Study of Antioxidant Activity of Garden Blackberries (Rubus fruticosus L.) Extracts Obtained with Different Extraction Solvents
, Georgiana Gabriela Codină 2, Melinda Héjja 3, Csaba Dezső András 1, Ancuța Chetrariu 2 and Adriana Dabija 2,*Round 1
Reviewer 1 Report
Dear Authors,
The results presented are important and should be published. However, my concerns are the following:
Lines 19-20: The authors should add in the text how the total phenolic, total anthocyanin and flavonoid content was measured.
Line 20: What detector the authors used for measuring by HPLC?
Line 38: have been “found” is missing at the end of the sentence.
Line 51: The authors should add what are the difficulties in the recovery of bioactive compounds from food industries by-products.
Lines 73-74: It is important to comment about the toxicity of other solvents used in the literature.
Line 78: The high temperature could additionally have an effect on degradation of phenolic compounds.
Line 79: “using different solvents for extraction” should be added.
Lines 82-83: The authors should explain in more detail how the blackberries were sampled.
Lines 124: The authors should add the reference to the method.
Line 181: The standards that were used should be added to the method. The calibration curve coefficients should be mention. The LOD and LOQ should be added.
Lines 184-188: Normal distribution of the variables should be tested.
Lines 190-206: The authors should explain in more detail how these findings are related to their results or omit the text.
Line 221 or line 244: The authors should explain why are the variabilities present. For example, total phenolic compounds present in blackberries could vary based on environmental and genetic factors.
In addition, the authors should explain what are the disadvantages of the method. Is determination of total phenolic compounds by Folin-Ciocalteu a very specific method?
Line 228: Is the “Excellent solvent for HPLC” related to excellent solvent for HPLC-DAD analysis?
Line 252: The authors should write down “HPLC-DAD method” not just “HPLC”. Why the authors did not use the HPLC-DAD method for determination of other compounds than gallic acid and quercetin?
Line 253: Do the authors mean differences instead of standard deviation? The authors should add additional data to the Figure 3. They should also explain why is important to study the standard deviations.
Line 327: The authors should try to explain why are significant differences present compared to the literature.
Line 330: The authors should explain clearly why theoretical study of the effect of acetonitrile water concentration on anthocyanin extraction based on Hansen solubility parameters is important for their research.
Overall, mine suggestion is that the manuscript would be acceptable with major revision. Substantial changes should be carried out before acceptance.
Good luck!
Author Response
Dear Reviewer,
We appreciate the time and effort that you dedicated to providing feedback on our manuscript “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”. and we are grateful for the insightful comments on and valuable improvements to our paper. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as following:
General comment:The results presented are important and should be published.
Response: Thank you!
Comment: Lines 19-20: The authors should add in the text how the total phenolic, total anthocyanin and flavonoid content was measured.
Response: Thanks for your kind reminders. We revised the sentence as follows: The total phenolic content (with Folin–Ciocâlteu reagent), total anthocyanin content (with pH differential method) and total flavonoid content (with aluminum chloride colorimetric method) were also measured. (Line 20-22)
Comment: Line 20: What detector the authors used for measuring by HPLC?
Response: We used DAD detector.We have now corrected in manuscript.
Comment: Line 38: have been “found” is missing at the end of the sentence.
Response: We have now corrected our typo error.
Comment: Line 51: The authors should add what are the difficulties in the recovery of bioactive compounds from food industries by-products.
Response: We have inserted the following sentence: The recovery of bioactive compounds from food industry by-products by extraction involves the co-extraction of non-phenolic substances such as sugars, organic acids and proteins, which requires subsequent purification processes.
Comment: Lines 73-74: It is important to comment about the toxicity of other solvents used in the literature.
Response: Thank you for your observation, we added the next sentence: Solvents with high polarity (ethanol and methanol) are favorable for use in the extraction of polar compounds such as phenolic compounds and flavonoids. Non-polar solvents, such as ether or solvents with low polarity such as chloroform, ester are used in specific cases, with a low frequency of use.
Comment: Line 78: The high temperature could additionally have an effect on degradation of phenolic compounds.
Response: Thank you for your observation, we have added the sentence.
Comment: Line 79: “using different solvents for extraction” should be added.
Response: Thank you for your observation, we have added the sentence.
Comment: Lines 82-83: The authors should explain in more detail how the blackberries were sampled.
Response: Thank you for your corrective comment, we have added the harvesting method.
Comment: Lines 124: The authors should add the reference to the method.
Response: We have added the reference.
Comment: Line 181: The standards that were used should be added to the method. The calibration curve coefficients should be mention. The LOD and LOQ should be added.
Response: We supplemented the method with the requested data.
Comment: Lines 184-188: Normal distribution of the variables should be tested.
Response: Thank you for your observation. Revised accordingly
Comment: Lines 190-206: The authors should explain in more detail how these findings are related to their results or omit the text.
Response: This section has been moved to the introduction.
Comment: Line 221 or line 244: The authors should explain why are the variabilities present. For example, total phenolic compounds present in blackberries could vary based on environmental and genetic factors.
Response: Total phenolic compounds present in blackberries could vary based on variety, climatic conditions of the year in question, soil fertility, harvest time or extraction method.
Comment: In addition, the authors should explain what are the disadvantages of the method. Is determination of total phenolic compounds by Folin-Ciocalteu a very specific method?
Response: Reducing sugars and ascorbic acid can be present in high amounts in plant food extracts,
and can reduce the effect of the Folin-Ciocalteu reagent, which distorts the TPC results.
Comment: Line 228: Is the “Excellent solvent for HPLC” related to excellent solvent for HPLC-DAD analysis?
Response: Thank you, we have corrected it.
Comment: Line 252: The authors should write down “HPLC-DAD method” not just “HPLC”. Why the authors did not use the HPLC-DAD method for determination of other compounds than gallic acid and quercetin?
Response: We agree with the reference point of view. We also intended to determine the amount of cyanidin-3-O -glycoside, but unfortunately the standard did not arrive by the time the analyses were performed.
Comment: Line 253: Do the authors mean differences instead of standard deviation? The authors should add additional data to the Figure 3. They should also explain why is important to study the standard deviations.
Response: We discussed the standars deviations, not the differences.
Comment: Line 327: The authors should try to explain why are significant differences present compared to the literature.
Response: Thank you for your suggestion, we have added to the manuscript the possible reasons that give differences between the results.
Comment: Line 330: The authors should explain clearly why theoretical study of the effect of acetonitrile water concentration on anthocyanin extraction based on Hansen solubility parameters is important for their research.
Response: We didn't think acetonitrile would be the best solvent. We were curious about what ratio of acetonitrile to water would be optimal for extraction, so we did some theoretical calculations. We plan to verify the theory in practice in the near future.
Comment: Overall, mine suggestion is that the manuscript would be acceptable with major revision. Substantial changes should be carried out before acceptance.
Response: We tried our best to improve the manuscript and made some changes in the manuscript. We appreciate for Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions!
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The work presented by Albert et al., “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”, characterizes the antioxidant properties of garden blackberries fruits grown in Romania. The authors reported the content of anthocyanins, flavonoids, total phenolics as well as the antiradical activities of blackberries fruits extracts obtained with different extraction solvents and the correlation between these parameters. The content of this manuscript has attracted a few questions and comments as listed below.
Besides difference in the source of the blackberries, almost identical works focusing on blackberries have already been previously and robustly investigated (please check Sellapan et al and Wang et el., references number 25 and 40, respectively). How is this work different from those similar works and what are the main contributions of the current study?
By the authors own admission, acidified ethanol is one of the most common solvents used in the extraction of bioactives from blackberries [lines 70, 95 and 190-192]. Is there any specific reason why the authors then decided to use 80 % ethanol (v/v) without any acidification? And seeing that all the other solvents were acidified and had better phenolic content and antioxidant activities, did the higher pH of the medium affect the effectiveness of ethanol as extractant? The authors should consider including acidified ethanol as one of the extractants and examining the phenolic and antioxidant attributes of the extract vis-à-vis the other solvents.
Lines 198-208: What is the relevance of this paragraph with respect to the stated aims of this work? The authors should consider removing it if it cannot be clarified.
Lines 321-327: Anthocyanins are obviously one of the main classes of phenolics in blackberries fruits and cyanidin-3-glucoside is the most abundant anthocyanin therein. The authors quantified quercetin (flavonoid) and gallic acid (phenolic acid) via HPLC analysis. The authors should also consider quantifying cyanidin-3-glucoside as representative anthocyanin.
The authors stated, “For gallic acid, our results were relatively close to the values obtained by Jacques et al. (2010), 350.49 mg/100 g fresh weight [42].’’ With your reported value being 88.25±0.478 mg/100 g fresh weight, the aforementioned statement is clearly inaccurate.
In several instances, the authors noted that their results were not in accord with previous reports in literature but included no justification for such. The authors should consider including plausible explanations in such cases.
The manuscript has a lot of grammatical errors. The authors should strongly consider getting help from a professional English language editing service provider.
Author Response
Dear Reviewer,
We appreciate the time and effort that you dedicated to providing feedback on our manuscript “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”. and we are grateful for the insightful comments on and valuable improvements to our paper. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as following:
Comment 1: The work presented by Albert et al., “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”, characterizes the antioxidant properties of garden blackberries fruits grown in Romania. The authors reported the content of anthocyanins, flavonoids, total phenolics as well as the antiradical activities of blackberries fruits extracts obtained with different extraction solvents and the correlation between these parameters. The content of this manuscript has attracted a few questions and comments as listed below.
Response: Thank you for carrefouly revised of our manuscript and for your comments.
Comment 2: Besides difference in the source of the blackberries, almost identical works focusing on blackberries have already been previously and robustly investigated (please check Sellapan et al and Wang et el., references number 25 and 40, respectively). How is this work different from those similar works and what are the main contributions of the current study?
Response: Wang et al. studied blueberries in which the main anthocyanin is malvidin -3-galactoside, in our study the main anthocyanin in blackberries is cyanidin -3-O-glucoside, and different extraction methods are required for each anthocyanin.
Comment 3: By the authors own admission, acidified ethanol is one of the most common solvents used in the extraction of bioactives from blackberries [lines 70, 95 and 190-192]. Is there any specific reason why the authors then decided to use 80 % ethanol (v/v) without any acidification? And seeing that all the other solvents were acidified and had better phenolic content and antioxidant activities, did the higher pH of the medium affect the effectiveness of ethanol as extractant? The authors should consider including acidified ethanol as one of the extractants and examining the phenolic and antioxidant attributes of the extract vis-à-vis the other solvents.
Response: We agree with the reviewer. We included in the discussion that this could be the reason for the lower value. Based on your suggestion, we intend to compare extraction with acidified and non-acidified ethanol to make sure we are wrong. Thank you for your helpful comment.
Comment 4: Lines 198-208: What is the relevance of this paragraph with respect to the stated aims of this work? The authors should consider removing it if it cannot be clarified.
Response: : Thank you for your observation. This section has been moved to the introduction
Comment 5: Lines 321-327: Anthocyanins are obviously one of the main classes of phenolics in blackberries fruits and cyanidin-3-glucoside is the most abundant anthocyanin therein. The authors quantified quercetin (flavonoid) and gallic acid (phenolic acid) via HPLC analysis. The authors should also consider quantifying cyanidin-3-glucoside as representative anthocyanin.
Response: We also intended to determine the amount of cyanidin-3-O -glycoside, but unfortunately the standard did not arrive by the time the analyses were performed.
Comment 6: The authors stated, “For gallic acid, our results were relatively close to the values obtained by Jacques et al. (2010), 350.49 mg/100 g fresh weight [42].’’ With your reported value being 88.25±0.478 mg/100 g fresh weight, the aforementioned statement is clearly inaccurate.
Response: The reviewer is right. This is our mistake, the value obtained by Jaques et al. for blackberries stored at -18C is 113.13 mg/100g fresh weight.
Comment 7: In several instances, the authors noted that their results were not in accord with previous reports in literature but included no justification for such. The authors should consider including plausible explanations in such cases.
Response: Thank you for your comment. We have added the following sentence: total phenolic compounds present in blackberries could vary based on variety, climatic conditions of the year in question, soil fertility, harvest time or extraction method.
Comment 8: The manuscript has a lot of grammatical errors. The authors should strongly consider getting help from a professional English language editing service provider.
Response: We went through the entire manuscript to eliminate grammatical mistakes.
Once again, thank you very much for your comments and suggestions!
Author Response File: Author Response.pdf
Reviewer 3 Report
This paper is focused on the characterization of the antioxidant properties of garden blackberries fruits cultivated in Romania. The manuscript is well written and I find it very easy to read. However, to be honest the whole structure is confusing since the authors declare that “the aim of research is to characterize the antioxidant properties of garden blackberries fruits grown in Romania” and conclude discussing which is the best solvent for the extraction of the interested analytes. In the manuscript the authors use a method for flavonoids which is affected by a huge bias and its data has no sense from my point of view, especially if compared to the others class of molecules. It’s also difficult to understand why blackberries cultivated in gardens in Romania, which are not produced by a specific or autoctonous sort, have to be characterized. I don’t find scientific novelty. The solvent mixture presented as the best between the combinations investigated (not the best at all) cannot be used by the industry so this data is of low relevance.
My main comments are listed below.
ABSTRACT
- Line 19: Do not declare how you measured quercitin and gallic acid if you don’t do the same for other compounds. On the opposite, you have to state it for all molecules you have mentioned in the abstract.
INTRODUCTION
- Line 38. You didn’t end the statement (have been..???).
- Figure 1: the figure quality is poor. Letters are not well defined.
MATERIAL AND METHODS
- Lines 82-83: Many data regarding the age of the plant, specie, terrain, rains, dimension, overall production, pesticides used and so on are missing. This is a very generic description and is not useful for a replication of the experiments.
- Lines 93-94: I think the authors are indicating several attempts of extracting conditions using published methods. Please, specify it.
- Line 98: I don’t understand the composition of this extracting phase. Please, indicate solvent (ACN) and HCl with its concentration like for the previous extracting phases.
- Section 2.2.: honestly, I don’t agree with the workflow used by the authors since there are too many variables that change per attempt. If you want to optimize your method you have to use design of experiments (DOE). I don’t agree also to the use of 4 combinations of solvent, acid and concentration. In this way it seems that you are working by trial and error.
- Line 99: I invite the authors to replace “to better cell wall rupture” with “for a better cell wall rupture”. Sounds better.
- Line 109: How much time does it take?
- Line 177: the mobile phase is a binary solvent mixture since formic acid is not a solvent. Modify this statement.
- Section 2.8.: The authors also don’t explain why they decided to determine the concentrations of gallic acid and quercetin.
RESULTS AND DISCUSSION
- Lines 190 – 210: these are not results so it’s better to move them into the introduction and cite them in the discussion of results.
- Figure 2: the figure quality is poor and chemical structures are not well defined, please upgrade it.
- Line 221: reporting the average values could be a useful for the readers.
- Lines 248 – 252: summarizing, the authors are declaring that the data on the total amount of flavonoids in the manuscript is not reliable. In this case, it cannot be published. In addition, since Celant have previously detected this issue, my expectation is to not find it in a new manuscript. I invite the authors to measure the total amount of flavonoids with another method (maybe HPLC, as was indicated).
- Line 282: “may” has no sense in the sentence.
- Line 305: Remove the year (201) in brackets.
CONCLUSIONS
- Conclusions explain what is the best solvent mixture for the extraction of blackberries and the role of Hansen parameters in the extraction mixture. There is no citation regarding the obtained results and there is no connection with the aim of the manuscript which is a characterization; here I find only the evaluation of solvents which are also unsuitable for the industrial production.
- The authors state that they want to promote blackberries cultivated in Romania as a premium functional food; however, no correlation with recommended values of investigated analytes was done.
In the end my opinion on this manuscript is negative and I invite the authors to reconsider the whole structure, what are they interested to find and to demonstrate, and if all of these data are supported enough. In this form I am sorry to say that from my point of view this article has to be rejected.
Author Response
Dear Reviewer,
We appreciate the time and effort that you dedicated to providing feedback on our manuscript “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”. and we are grateful for the insightful comments on and valuable improvements to our paper. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as following:
This paper is focused on the characterization of the antioxidant properties of garden blackberries fruits cultivated in Romania. The manuscript is well written and I find it very easy to read. However, to be honest the whole structure is confusing since the authors declare that “the aim of research is to characterize the antioxidant properties of garden blackberries fruits grown in Romania” and conclude discussing which is the best solvent for the extraction of the interested analytes. In the manuscript the authors use a method for flavonoids which is affected by a huge bias and its data has no sense from my point of view, especially if compared to the others class of molecules. It’s also difficult to understand why blackberries cultivated in gardens in Romania, which are not produced by a specific or autoctonous sort, have to be characterized. I don’t find scientific novelty. The solvent mixture presented as the best between the combinations investigated (not the best at all) cannot be used by the industry so this data is of low relevance.
My main comments are listed below.
ABSTRACT
Comment:Line 19: Do not declare how you measured quercitin and gallic acid if you don’t do the same for other compounds. On the opposite, you have to state it for all molecules you have mentioned in the abstract.
Response: Thank you. This was revised according to the comment.
INTRODUCTION
Comment: Line 38. You didn’t end the statement (have been..???).
Response: We have now corrected our typo error: have been found.
Comment: Figure 1: the figure quality is poor. Letters are not well defined.
Response: Thank you, the figure was improved.
MATERIAL AND METHODS
Comment: Lines 82-83: Many data regarding the age of the plant, specie, terrain, rains, dimension, overall production, pesticides and so on are missing. This is a very generic description and is not useful for a replication of the experiments.
Response: We don't cultivated the plant, we purcheased them and the conditions of cultivation of the plant of origin were not monitored. This manuscript did not propose an agronomic study of the crop plant.
Comment: Lines 93-94: I think the authors are indicating several attempts of extracting conditions using published methods. Please, specify it.
Response: For the determination of the antioxidant capacity of blackcurrant, 4 extraction methods reported in the literature were chosen. We did not choose just one in order to obtain a better characterization of the fruit.
Comment: Line 98: I don’t understand the composition of this extracting phase. Please, indicate solvent (ACN) and HCl with its concentration like for the previous extracting phases.
Response: Revised accordingly.
Comment: Section 2.2.: honestly, I don’t agree with the workflow used by the authors since there are too many variables that change per attempt. If you want to optimize your method you have to use design of experiments (DOE). I don’t agree also to the use of 4 combinations of solvent, acid and concentration. In this way it seems that you are working by trial and error.
Response: Thank you for your suggestions, we will take into account these pertinent observations in the future, but we are not familiar with this statistical program. We consider that a combination as complex as possible, as in our study, with as many input variables as possible leads to an adequate response. We mention that all variables are important in the study.
Comment:Line 99: I invite the authors to replace “to better cell wall rupture” with “for a better cell wall rupture”. Sounds better.
Response: Thank you. We have replaced.
Comment:Line 109: How much time does it take?
Response: It takes 9 hours.
Comment:Line 177: the mobile phase is a binary solvent mixture since formic acid is not a solvent. Modify this statement.
Response: Thank you. We have replaced.
Comment:Section 2.8.: The authors also don’t explain why they decided to determine the concentrations of gallic acid and quercetin.
Response: The calibration curves were determined using gallic acid for the total content of polyphenols and quercitin respectively for the flavonoid content. From the specialized literature consulted it appears that most often the total content of polyphenols and flavonoids is expressed with the help of gallic acid, respectively of quercitin.
RESULTS AND DISCUSSION
Comment: Lines 190 – 210: these are not results so it’s better to move them into the introduction and cite them in the discussion of results.
Response: This section has been moved to the introduction
Comment: Figure 2: the figure quality is poor and chemical structures are not well defined, please upgrade it.
Response: Thank you, the figure was improved
Comment: Line 221: reporting the average values could be a useful for the readers.
Response: Thank you, we added the average values.
Comment: Lines 248 – 252: summarizing, the authors are declaring that the data on the total amount of flavonoids in the manuscript is not reliable. In this case, it cannot be published. In addition, since Celant have previously detected this issue, my expectation is to not find it in a new manuscript. I invite the authors to measure the total amount of flavonoids with another method (maybe HPLC, as was indicated).
Response: Thank you for your suggestions, unfortunately we no longer have the sets of samples, we consider that your observations are pertinent and we will take these into account in future research.
Comment: Line 282: “may” has no sense in the sentence.
Response: Thank you. We have removed.
Comment: Line 305: Remove the year (201) in brackets.
Response: Thank you. We have removed.
CONCLUSIONS
Comment: Conclusions explain what is the best solvent mixture for the extraction of blackberries and the role of Hansen parameters in the extraction mixture. There is no citation regarding the obtained results and there is no connection with the aim of the manuscript which is a characterization; here I find only the evaluation of solvents which are also unsuitable for the industrial production. The authors state that they want to promote blackberries cultivated in Romania as a premium functional food; however, no correlation with recommended values of investigated analytes was done.
Response: Thank you. This was revised according to the comment.
Once again, thank you very much for your comments and suggestions!
Author Response File: Author Response.pdf
Reviewer 4 Report
An interesting paper on the antioxidant activity of garden blackberries extracts, while using different solvents. Can be of interest for the readers of the journal. Well description of the current state of the art in the Introduction. Methodology ok. Maybe a few more details on how the experimenters grew their own material? Would have been better to be collected? Please explain the (possible ) differences in Discussion section. Comparison with other studies is other wise well done. Conclusions are balanced and ok.
Author Response
Dear Reviewer,
We appreciate the time and effort that you dedicated to providing feedback on our manuscript “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”. and we are grateful for the insightful comments on and valuable improvements to our paper. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as following:
Comment: An interesting paper on the antioxidant activity of garden blackberries extracts, while using different solvents. Can be of interest for the readers of the journal. Well description of the current state of the art in the Introduction. Methodology ok. Maybe a few more details on how the experimenters grew their own material? Would have been better to be collected? Please explain the (possible ) differences in Discussion section. Comparison with other studies is other wise well done. Conclusions are balanced and ok.
Response: Thank you for your review and comments on our manuscript. We have added the harvesting method: The blackberry fruits were hand-harvested at full maturity from randomly selected plants, the fruits without any damage were selected and stored at -20°C until the analysis. The differences can be explained by the fact that the antioxidant capacity in blackberries could vary based on variety, climatic conditions of the year in question, soil fertility, harvest time or extraction method.
Once again, thank you very much for your comments and suggestions!
Author Response File: Author Response.pdf
Reviewer 5 Report
In my opinion, the article titled: "Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents" could be very interesting for Applied sciences readers, but it needs some small improvements, listed below:
Lines 14 – 15 – "Berries are known to be rich in antioxidants, given by their high polyphenols and vitamins content, possessing high disease prevention potential." – Please, note that in the botanical sense the word berries has a broader meaning so I would recommend that you use the word blackberries. Also, please consider to change the term "given by" to "thanks to" or "due to" (because using the term "given by" the sentence seems incomplete).
Lines 37 – 38 – "Among the most important bioactive compounds in blackberries flavonoids, phenolic acids, tannins, anthocyanins, and vitamins have been [4,5]." – Please, rephrase the sentence.
Lines 46 – 47 – "The recovery of them by variate (conventional and innovative) extraction processes are profitably applied in various industrially". – Please, rephrase the sentence.
Line 54 – "…compote, unfermented and fermented beverages, but are may replace synthetic additive…" – Please, rephrase.
Lines 55 – 57 – "Also, the use of blackberries improves the nutritional value and shelf life of finished foodstuffs, as can be seen in Figure 1 [13-15]." – Please, rephrase the sentence. Complete the text related to Figure 1. Do not just write "as can be seen in Figure 1".
Lines 75 – 76 – "Different extraction temperatures may have affected the types of polyphenols extracted." – Please, note that this sentence should be in the present tense, not in the past tense, for the sake of understanding the text.
Line 83 – "…and stored at -20 ̊ C until use." --> "-20 °C"
Line 125 – 128 – "The antioxidant potential of blackcurrant bud and leaf extracts was also determined using a FRAP assay measuring the change in absorbance at λ=593 nm due to the formation of a blue-colored Fe2+-tripyridyl-triazine compound from colorless oxidized Fe3+-form by the action of electron-donating antioxidants [26]." – Please, correct the data. This is a mistake in the text because in the materials and under the preparation of samples (lines 81 – 106) you do not mention buds and leaves but only frozen garden blackberries.
Line 130 – "…16 mL acetic acid + 1 L distilled water; TPTZ solution: 0.312 g TPTZ + 100 mL distilled water + 336 μL HCl; Ferric chloride solution: 0.54 g FeCl3 + 100 mL distilled water." – Please, note that here you use capital letter L for liter, and through the previous text you used lowercase letter; please use the same one throughout the whole text.
Line 348 – "…summarized in Table 2." – Please, note that here you are referring to the wrong table. --> "…summarized in Table 5."
Lines 430 – 433 – "With our results, we would like to emphasize the nutritional role of blackberries and the data obtained suggest that the blackberries growing and harvested in our region are suitable for the production of premium functional foods. Future studies are required to continue the use of these valuable blackberries in medicinal foods for various diseases." – Please, rephrase the sentences. Better explain what you wanted to point out.
In my opinion, the language, grammar and syntax of the article "Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents" should be checked.
Author Response
Dear Reviewer,
We appreciate the time and effort that you dedicated to providing feedback on our manuscript “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”. and we are grateful for the insightful comments on and valuable improvements to our paper. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as following:
Comment: In my opinion, the article titled: "Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents" could be very interesting for Applied sciences readers, but it needs some small improvements, listed below:
Response: Thank you for suggestion
Comment: Lines 14 – 15 – "Berries are known to be rich in antioxidants, given by their high polyphenols and vitamins content, possessing high disease prevention potential." – Please, note that in the botanical sense the word berries has a broader meaning so I would recommend that you use the word blackberries. Also, please consider to change the term "given by" to "thanks to" or "due to" (because using the term "given by" the sentence seems incomplete).
Response: Thank you for suggestion We revised this sentence as follows: Blackberries are known to be rich in antioxidants, due to their high polyphenols and vitamins content, possessing high disease prevention potential.
Comment: Lines 37 – 38 – "Among the most important bioactive compounds in blackberries flavonoids, phenolic acids, tannins, anthocyanins, and vitamins have been [4,5]." – Please, rephrase the sentence.
Response: We have now corrected our typo error: have been found.
Comment: Lines 46 – 47 – "The recovery of them by variate (conventional and innovative) extraction processes are profitably applied in various industrially". – Please, rephrase the sentence.
Response: Thank you very much for nice reminder. We revised this sentence as follows: The recovery of them by variate (conventional and innovative) extraction processes are profitably applied in various industrial purposes.
Comment:Line 54 – "…compote, unfermented and fermented beverages, but are may replace synthetic additive…" – Please, rephrase.
Response: Thank you for suggestion We revised this sentence as follows Different extraction temperatures can affect the types of polyphenols extracted.
Comment: Lines 55 – 57 – "Also, the use of blackberries improves the nutritional value and shelf life of finished foodstuffs, as can be seen in Figure 1 [13-15]." – Please, rephrase the sentence. Complete the text related to Figure 1. Do not just write "as can be seen in Figure 1".
Response: Thank you! Revised accordingly.
Comment:Lines 75 – 76 – "Different extraction temperatures may have affected the types of polyphenols extracted." – Please, note that this sentence should be in the present tense, not in the past tense, for the sake of understanding the text.
Response: Thank you very much for nice reminder. We revised this sentence as follows: Different extraction temperatures may affect the types of polyphenols extracted.
Comment:Line 83 – "…and stored at -20 ̊ C until use." --> "-20 °C"
Response: Revised accordingly.
Comment:Line 125 – 128 – "The antioxidant potential of blackcurrant bud and leaf extracts was also determined using a FRAP assay measuring the change in absorbance at λ=593 nm due to the formation of a blue-colored Fe2+-tripyridyl-triazine compound from colorless oxidized Fe3+-form by the action of electron-donating antioxidants [26]." – Please, correct the data. This is a mistake in the text because in the materials and under the preparation of samples (lines 81 – 106) you do not mention buds and leaves but only frozen garden blackberries.
Response: Thank you, we have corrected.
Comment:Line 130 – "…16 mL acetic acid + 1 L distilled water; TPTZ solution: 0.312 g TPTZ + 100 mL distilled water + 336 μL HCl; Ferric chloride solution: 0.54 g FeCl3 + 100 mL distilled water." – Please, note that here you use capital letter L for liter, and through the previous text you used lowercase letter; please use the same one throughout the whole text.
Response: Revised accordingly.
Comment:Line 348 – "…summarized in Table 2." – Please, note that here you are referring to the wrong table. --> "…summarized in Table 5."
Response: Revised accordingly.
Comment: Lines 430 – 433 – "With our results, we would like to emphasize the nutritional role of blackberries and the data obtained suggest that the blackberries growing and harvested in our region are suitable for the production of premium functional foods. Future studies are required to continue the use of these valuable blackberries in medicinal foods for various diseases." – Please, rephrase the sentences. Better explain what you wanted to point out.
Response: Thank you for suggestion We revised this sentence as follows: With our results, we would like to emphasize the nutritional role of blackberries, the obtained data suggest that the blackberries growing and harvested in our region are suitable for the production of premium functional foods. With modern and efficient extraction methods can be produced pure blackberry anthocyanin extracts. Agricultural and food processing wastes from the blackberry industry are potential sources of anthocyanins. Blackberry has been used as a beneficial food and food ingredient and can contribute even more through modern extraction methods.
Comment: In my opinion, the language, grammar and syntax of the article "Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents" should be checked.
Response: : We went through the entire manuscript to eliminate grammatical mistakes.
Once again, thank you very much for your comments and suggestions!
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear Authors,
even though, substantial changes were made, my concerns are still the following:
Line 52: The authors should additionally add what are the difficulties in the recovery of bioactive such as phenolic compounds from food industries by-products. Is there a problem with the stability and oxidation of these compounds? Are these extraction techniques economical viable?
Lines 110-113: The authors should add the location of collection of the fruit and soil type.
Line 115: Standards should be added to the section 2.1 (Chemicals).
Lines 220-221: The authors should comment on normal distribution of the variables. Were the variables normal distributed? What was the number of the samples?
In addition, the authors should explain in the text what are the disadvantages of the method. Is determination of total phenolic compounds by Folin-Ciocalteu a very specific method?
Line 275: The authors should add additional data to the y axis of the graph. Is it standard deviation? They should also explain in the text why is important to study the standard deviations.
The authors should explain in the text why are significant differences present compared to the literature.
The authors should explain clearly in the text why theoretical study of the effect of acetonitrile water concentration on anthocyanin extraction based on Hansen solubility parameters is important for their research.
Good Luck!
Author Response
10 April 2022
Dear Referee,
We would like to thank the referee for the close reading and for the proper suggestions. We hope that we provide all the answers to the reviewer’s comments.
Thank you very much for the recommendations to publish our paper entitled “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”.
The present version of the paper has been revised according to the reviewer’s suggestions.
We uploaded the corrected version of the article for which we used the red colour for the addition text.
REFERE COMMENTS:
Reviewer: Line 52: The authors should additionally add what are the difficulties in the recovery of bioactive such as phenolic compounds from food industries by-products. Is there a problem with the stability and oxidation of these compounds? Are these extraction techniques economical viable?
Response: We want to thank to the referee for the close reading of our manuscript. We completed the manuscript with more information related to the referee questions according to his/her suggestions.
Reviewer: Lines 110-113: The authors should add the location of collection of the fruit and soil type.
Response: Thank you. We have completed the manuscript with the requested information.
Reviewer: Line 115: Standards should be added to the section 2.1 (Chemicals).
Response: We want to thank to the referee for his/her observation. We added in the manuscript according to the referee suggestions.
Reviewer: Lines 220-221: The authors should comment on normal distribution of the variables. Were the variables normal distributed? What was the number of the samples?
Response: The normality test was performed on three variables from three independent measurements. We completed more information in the manuscript according to the referee suggestions.
Reviewer: In addition, the authors should explain in the text what the disadvantages of the method are. Is determination of total phenolic compounds by Folin-Ciocalteu a very specific method?
Response: We completed with more information related to the disadvantges of the method and about specificity of the Folin-Ciocalteu method.
Reviewer: Line 275: The authors should add additional data to the y axis of the graph. Is it standard deviation? They should also explain in the text why is important to study the standard deviations.
Response: Thank you, we have corrected it.
Reviewer: The authors should explain in the text why are significant differences present compared to the literature.
Response: We tried to complete with explications the discussion parts according to the referee suggestions.
Reviewer: The authors should explain clearly in the text why theoretical study of the effect of acetonitrile water concentration on anthocyanin extraction based on Hansen solubility parameters is important for their research.
Response: We want to thank to the referee for his/her observation. We completed in the manuscript according to the referee suggestions.
Reviewer: Good Luck!
Response: We tried our best to improve the manuscript and made changes in the manuscript. We appreciate for Reviewers’ warm work earnestly and hope that the correction will meet with approval. Once again, thank you very much for your comments and suggestions
Sincerely,
Dabija et co.
Author Response File: Author Response.pdf
Reviewer 2 Report
Albert et., thanks for the revision. This manuscript still has a few concerns worthy of your attention. Please find below.
The conclusions are disconnected from the main aims of the work, i.e., evaluation of antioxidant properties of garden blackberries fruits grown in Romania. The authors had rather focused their conclusions on the different extraction solvents and nutritional relevance of the blackberries. The authors are strongly encouraged to improve the conclusion by focusing on the stated aims and the obtained results as it pertains to those aims. Of course, authors can provide their perspectives on the implications and general relevance of their findings.
Thanks.
Author Response
10 April 2022
Dear Referee,
We would like to thank the referee for the close reading and for the proper suggestions. We hope that we provide all the answers to the reviewer’s comments.
Thank you very much for the recommendations to publish our paper entitled “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”.
The present version of the paper has been revised according to the reviewer’s suggestions.
We uploaded the corrected version of the article for which we used the red colour for the addition text.
REFERE COMMENTS:
Albert et al,, thanks for the revision. This manuscript still has a few concerns worthy of your attention. Please find below.
The conclusions are disconnected from the main aims of the work, i.e., evaluation of antioxidant properties of garden blackberries fruits grown in Romania. The authors had rather focused their conclusions on the different extraction solvents and nutritional relevance of the blackberries. The authors are strongly encouraged to improve the conclusion by focusing on the stated aims and the obtained results as it pertains to those aims. Of course, authors can provide their perspectives on the implications and general relevance of their findings.
Response: We want to thank to the referee for the close reading of our manuscript. We tried our best to improve the manuscript and made changes in the manuscript. We appreciate for Reviewers’ warm work earnestly and hope that the correction will meet with approval. Once again, thank you very much for your comments and suggestions.
Sincerely,
Dabija et co.
Author Response File: Author Response.pdf
Reviewer 3 Report
The authors thoroughly revised the manuscript, bringing it a significant improvement in terms of clarity, presentation quality and readability. I have found some typos that I urge the authors to correct.
- Lines 14-15: replace "possessing" with some other forms to make it sound better. Remove "-" between good and quality.
- Line 16: The aim of "this" research..
- Figure 2 caption: replace "glucoZide" with "glucoSide"
Despite this huge work, the main lacks of this paper which I have previously underlined are still present. Because of that, to allow this paper to be published I ask the authors to rewrite abstract, part of the introduction, and conclusion in order to give it a better linearity. In fact, abstract and introduction still state that the aim of this research is to characterize blackberries even though the conclusion doesn't comment this results but are only focused on solvents and extraction optimization. The authors are invited to be more coherent in all sections of the paper. From my point of view it could be good to rewrite conclusions discussing results first and then what was discovered about the extraction method. If the title is: "Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents" conclusions cannot start with a focus on extraction method.
These conceptual improvements are crucial for publication.
Author Response
10 April 2022
Dear Referee,
We would like to thank the referee for the close reading and for the proper suggestions. We hope that we provide all the answers to the reviewer’s comments.
Thank you very much for the recommendations to publish our paper entitled “Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents”.
The present version of the paper has been revised according to the reviewer’s suggestions.
We uploaded the corrected version of the article for which we used the red colour for the addition text.
REFERE COMMENTS:
Responds to the reviewer’s comments:
The authors thoroughly revised the manuscript, bringing it a significant improvement in terms of clarity, presentation quality and readability. I have found some typos that I urge the authors to correct.
Response: We want to thank to the referee for the close reading of our manuscript.
Referee: Lines 14-15: replace "possessing" with some other forms to make it sound better. Remove "-" between good and quality.
Response: We have now corrected our typo error.
Reviewer: Line 16: The aim of "this" research.
Response: We revised.
Reviewer: Figure 2 caption: replace "glucozide" with "glucoside".
Response: We revised.
Reviewer: Despite this huge work, the main lacks of this paper which I have previously underlined are still present. Because of that, to allow this paper to be published I ask the authors to rewrite abstract, part of the introduction, and conclusion in order to give it a better linearity. In fact, abstract and introduction still state that the aim of this research is to characterize blackberries even though the conclusion doesn't comment these results but are only focused on solvents and extraction optimization. The authors are invited to be more coherent in all sections of the paper. From my point of view it could be good to rewrite conclusions discussing results first and then what was discovered about the extraction method. If the title is: "Study of antioxidant activity of garden blackberries (Rubus fruticosus L.) extracts obtained with different extraction solvents" conclusions cannot start with a focus on extraction method.
These conceptual improvements are crucial for publication.
Response: We tried our best to improve the manuscript and made changes in the manuscript. We appreciate for Reviewers’ warm work earnestly and we hope that the correction made by us in the manuscript will meet with your approval. Once again, thank you very much for your comments and suggestions.
Sincerely,
Dabija et co.
Author Response File: Author Response.pdf
