Elemental Composition of Infusions of Herbs (Tisanes) of North Ossetia (the Caucasus)

Round 1

Reviewer 1 Report

The Scientific comment is described below.

Cultivated or obtained from wild, herbal raw materials may contain trace elements at various levels.

This study relates to the release of beneficial and toxic trace elements from herbal preparations during infusion.

The elemental contents of seven commercially available herbal tea products were dtermined prior to and and following two mode infusion. The total content of 57 elements.

These detailed chemical information are extremely important and are important data for the spread of herbs.

Author Response

Dear Reviewer 1,

Thank you for appreciation of our submission to Agriculture.

Reviewer 2 Report

The manuscript presents a very interesting topic concerning the assessment of the elemental composition of herbs. Herbs are a large group of plants distinguished by the fact that they contain active compounds that actively affect living organisms. The current trends in nutrition and the strongly promoted "ecological" lifestyle are more and more supported by consumers who consciously look for products of this type.

Currently, even in the most industrialized countries, there is an increase in interest in herbal medicine. It seems to have to do with the spread of the so-called civilization diseases, a decrease in natural resistance to infections and an increase in susceptibility to various types of allergies.

For these reasons, I consider the article very valuable.

However, I have a few minor comments (below):

Line 34: the authors cite 13 different references, I think this is too much, a few would suffice.Line 37: as above (citing as many as 15 sources)

Lines 62-70: The goal is unclearly formulated - the statement that the study is a continuation of previous research is too much of a simplification. I suggest that the authors describe the purpose of the research more precisely and also add a research hypothesis (which is missing in the article). 

Lines 73-89: It is not entirely clear how many samples of herbs were taken, what was their weight, how many samples were collected, when (in what year, month), were the herbs wild or cultivated? Complete this information.

Perhaps it is worth considering supplementing the article with a brief description of the ecological conditions of the studied area (description of weather conditions, soil type, etc.).  

I suggest the authors perform some statistical analysis, in order to test the significance of tested methods of brewing herbal tea on elemental composition of herbs and teas.

 The data in table 7 is repeated with the data in tables 3, 4 and 5. 

Lines 282-324: It seems that in the chapter "Results and discussion" the description of the biological significance of individual elements is unnecessary. Perhaps it would be better if only brief information about these elements was included. 

Author Response

Dear Reviewer 2,

Thank you for your valuable comments.

Line 34: the authors cite 13 different references, I think this is too much, a few would suffice. Line 37: as above (citing as many as 15 sources)

Answer:  We disagree with your point of view. This is just a small part of the papers that have been reviewed. Much more work could have been cited here.

Lines 62-70: The goal is unclearly formulated - the statement that the study is a continuation of previous research is too much of a simplification. I suggest that the authors describe the purpose of the research more precisely and also add a research hypothesis (which is missing in the article). 

Answer:  We have reformulated the purpose and hypothesis of the sudy.

Lines 73-89: It is not entirely clear how many samples of herbs were taken, what was their weight, how many samples were collected, when (in what year, month), were the herbs wild or cultivated? Complete this information.

Answer:  Information of wild or cultivated herbs was given initially, and we have added the rest in the existing Tables.

Perhaps it is worth considering supplementing the article with a brief description of the ecological conditions of the studied area (description of weather conditions, soil type, etc.).  

Answer: Done!

I suggest the authors perform some statistical analysis, in order to test the significance of tested methods of brewing herbal tea on elemental composition of herbs and teas.

Answer: Two non-parametric tests, applicable for small sample sizes and non-normal distributions, were applied. To verify whether the concentrations of elements in the aqueous solutions prepared using the 7 herbal mixtures are distinct, the data were grouped blend-wise and a Kruskal-Wallis test was performed. 

The data in table 7 is repeated with the data in tables 3, 4 and 5. 

Answer: Table 7 bears the features of a practical importance of our study, as it is dedicated to the essential elements namely, whereas Tables 3, 4 and 5 are of academic order.

Lines 282-324: It seems that in the chapter "Results and discussion" the description of the biological significance of individual elements is unnecessary. Perhaps it would be better if only brief information about these elements was included. 

Answer:  We still consider that the suggested description of individual elements is important, as not all readers are ware of them.

Reviewer 3 Report

The manuscript titled: “Elemental composition of infusions of herbs (tisanes) of North 2 Ossetia (the Caucasus)” contains interesting information about elemental composition of different herbal mixtures. The mineral composition is quite interesting, but I miss some more information such as differences in antioxidant capacity of the herbal mixtures. Those two aspects are the most remarkable properties of infusions and can constitute a more complete manuscript.

Some comments to the manuscript:

• Line 26: were or-der K, Ca, I think that or der must go out.
• Line 193-195, authors say: “The concentration of elements among the 7 herbal teas, with rare exceptions, 193 varies in the following range: K> Ca> P> S> Si> Mn> Al> Sr> Fe> Zn> Ba> Rb> Cu> Ti> 194 Mg> Ni> Mo> Cr> Co> Ce> V> La> W> Cs> As> Y> Cd> Nd> Ga> Pr> Sb> Be> Ge> Se> Zr> 195 Nb> Te> Sm> Eu> Gd> Tb> Dy> Ho> Er> Tm> Yb> Lu> Hf> Ta> Re> Tl> Bi> Th> U”. What do you mean when you say that varies in the following ranges? It is true that K is the element analyzed which presents the higher content, but it is also important to see the differences among herbs and there are other elements in which the differences among teas are bigger.
• I also miss the Na content. Didn’t you measure it?
• Values shown in table 3 are mean values of replicates of samples or they show a unique value obtained for a sample? It seems a unique value as you do not a show the error deviation. As herbs are not homogeneous samples must be analyzed in triplicate or more to have a mean value and standard deviation.
• Line 211-212: “Each herbal tea is characterized by its elemental composition. Depending on the 211 elemental composition, each herbal tea can be a source of various elements necessary for 212 the human body·.  That’s true but you must be sure that the differences are significative due to the variabilities that I have mention before.
• Lines 281-324 the information given her are not results. This could go in introduction sections.
• In this section is given some information that it was given before in results. You have to extract conclusions.

The concentrations of elements in 7 samples of herbal teas, with rare exceptions, 372 varies in the following range: K> Ca> P> S> Si> Mn> Al> Sr> Fe> Zn> Ba> Rb> Cu> Ti> 373 Mg> Ni> Mo> Cr> Co> Ce> V> La> W> Cs> As> Y> Cd> Nd> Ga> Pr> Sb> Be> Ge> Se> Zr> 374 Nb> Te> Sm> Eu> Gd> Tb> Dy> Ho> Er> Tm> Yb> Lu> Hf> Ta> Re> Tl> Bi> Th> U. 375

The percentage of extraction of K, Fe, Mo in most cases was not affected by the time 376 of infusion, whereas the extraction of Cu, Cr, Ca, Mg, Zn, Mn, P, Se in all or most of the 377 tisanes increased over time.

Author Response

Dear Reviewer 3,

Thank you for your comments.

• Line 26: were order K, Ca, I think that or der must go out.
• Line 193-195, authors say: “The concentration of elements among the 7 herbal teas, with rare exceptions,  varies in the following range: K> Ca> P> S> Si> Mn> Al> Sr> Fe> Zn> Ba> Rb> Cu> Ti> 194 Mg> Ni> Mo> Cr> Co> Ce> V> La> W> Cs> As> Y> Cd> Nd> Ga> Pr> Sb> Be> Ge> Se> Zr> 195 Nb> Te> Sm> Eu> Gd> Tb> Dy> Ho> Er> Tm> Yb> Lu> Hf> Ta> Re> Tl> Bi> Th> U”. What do you mean when you say that varies in the following ranges? It is true that K is the element analyzed which presents the higher content, but it is also important to see the differences among herbs and there are other elements in which the differences among teas are bigger.

Answer:  It is a traditional way of showing successive decrease of concentration  range of determined elements.

• I also miss the Na content. Didn’t you measure it?

Answer:  When brewing tea, we deliberately used bottled water ("Saint Spring") to provide an experiment close to the conditions for making an infusion. It is known that the extraction capacity of distilled water differs from that of spring water. However, the relatively high sodium content in the water used (12 mg / l, this is a blank sample = blank) did not allow its determination in extracts, where the content was approximately at the same level. The sodium content in dry teas has been determined. We have eliminated sodium from Table 3 to maintain consistency in dry samples and extracts.

• Values shown in table 3 are mean values of replicates of samples or they show a unique value obtained for a sample? It seems a unique value as you do not a show the error deviation. As herbs are not homogeneous samples must be analyzed in triplicate or more to have a mean value and standard deviation.

Answer:  As it was a plot study - to get an impression what comes to infusions, we use individual samples of each tea. A sentence about uncertainties of measurements is added. In the future working with other phyto-teas we shall subject triplicates of each sample to elemental analysis.

• Line 211-212: “Each herbal tea is characterized by its elemental composition. Depending on the elemental composition, each herbal tea can be a source of various elements necessary for  the human body·.  That’s true but you must be sure that the differences are significative due to the variabilities that I have mention before.

Answer:  Agree. We shall keep in mind possible variability in our future work.

• Lines 281-324 the information given her are not results. This could go in introduction sections.
• In this section is given some information that it was given before in results. You have to extract conclusions.

Answer:  Done.

The concentrations of elements in 7 samples of herbal teas, with rare exceptions, varies in the following range: K> Ca> P> S> Si> Mn> Al> Sr> Fe> Zn> Ba> Rb> Cu> Ti> 373 Mg> Ni> Mo> Cr> Co> Ce> V> La> W> Cs> As> Y> Cd> Nd> Ga> Pr> Sb> Be> Ge> Se> Zr> 374 Nb> Te> Sm> Eu> Gd> Tb> Dy> Ho> Er> Tm> Yb> Lu> Hf> Ta> Re> Tl> Bi> Th> U.

The percentage of extraction of K, Fe, Mo in most cases was not affected by the time  of infusion, whereas the extraction of Cu, Cr, Ca, Mg, Zn, Mn, P, Se in all or most of the  tisanes increased over time.

Answer:  What is the question?

Round 2

Reviewer 3 Report

Thank you for your comments.

• Line 26: were order K, Ca, I think that or der must go out.
• Line 193-195, authors say: “The concentration of elements among the 7 herbal teas, with rare exceptions, varies in the following range: K> Ca> P> S> Si> Mn> Al> Sr> Fe> Zn> Ba> Rb> Cu> Ti> 194 Mg> Ni> Mo> Cr> Co> Ce> V> La> W> Cs> As> Y> Cd> Nd> Ga> Pr> Sb> Be> Ge> Se> Zr> 195 Nb> Te> Sm> Eu> Gd> Tb> Dy> Ho> Er> Tm> Yb> Lu> Hf> Ta> Re> Tl> Bi> Th> U”. What do you mean when you say that varies in the following ranges? It is true that K is the element analyzed which presents the higher content, but it is also important to see the differences among herbs and there are other elements in which the differences among teas are bigger.

Well, Ok, if in agriculture terms you are familiar with that way of mention the order of the ions. But from an analytical point of view, it is better to comment for example in decreasing order of presence or something like that.

Answer: It is a traditional way of showing successive decrease of concentration range of determined elements.

• I also miss the Na content. Didn’t you measure it?

Answer: When brewing tea, we deliberately used bottled water ("Saint Spring") to provide an experiment close to the conditions for making an infusion. It is known that the extraction capacity of distilled water differs from that of spring water. However, the relatively high sodium content in the water used (12 mg / l, this is a blank sample = blank) did not allow its determination in extracts, where the content was approximately at the same level. The sodium content in dry teas has been determined. We have eliminated sodium from Table 3 to maintain consistency in dry samples and extracts.

Ok, it was not properly explained before but now I understand the process followed. Anyway, a spring water has other ions in its composition. The rest of the ions were not a problem? Did you assume that they were zero in the calculations?

• Values shown in table 3 are mean values of replicates of samples or they show a unique value obtained for a sample? It seems a unique value as you do not a show the error deviation. As herbs are not homogeneous samples must be analyzed in triplicate or more to have a mean value and standard deviation.

Answer: As it was a plot study - to get an impression what comes to infusions, we use individual samples of each tea. A sentence about uncertainties of measurements is added. In the future working with other phyto-teas we shall subject triplicates of each sample to elemental analysis.

I am sorry but I think that even for a plot study you must study reproducibility meanly when ICP.MS is employed sometimes differences are important. You can not ascertain that your results are true if no repetitions have been done.

• Line 211-212: “Each herbal tea is characterized by its elemental composition. Depending on the elemental composition, each herbal tea can be a source of various elements necessary for the human body·. That’s true but you must be sure that the differences are significative due to the variabilities that I have mention before.

Answer: Agree. We shall keep in mind possible variability in our future work.

I am sorry to say that, I understand that you have work a lot to get results but you must quantify the uncertainty of your data to have acceptable results to be published.

• Lines 281-324 the information given her are not results. This could go in introduction sections.
• In this section is given some information that it was given before in results. You have to extract conclusions.

Answer: Done.

The concentrations of elements in 7 samples of herbal teas, with rare exceptions, varies in the following range: K> Ca> P> S> Si> Mn> Al> Sr> Fe> Zn> Ba> Rb> Cu> Ti> 373 Mg> Ni> Mo> Cr> Co> Ce> V> La> W> Cs> As> Y> Cd> Nd> Ga> Pr> Sb> Be> Ge> Se> Zr> 374 Nb> Te> Sm> Eu> Gd> Tb> Dy> Ho> Er> Tm> Yb> Lu> Hf> Ta> Re> Tl> Bi> Th> U.

The percentage of extraction of K, Fe, Mo in most cases was not affected by the time of infusion, whereas the extraction of Cu, Cr, Ca, Mg, Zn, Mn, P, Se in all or most of the tisanes increased over time.

Answer: What is the question?

It was not a question I just wanted to point out that the same phrases have been used in results and conclusions sections.

I know that obtaining data for a manuscript and writing it is quite difficult and time cost but I think that without uncertainty of the data not too much things can be concluded all are conjecture.

Author Response

Dear Reviewer 3,

Thank you for your constructive criticism. Due to your remarks, we have considerably improved our paper! Our detailed answers are in the file attached (ANSWERS.docx)

Author Response File: Author Response.docx