Hg Content in EU and Non-EU Processed Meat and Fish Foods

Round 1

Reviewer 1 Report

The article "Hg Content in UE and not UE Processed Foods" shows the determination of Hg in different processed food products (beef, pork, poultry, seafood) using a direct mercury analyser (DMA-80). A total of 72 processed samples, 30 of canned meat (beef, pork, chicken), 32 of canned or dried fish (tuna, mackerel, sardines, salmon) and 10 of seafood (salmon) and 10 of natural or dried seafood (shrimps and crabs) have been analysed to study the possible risks derived from an excessive consumption of these products according to EFSA guidelines. For this purpose, total tolerable weekly intake values for Hg have been calculated for each species analysed. However, the manuscript lacks a more critical discussion of the results obtained, comparing with results obtained in other previously published works. The manuscript needs to be improved before it is accepted for possible publication.

Authors must consider the following indications for improving the manuscript:

-       The wording of the whole manuscript should be revised, especially in the introduction where many unconnected paragraphs appear.

-       The introduction should be expanded by including results from relevant publications that help to show sufficient background on the topic.

-       The methodology applied for hg analysis should be explained in a more detailed and orderly manner.

-       The section 2.4 Method validation should only show the criteria followed for the validation of the method, without including the validation results obtained. These results should be transferred to a point included in the section 3. Results.

-       The results shown in table 2 and figure 1 should be discussed in more detail, comparing with results obtained in previously published work.

-       The equation used for the calculation of the % TWI should be shown in the manuscript.

 

-       Conclusions are too poor and should be extended and improved.

 

Author Response

The article "Hg Content in UE and not UE Processed Foods" shows the determination of Hg in different processed food products (beef, pork, poultry, seafood) using a direct mercury analyser (DMA-80). A total of 72 processed samples, 30 of canned meat (beef, pork, chicken), 32 of canned or dried fish (tuna, mackerel, sardines, salmon) and 10 of seafood (salmon) and 10 of natural or dried seafood (shrimps and crabs) have been analysed to study the possible risks derived from an excessive consumption of these products according to EFSA guidelines. For this purpose, total tolerable weekly intake values for Hg have been calculated for each species analysed. However, the manuscript lacks a more critical discussion of the results obtained, comparing with results obtained in other previously published works. The manuscript needs to be improved before it is accepted for possible publication.

Authors must consider the following indications for improving the manuscript:

-       The wording of the whole manuscript should be revised, especially in the introduction where many unconnected paragraphs appear.

Authors: Whole manuscript has been revised.

 

-       The introduction should be expanded by including results from relevant publications that help to show sufficient background on the topic.

Authors: The introduction has been expanded.

 

-       The methodology applied for hg analysis should be explained in a more detailed and orderly manner.

Authors: Corrections have been made.

 

-       The section 2.4 Method validation should only show the criteria followed for the validation of the method, without including the validation results obtained. These results should be transferred to a point included in the section 3. Results.

Authors:  The results obtained for the method validation were reported in section 3.1.

 

-       The results shown in table 2 and figure 1 should be discussed in more detail, comparing with results obtained in previously published work.

Authors: The results have been discussed in more detail.

 

-       The equation used for the calculation of the % TWI should be shown in the manuscript.

Authors: The equation used to calculate the TWI % was added in the manuscript.

 

-       Conclusions are too poor and should be extended and improved.

Authors: Conclusions have been extended and improved.

Reviewer 2 Report

This work employed a direct Hg analyzer to monitor Hg contents in UE and not UE processed meat and fish food and then performed a dietary exposure assessment of Hg for Messina consumers. However, I cannot find enough novelty and significance for this work. So, I think this work cannot be accepted in this current form. And the detailed comments are listed as follows:

1. Paper title: “processed foods” should be revised to “processed meat and fish foods”; the monitoring place “Messina in Italy” should be addressed here.

2. The logicality of the introduction section is in a mess, and I cannot grasp the theme. I think Hg contamination, processed meat and fish foods, and risk assessment of Hg exposure should be the focuses.

3. Line 78-83: the methods of Hg analysis should be listed and compared. Direct sampling Hg analysis based on ETV, catalytic pyrolysis, and amalgamation is only one of these methods. Furthermore, DMA-80 is a commercialized serial number rather a analytical technique.

4. Line 124: spectrophotometry should be spectrometry.

5. Line 139: sensibility should be sensitivity.

6. Line 142: when the equations of 3.3 σ/b and 10 σ/b were used, n must be set as 10 or 11 rather than n=6 according to IUPAC. Based on my experience of using DMA80, the method LOD of Hg for 0.1 sample size should be lower than 1 μg/kg.

7. The conclusion about correlation between fat and mercury content in this work is lack of evidence considering the source diversity of raw materials for processed fish foods, eg. olive oil vs. lipid in fish. This study on correlation should be performed based on limited experimental conditions.

8. The dietary exposure of Hg via meat and fish foods is too simple. And age, gender, and food habits are out of consideration in this wok.

9. The discussion is so simple that I cannot find any novelty and significance compared with the previous studies.

Author Response

Comments and Suggestions for Authors:

 

This work employed a direct Hg analyzer to monitor Hg contents in UE and not UE processed meat and fish food and then performed a dietary exposure assessment of Hg for Messina consumers. However, I cannot find enough novelty and significance for this work. So, I think this work cannot be accepted in this current form. And the detailed comments are listed as follows:

 

1. Paper title: “processed foods” should be revised to “processed meat and fish foods”; the monitoring place “Messina in Italy” should be addressed here.

Authors: The paper title has been changed.

 

 

2. The logicality of the introduction section is in a mess, and I cannot grasp the theme. I think Hg contamination, processed meat and fish foods, and risk assessment of Hg exposure should be the focuses.

Authors: Corrections have been made.

 

 

3. Line 78-83: the methods of Hg analysis should be listed and compared. Direct sampling Hg analysis based on ETV, catalytic pyrolysis, and amalgamation is only one of these methods. Furthermore, DMA-80 is a commercialized serial number rather a analytical technique.

Authors: Corrections have been made.

 

 

4. Line 124: spectrophotometry should be spectrometry.

Authors: Given that we are working at the typical wavelength of mercury, it is correct to use the term atomic absorption spectrophotometry. However, for greater precision, it was decided to replace this term with atomic absorption spectroscopy.

 

 

5. Line 139: sensibility should be sensitivity.

Authors: Corrections have been made.

 

 

6. Line 142: when the equations of 3.3 σ/b and 10 σ/b were used, n must be set as 10 or 11 rather than n=6 according to IUPAC. Based on my experience of using DMA80, the method LOD of Hg for 0.1 sample size should be lower than 1 μg/kg.

Authors: Changes on the value of n have been made. Relative to the LOD value for mercury, it is true that the DMA-80 analysis can reach a lower limit of 1 μg/kg. However, our research group, initially conducted a literature search to observe the mercury ranges found in other studies on the following type of products. In this regard, from our experimental evidence, it is possible to conclude how the LOD value we obtained is more than sufficient for the purpose of analysis.

 

7. The conclusion about correlation between fat and mercury content in this work is lack of evidence considering the source diversity of raw materials for processed fish foods, eg. olive oil vs. lipid in fish. This study on correlation should be performed based on limited experimental conditions.

Authors: No such correlation between mercury and fat content has been found in the literature. In fact, as indicated in the text, in some studies the trend appears to be opposite. However, subsequent studies will focus on obtaining more data to confirm this hypothesis.

 

8. The dietary exposure of Hg via meat and fish foods is too simple. And age, gender, and food habits are out of consideration in this wok.

Authors: Regarding age and sex, as already specified in the text, it was decided to consider a body weight of 70 Kg for an adult as a reference for the calculation of Hg dietary exposure.  In addition, Regulation (EU) 2022/617 indicates a TWI for inorganic mercury of 4 mg/Kg body weight for all ages groups and gender. Food habits were considered.

 

 

9. The discussion is so simple that I cannot find any novelty and significance compared with the previous studies.

Authors: The discussion has been improved.

 

Round 2

Reviewer 2 Report

Some revisions were performed, however, this work still cannot be accepted in this current form. And the detailed comments are listed as follows:

1. Paper title: “Messina in Italy” must be addressed here.

2. Line 92: hydride system should be “hydride generation system”.

3. Line 98-99: the main advantages should be focused on: free of sample digestion, avoid loss of trace Hg and fast analysis. In fact, “memory effect” is still remained in direct sampling Hg analyzer.

4. Due to the lipophicity of MetHg, the correlation between fat and MetHg should be no problem. However, this study is focused on processed food, in which the composition especially original fat in food has been changed. Furthermore, Hg species analysis was not carried out in this work. So, the conclusion eg. “A significant correlation between fat and mercury content was observed among tuna samples” cannot be drawn so easily. The special study of correlation between fat and MetHg should be performed alone in the future. So, the discussion about this must be revised.

Author Response

Some revisions were performed, however, this work still cannot be accepted in this current form. And the detailed comments are listed as follows:

 

1. Paper title: “Messina in Italy” must be addressed here.

Authors: The correction has been made.

 

2. Line 92: hydride system should be “hydride generation system”.

Authors:  The correction has been made.

 

3. Line 98-99: the main advantages should be focused on: free of sample digestion, avoid loss of trace Hg and fast analysis. In fact, “memory effect” is still remained in direct sampling Hg analyzer.

Authors: Corrections have been made.

 

4. Due to the lipophicity of MetHg, the correlation between fat and MetHg should be no problem. However, this study is focused on processed food, in which the composition especially original fat in food has been changed. Furthermore, Hg species analysis was not carried out in this work. So, the conclusion eg. “A significant correlation between fat and mercury content was observed among tuna samples” cannot be drawn so easily. The special study of correlation between fat and MetHg should be performed alone in the future. So, the discussion about this must be revised.

Authors: Corrections have been made.