and indicated by red letter.
Yours Sincerely,
Bhalang
Author Response File: Author Response.pdf
Reviewer 3 Report
In manuscript, Authors have presented fairly simple, but well-designed research on the differentiation of tassels from waxy corn genotypes in terms of the total content of phenolic compounds and anthocyanins, and antioxidant activity. Analytical and chemometric methods were properly selected. The results are shown in Tables and Figures in a clear manner. However, the manuscript is written chaotically in some parts and with using incorrect phrases. In my opinion, the quality of the text should be improved to make it more reader-friendly.
In title phrase “chemotypic analysis” is inadequate, because only TPC and TAC (not phenolic compound profile) were determined. Moreover “anthocyanins, phenolic compounds” is unclear. I suggest more specific title, e.g. “Variation in total phenolic, total anthocyanin contents, and antioxidant capacity of tassels from waxy corn genotypes”.
l. 21-22 and l. 77. Change “high-value anthocyanins, phenolic compounds and antioxidants” to “phenolic compounds with antioxidant activity”
l. 25, 28 and throughout the manuscript. It should be “DPPH•” or “DPPH radicals” (not together “DPPH• radicals”).
l. 30-31. Rather “Tassels of corn genotypes belonging to three of these clusters had high levels of phytochemicals along with antioxidant capacity.”
l. 51. Remove “valuable”
l. 52. Change “increase their value as co-products” to “have pro-health effects.”
l. 63. Change “functional diet products” to “functional food products”
l. 70. Change “medicinal food” to “functional food”
l. 125. Add “absorbance” before “measured”
l. 142-145. “activity of radical scavenging capacity” is incorrect. Change to “DPPH radical scavenging activity”. And next sentence: “The portion of 0.5 mL of sample extract 10x diluted in extraction solvent was mixed with 4.5 mL of 60 μM DPPH• solution in methanol.”
l. 148. “The Trolox equivalent antioxidant capacity (TEAC) was determined according method described by Re et al. [26]. The ABTS radical cation were obtained by mixing 7 mM of ABTS and 2.45 mM K2S2O8.”. Add publication of Re et al. (Free Rad Biol Med, 1999, 26, 1231–1237) to list of references. Again, use “ABTS radical cation” or “ABTS•+”
l. 175. Remove “important”
l. 177. Remove “radical scavenging data”
Footnote of Table 1. Remove “probability level”
Figure 1. The statistically significant differences are not marked above bars
l. 194-195. The same information is in l. 172-173.
l. 195-198. “Our results were in agreement…” – it is not clear which results the Authors have in mind. Please move this sentence immediately after discussing the mentioned results. Add “content” after “anthocyanin”
l. 198-200. Sentence is unclear. Please, rewrite.
l. 202-203. Remove this information. It is repeated in Conclusion section.
l. 223. “low TAC” - (?)
The fragment from lines 247-265 should be combined with the previous text (l. 214-242), because it contains repeated information. In addition, the Authors use non-definite statements for values (low/moderate/high), therefore the same value is sometimes referred to as low, and another time as moderate (e.g. l. 238 vs l. 264).
l. 252. “phenolic compounds with contamination of anthocyanins” –(?)
l. 269-271. Move to Conclusion section.
l. 290. “… total phenolic compounds and total anthocyanin contents, and antioxidant capacity…”
l. 293-295. Move to Conclusion section.
l. 297. Change “phytochemicals” to “total phenolic and total anthocyanin contents”. Add the name of analysed material.
Author Response
Dear Reviewer,
The manuscript entitled "Variability in Anthocyanins, Phenolic Compounds and Antioxidant Capacity in the Tassel of Collected Waxy Corn Germplasm " was revised according to the comments and suggestions of the reviewers.
The authors respond to the reviewers point by point.
The authors also check for possible errors, and the errors were revised and indicated by red letter.
Yours Sincerely,
Bhalang
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
1. This manuscript tried to classify their own accessions and succeed it. However, there is only slight benefit for readers because the origins of accessions are not disclosed. To make this paper more valuable, some discussions are expected. For example, is it possible to analyze the relationship between environmental factor (change of precipitation, temperature, solar irradiation, etc.)?
2. Usually we use principal component analysis in this kind of study if we have enough data. Calculating correlation coefficients after cluster analysis doesn’t look smart.
3. Introduction should focus into contents that are mentioned in the title toward the end. L40-L71 describes case studies and looks redundant. Authors studied about tassel, but cited articles used ears, grains, kernels, pollen and cobs. It causes confusing. Please focus into tassels simply. L72-L84 is considered as a main theme of this study. This part can be placed at the beginning of the introduction and case studies can be introduced among the description.
4. L175. An original article should be written objectively. Subjective words, such as “interestingly” should not be used.
5. L179. Inserted sentence can be placed after “respectively)” in L176. Method of introducing related articles in L176 looks too rough. Do they report G is the main factor?
6. L189. Authors studied tassels. Please explain the relationship between tassels and pollens.
7. L205. Inserted sentences mention general theories. Please analyze your data using these theories.
8. L209, L256, L257. “interesting” is a subjective word.
9. L217. “1.1”?
10. Figure 1. We don’t use alphabets to indicate difference when treatments are only two. Consider other expression.
11. Figure 2. Please consider the effective digit of the values.
12. L281. “1.1”?
Author Response
Dear Reviewer,
The manuscript entitled "Variability in Anthocyanins, Phenolic Compounds and Antioxidant Capacity in the Tassel of Collected Waxy Corn Germplasm" was revised in the second round according to the comments and suggestions of the reviewers.
The authors respond to the reviewers point by point.
The authors also check for possible errors, and the errors were revised and indicated by blue color.
Yours Sincerely,
Bhalang
Author Response File: Author Response.pdf
