The Effect of Different Frying Methods and the Addition of Potassium Aluminum Sulfate on Sensory Properties, Acrylamide, and Oil Content of Fried Bread (Youtiao)

Round 1

Reviewer 1 Report

English needs serious editing to avoid misleading statements and confusing sentences.

Please see attached file with marked places.

Abstract must be edited to be specific. Please include numeric results too. English needs revision to highlight results. Authors' description now focuses on negative outcomes and without careful reading of details one can have the impression of a failed experiment. Please try removing "when not" structures (see also L169-170 etc.).

Confusing English examples:
- L35: "processing parameter of the pH" the pH itself is the parameter, the pH does not have additional feature what would have been investigated, if any.
- L71-72, L144
- L141: please add the type of youtiao, such as "vacuum fried youtiao ..."

Please use SI units. The 550 mmHg pressure is 73.327 kPa, the 9000 rpm is 9000 1/min. Always put space between number and unit.

The significance level and error level are different, 95 % significance means p<0.05 (see L125).

Please correct "potassium bicarbonate" since this material was not mentioned among ingredients.

Figure 1: can remove G, L, M as size and structure is visible on N and O. Additionally, it will be more clear to have 2 x 3 figures.

L184: please add reference data to the end of the sentence for better clarity.

Table 2 and CIE color data. Delta E must be calculated compared to control. It can show color change as a result of different methods or ingredients. Comparison to white standard does not provide additional information to color coordinates.

Figure 2 must be improved as confidence interval is always symmetric to mean, and therefore middle value must be at the top of the bars.

Table 4: as sensory values were given from 1 to 4, reported scores should be in this range. Please use average instead of sum value. It will be more clear and easy to understand. Changing to average does not affect Duncan's test result, superscript marks can remain. Additionally, Duncan's test could not be performed on single value such as summary.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This study tests the effect of different frying methods on acrylamide content and selected properties of fried bread.

The resubmitted manuscript has been completely improved compared to its previous version. However, it still has some shortcomings. They are listed in the notes to Authors. The manuscript can be published in this journal after minor revision.

 

 

Remarks for Authors

1. Lines 166-167. “Table 1 shows that the pH of youtiao with potassium aluminum sulfate frying in vacuum frier is lower than without potassium aluminum sulfate”.

It is not certain, because in this case the results of statistical analysis are missing.Please add the results of analysis of variance (ANOVA) with parametric test. It allows to see the significance of difference between the mean values.

2. Lines 184-185. “The difference in color (ΔE) and browning index when compared to the standard white plate indicates that when the  youtiao was vacuum fried, there were smaller ΔE values compared with deep-frying and electrostatic frying methods (Table 2)”.

It would be better to compare the difference in color (ΔE) between the control sample and the rest of the samples.

3. Lines 232-234. “Overall results indicated the pH of youtiao with vacuum frying at 120℃ without potassium aluminum sulfate is higher  and the youtiao with traditional frying method without potassium aluminum sulfate contains more acrylamide”.

This is not certain because the results of the statistical analysis are missing.

4. Lines 240-241. “Therefore, these two frying techniques are not recommended for youtiao production even though electrostatic frying is a new technique for reducing frying time and oil absorption in products”.

Which two methods are not recommended for youtiao production? It is unclear from the above description.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

In the article, the authors investigated the influence of different frying methods and the addition of potassium aluminum sulfate on the acrylamide formation, the oil content and sensory properties of fried bread (youtiao). The idea of undertaking this type of research is very interesting because this type of bread is often eaten in many countries, and the method of its production may significantly reduce its digestibility and affect the formation of toxic compounds (e.g. acrylamide). Unfortunately the authors did not fully use the potential of the obtained results, and the reviewed article requires many additions and corrections to be considered for publication - in the current version it is not suitable for publication in Applied Sciences.

 I leave some comments for the authors in the attached file but I would like to emphasize some points:

1. In the introduction, there is too little information about the current state of knowledge regarding the influence of various frying techniques on the acrylamide content, fat content and sensory properties of bread. This results in insufficient understanding of the purposefulness of undertaken research. In this context, it is also worth considering why the authors carried out a sensory analysis of fried bread, since they did not mention it either in the title of the work or for its purpose, while in the conclusions they only mentioned the texture.
2. The authors only quote the results presented in tables or figures, and do not discuss them or don’t analyze the causes of the observed phenomena. The most important example is characteristic of the content of acrylamide and reducing sugars written on the basis of Table 3 (lines 187-194). A comparison of the obtained results with the research of other authors should be used because the lack of such comparisons significantly impoverishes the article and makes its scientific value very low.
3. The sequence of the analytical procedures described in the Materials and methods chapter and the order of parameters presented in tables and figures should be the same.
4. In the Materials and methods section, I suggest the more detailed description of all used analytical procedures, as was done for acrylamide and sensory analysis, and placing them as subsections of Chapter 2. I also emphasize the importance of establishing a uniform sequence of analytically determined components both in the Materials and methods chapter and in the section 3 (Results and discussion).
5. Many sentences in the description of tables and figures do not result from them, e.g. lines 143-146.
6. The description of the results presented in Table 1 (lines 166-171) is illegible and can increase in value if it will be rewritten and the results will be discussed either according to their order in the table or on the basis of their importance in described processes.
7. Some of the text below Table 2 is improperly formatted and exceeds the margins. There is also no information about ΔE and BI parameters placed in the last two columns of this table. Information about these was also not found in the Materials and methods chapter.
8. Apart from the need to conduct a more in-depth analysis of such relationships like the mechanisms of acrylamide formation under the influence of various frying cinditions, it is very important to indicate the reasons why the color measurement using the CIELab method (Table 2) does not coincide with the color of the bread shown in the photographs (Figure 1).
9. In Table 1 and Table 3 some results of the statistical analysis are missing (see the manuscript for details).
10. The conclusions present too little information about the chemical mechanisms of the changes observed during bread frying. The authors should try to understand more deeply the relationship between the frying techniques, their parameters (temperature, time and potassium aluminum sulfate addition) and the acrylamide content, fat absorption and sensory characteristics of bread.
11. The list of references does not contain publications from the last 3 years and should therefore be updated.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

 

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

I am very confused - in most of the manuscript the authors indicate they compared with and without addition of potassium aluminium sulfate, but in the abbreviations for Figs 1 and 2 it suggests it was sodium aluminium sulfate. Which is correct?

I disagree with many of the claims made in the abstract. In line 18 it is claimed that the pH of the youtiao changed significantly but according to the values and statistical analysis shown in Table 1 this is only true for the electrostatic frying method. The difference for deep frying is not significant and the vacuum frying had insufficient replication for analysis. The oil content is said not to be affected by the frying method (line 17), yet in lines 181-182 it states that other methods of frying had higher oil content. However, the oil content data in Fig 2 does not have any statistical analysis - so which is correct? I also believe that if moisture levels differ in the youtiao cooked by different methods then the fat % ought to be calculated on a dry weight basis. 

I do not agree with the statement in line 19-20. In my opinion the results of this study do not suggest there is any basis to believe alternative aluminium acidulants or frying methods will have any effect on acrylamide formation or oil content.

line 29. The maximum recommended intake levels of aluminium are very different between regions. How much youtiao would a Chinese consumer have to eat to reach these limits? Is it possible with typical levels of consumption?

line 41. Please be consistent in what you call each frying method - do not use electrostatic and DENBA interchangeably.

lines 71-74. Details of the method are not required if it is the same as reference [17]

Why is the colourmeter methodology not included?

Line 76. This should indicate that this is how the acrylamide level was determined.

line 80. What is the source of the HLB/MCX cartridge? I do not understand what this sentence implies - should it be that the cartridge was preconditioned with 5mL and 3mL of methanol and DD water, respectively?

line 84. What was the final volume of the concentrate? or was it evaporated to dryness and then redissolved in a volume of something?

line 96. The standard curve for acrylamide is from 1875 ng/mL but the concentration shown in Table 3 is ppb. Is the standard curve sensitive enough to measure ppb?

line 100-103. Is this required since you already cite reference [21 and 22]?

Sensory analysis. Was this carried out on freshly cooked youtiao or was it frozen samples that were thawed and reheated? If so, how was this done, and how would this relate to how youtiao is normally consumed?

line 110. I do not see why the ranking sum of 90 panelists would be used or how it could be statistically analysed when you could calculate the average score and make it easy for the reader to know whether any of the samples were strongly liked or disliked as per the instruction (line 108).

lines 118-123. There are a lot of claims made about whether there are significant differences in colour of samples based on the photographs in Fig 1. The photographs were not analysed by any method to establish colour. Colour should only be determined from colormeter or sensory analysis. 

line 124. It indicates that the youtiao was centrifuged after cooking to remove oil but this was not described in the method. So what is correct?

line 127 and elsewhere. This section is titled 'Results' but it contains some elements of Discussion. Retitle or create a new section for the Discussion.

line 133. The statement "results show that potassium aluminium sulfate reacts with potassium bicarbonate" cannot be supported by the data. Firstly, there is no potassium bicarbonate in the list of ingredients, secondly the effects of sodium bicarbonate on the rise of the product may be indirectly influenced by an effect of potassium aluminium sulfate on the flour at the lower cooking temperature. This (or several other hypotheses) cannot be disproved by the experiment.

Table 2. All the colormeter data show there are no statistically significant differences in Lab values between frying methods or the presence/absence of potassium aluminium sulfate. So, either the analyses are wrong or all that nonsense about colour differences shown in Fig 1 needs to be retracted.

line 198-199. It's claimed that sensory colour score (177) was lowest for the control sample but Table 4 shows a score of 177 for the EA sample too. You cannot selectively pick on certain numbers just to support your hypothesis!

The section titled "Conclusions" is too long and contains elements of Discussion. line 226 makes a claim about "absorbing more ammonia" that is completely inaccurate. Firstly, ammonia was not measured and secondly, all of the dough mixtures contain the same amount of ammonium bicarbonate - so where is it being absorbed from?        

line 249. reference [5] contains superfluous information  

 

    

 

 

Author Response

Ref. No.: processes-656297

Title: The Effect of Different Frying Methods and the Addition of Potassium Aluminum Sulfate on Acrylamide and Oil Content of Fried Bread (Youtiao)

Author(s): Yung-Shin Shyu, Jean-Yu Hwang, Shih-Ting Shen and Wen-Chieh Sung

 

To: Referee 01

 

The authors are extremely grateful to anonymous referee involved for providing his/her excellent comments and valuable advice in this paper. We have revised the paper based on the referee’s comments. Following statements are tabulated as a table, which provide the comparison between the referee’s comments and the authors’ revision. We have pleasure in requesting the referee to review this paper. Thank you. Your prompt attention to this paper will be much appreciated.

 

 

Yours sincerely

 

The authors

Author Response File: Author Response.pdf

Reviewer 2 Report

This study tests the effect of different frying methods on acrylamide content and selected properties of fried bread. The topic is interesting but the study are described sloppy and with errors.

The aim of the work in the introduction is imprecise. There is total chaos in the methods paragraph. It is often difficult to know which parameter or property is being described.

Part of the statistical analysis is missing (tables and figure 2).

The authors state that there is an effect of the method or additive of acrylamide on the measured properties, while the statistical analysis shows that this effect is not statistically significant. The results are incorrectly described and lead to erroneous conclusions.  The work requires formatting in accordance with the requirements of the journal.

 

Remarks for Authors

Line 29 – What is the acceptable level of aluminium intake? Lines 53 – Methods – divide this paragraph into subsections and describe them properly. Lines 153-154 “Table 1 shows that the pH of youtiao with potassium aluminum sulfate is lower (p>0.05) than without potassium aluminum sulphate”. Table 1 shows that there is no statistically significant effect of the addition of potassium aluminum sulphate on pH. Lines 160-162 “Table 1 shows that youtiao fried in a vacuum fryer had significantly lower water activity than deep-fried youtiao and electrostatic frying (Table 1), and had a lower moisture content (p> 0.05)”.Table 1 shows that there is no statistically significant effect of the frying method on moisture content of fried bread (the same letters in columns). Line 169 “Table 2 confirms that youtiao without potassium aluminum would have a lower L and a value (p> 0.05)”.This is not true. There are the same letters in columns in Table 2. Part of the statistical analysis is missing in Tables 1 and 3 There is no statistical analysis in Figure 2. Conclusions - This section should be corrected after improving the description of the statistical analysis of the results.

Author Response

Ref. No.: processes-656297

Title: The Effect of Different Frying Methods and the Addition of Potassium Aluminum Sulfate on Acrylamide and Oil Content of Fried Bread (Youtiao)

Author(s): Yung-Shin Shyu, Jean-Yu Hwang, Shih-Ting Shen and Wen-Chieh Sung

 

To: Referee 02

 

The authors are extremely grateful to anonymous referee involved for providing his/her excellent comments and valuable advice in this paper. We have revised the paper based on the referee’s comments. Following statements are tabulated as a table, which provide the comparison between the referee’s comments and the authors’ revision. We have pleasure in requesting the referee to review this paper. Thank you. Your prompt attention to this paper will be much appreciated.

 

 

Yours sincerely

 

The authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Authors introduce the effect of aluminium containing ingredient on youtiao frying and its quality. The experiment is clear and interesting. Text needs significant improvement in language, descriptions should be more accurate.

Major comments:

abstract could be more attractive communicating positive way, such as lower acrylamide content was found for ... etc. The two main goals of decreased acrylamide and oil content could be more highlighted. it is a bit confusing what is the reference recipe of youtiao? It would be nice to define and explain changes relative to it. Usually it is observed that parameters changed when selected ingredient was not added. introduction could be a bit extended to understand the role of acrylamide and aluminium in human health. Aluminium also should be decreased. authors conclude that "potassium aluminum sulfate reacts with potassium bicarbonate" (see L133) but it is less supported with reference or specific analysis. Please add at least reference. the statistical analysis was performed with p<0.05 level, but several places changes were reported with p>0.05. Please clarify that default hypothesis was changed or correct. Figure 2 shows data with mean (bar) and standard deviation (whiskers). It would be nice to add note to caption to help understanding. Range can be 95% confidence interval, +/- SD range can be +/- 2 or 3 etc. Range is expected to be symmetric around mean, but it is apparently not on figure. Please explain if difference is caused by distribution or correct. it is unclear how oil/fat content was measured.

Specific comments:

L15-16: "increased when the potassium aluminum sulfate was not added". Please change and clarify modification of recipe. Result became worse with modification? See all similar (L18-19, etc.). L26: "acidulants is an" -> "acidulant is an" L32: "modifying the processing of the pH" please clarify. L41-44: please do not mention a specific producer, but the principle of the equipment. L71-72: please clarify. L72: "set at an ambient temperature" -> "kept on ambient temperature" or similar. See all other occurrences. L84: "HPLC and analysis" does it mean "HPLC analysis" or another analysis was performed too? L85: "Acrylamide concentrations of the youtiao were determined" -> "Acrylamide concentration of the youtiao was determined" L87: "Merck, Hitachi" please choose the producer of the equipment, not the reseller. If different producers made the parts, list them in the text. L90: "volume: 20 μm" please correct unit. L93: ";" -> ":" L95-96: "mass range 50-200" please add unit of mass L102: "the average maximum force" please specify the number of repetitions/samples. L123: "when" please choose different term. All similar (e.g. 162,163). L127-128: please correct grammar. L159: "potassium aluminum" please correct to full name of ingredient L169 "a value" is it the standard CIE a* value?

Author Response

Ref. No.: processes-656297

Title: The Effect of Different Frying Methods and the Addition of Potassium Aluminum Sulfate on Acrylamide and Oil Content of Fried Bread (Youtiao)

Author(s): Yung-Shin Shyu, Jean-Yu Hwang, Shih-Ting Shen and Wen-Chieh Sung

 

To: Referee 03

 

The authors are extremely grateful to anonymous referee involved for providing his/her excellent comments and valuable advice in this paper. We have revised the paper based on the referee’s comments. Following statements are tabulated as a table, which provide the comparison between the referee’s comments and the authors’ revision. We have pleasure in requesting the referee to review this paper. Thank you. Your prompt attention to this paper will be much appreciated.

 

 

Yours sincerely

 

The authors

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

There are still areas of concern:

The authors still say there are significant differences in the appearance of the different youtiao samples shown in Fig 1. The word 'significant' implies a level of statistical confidence in such a claim, but there was no data to analyse with a statistical test so it is misleading. Instead the authors could say that there were 'subjective differences in the appearance of the youtiao...'. The lack of statistical differences in the colormeter data (Table 2) only supports the subjective nature of the photographs. Was the statistical analysis done correctly?  I disagree with the wording of lines 167-168 and 187-188 - you cannot say that the values for pH and Lab are lower when the p value is >0.05! Again, the use of language is not supported by the statistical analysis. The use of > and < is not always correct. Also, the authors seem to misinterpret the statistical analysis where subscripts are 'a' and 'ab'. They both have 'a' which means there is no significant difference between the groups and so you cannot say the values are lower (p>0.05) but this is not understood. Where did the new data come from in Table 1 and Table 3 in this version of the manuscript? The previous version did not have SD data for VA and VnA pH or Hardness - but now it is there! Also, the SD for acrylamide and Reducing sugars for these samples is now shown as 0.00 - but previously there was no replication. No replication does not give a SD of 0.00!

Author Response

Dear Reviewer

 

The authors are extremely grateful to anonymous referee involved for providing his/her excellent comments and valuable advice in this paper. We have revised the paper based on the referee’s comments. We have pleasure in requesting the referee to review this paper. Thank you. Your prompt attention to this paper will be much appreciated.

 

Point 1:

There are still areas of concern:

The authors still say there are significant differences in the appearance of the different youtiao samples shown in Fig 1. The word 'significant' implies a level of statistical confidence in such a claim, but there was no data to analyse with a statistical test so it is misleading. Instead the authors could say that there were 'subjective differences in the appearance of the youtiao...'. The lack of statistical differences in the colormeter data (Table 2) only supports the subjective nature of the photographs. Was the statistical analysis done correctly?  I disagree with the wording of lines 167-168 and 187-188 - you cannot say that the values for pH and Lab are lower when the p value is >0.05! Again, the use of language is not supported by the statistical analysis. The use of > and < is not always correct. Also, the authors seem to misinterpret the statistical analysis where subscripts are 'a' and 'ab'. They both have 'a' which means there is no significant difference between the groups and so you cannot say the values are lower (p>0.05) but this is not understood.

 

Response 1:

We have rewritten and deleted the misleading no significant differences (p>0.05) concept through the Abstract, Results and Discussion, and Conclusions sections in our article carefully as red marked texts in the revised manuscript. We are so sorry for the mistakes. Thanks for the suggestions and we appreciate you giving us the second chance. (Please see the revised manuscript).

 

Point 2:

Where did the new data come from in Table 1 and Table 3 in this version of the manuscript? The previous version did not have SD data for VA and VnA pH or Hardness - but now it is there! Also, the SD for acrylamide and Reducing sugars for these samples is now shown as 0.00 - but previously there was no replication. No replication does not give a SD of 0.00!

 

 

Response 2:

Thank you for pointing out the mistake and the comments. We have rechecked our raw data and found the pH for VA and VnA measuring is duplicate and hardness measuring is triplicate. We rewritten and deleted the SD for the explanation of Table 1. The acrylamide and reducing content of is average of 3 samples in Table 3. (Please see the revised manuscript)

 

 

Yours truly,

 

 

 

Wen-Chieh Sung, Ph.D.

Professor

Department of Food Science

National Taiwan Ocean University

 

Author Response File: Author Response.docx

Reviewer 2 Report

The paper can be accepted in present form

Author Response

Dear Reviewer

 

The authors are extremely grateful to anonymous referee involved for providing his/her excellent comments and valuable advice in this paper. We have revised the paper based on the referee’s comments. We have pleasure in requesting the referee to review this paper. Thank you. Your prompt attention to this paper will be much appreciated.

 

Point 1:

The paper can be accepted in present form.

 

Response 1:

Thanks for all the valuable comments. (Please see the revised manuscript).

 

 

 

Thank you for your consideration.

 

 

Yours truly,

 

 

 

Wen-Chieh Sung, Ph.D.

Professor

Department of Food Science

National Taiwan Ocean University

 

Author Response File: Author Response.docx

Reviewer 3 Report

Authors improved the manuscript focusing only on the marked places. English still needs revision, even in new text (see L218-219).

Results are introduced as changes with both p>0.05 and p<0.05. The value p<0.05 means real change generally, since statistical test has lower probability of mistake than adjusted significance threshold. The value p>0.05 is above threshold and in comparison generally means no difference. I assume the same test and same null hypothesis was used all along the manuscript. Please check and correct all. See attached file for marks.

Overall the applied adjustments do not meet the recommended "major revision".

Comments for author File: Comments.pdf

Author Response

Dear Reviewer

 

The authors are extremely grateful to anonymous referee involved for providing his/her excellent comments and valuable advice in this paper. We have revised the paper based on the referee’s comments. We have pleasure in requesting the referee to review this paper. Thank you. Your prompt attention to this paper will be much appreciated.

 

Point 1:

Authors improved the manuscript focusing only on the marked places. English still needs revision, even in new text (see L218-219).

 

Response 1:

We have rewritten and rechecked our article carefully as red marked text in the manuscript. If it is not good enough at this revised manuscript, I will look for help from OmniEnglish to revise the paper again. Thanks for the suggestions and we appreciate you giving us the second chance. (Please see the revised manuscript).

 

Point 2:

Results are introduced as changes with both p>0.05 and p<0.05. The value p<0.05 means real change generally, since statistical test has lower probability of mistake than adjusted significance threshold. The value p>0.05 is above threshold and in comparison generally means no difference. I assume the same test and same null hypothesis was used all along the manuscript. Please check and correct all. See attached file for marks.

 

Response 2:

Thank you for pointing out the mistake and the comments. We have deleted the “p>0.05” through the revised manuscript and rewritten the explanation of Results and Discussion and Conclusions sections. (Please see the revised manuscript)

 

Point 3:

Overall the applied adjustments do not meet the recommended "major revision".

 

Response 3:

We sincerely appreciate your suggestions. Please give us suggestion and hope this revised description could have a great improvement. (Please see the revised manuscript as red colored text).

 

 

 

Yours truly,

 

 

 

Wen-Chieh Sung, Ph.D.

Professor

Department of Food Science

National Taiwan Ocean University

 

Author Response File: Author Response.docx