Effects of Lactic Acid and Ascorbic Acid Mixture on Quality Properties of Wild Red Deer (Cervus elaphus) Meat
, Attila Lőrincz 2, Majd Elayan 1, László Friedrich 2, Annamária Barkó 1, Tamás Csurka 2, Anikó Boros 1, Géza Hitka 3,* and Adrienn Varga-Tóth 2
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe article “Effects of lactic acid and ascorbic acid mixture on quality properties of wild red deer meat (CERVUS ELAPHUS) presents a very weak scientific value, and only after thorough correction and completion can it be published in Applied Sciences. The subject of the study was to evaluate the influence of the mixture of LA and AA with the method of spraying on the surface of wild deer meat on meat quality parameters: pH, color, number of bacteria, analysis of texture, and gel electrophoresis. The result of the study was to improve the durability of deer meat during retail exposure in vacuum packaging at a temperature of 4 x 1 °C. The presented studies do not bring new knowledge. The literature used in both Introduction and Results and Discussion is not up-to-date. Most of the cited items are from 10-20 years ago. There is no discussion and current reports. In addition, according to Commission Regulation (EU) No 101/2013; ANNEX; PART I:
Conditions of use of lactic acid to reduce microbiological surface contamination of bovine carcases or half carcases or quarters at the level of the slaughterhouse
2. Lactic acid solutions must:
(a) only be applied on entire carcases or half-carcases or quarters of meat from domestic bovine animals (including Bubalus and Bison species) at the level of the slaughterhouse;
Such provisions in the Commission Regulation (EU) indicate that currently there is no possibility of using LA outside the slaughterhouse and for pieces of meat. What is related to this the conclusion "Consequently, the use of 2% lactic acid and 2% ascorbic acid mixture spray on wild 399 red deer meat may be used in the meat industry to improve the safety standards without any negative impact on the color attributes of fresh meat." is incorrect.
Below are some specific comments on the text presented.
Line 56-58: Owing to these nutritional properties, deer meat consumption is increasing each year, but one of the challenges is the short shelf life due to microbial growth. – is deer meat different than, for example, beef?
Is it possible to determine the state of maturity of meat? This is very important in terms of the dynamics of changes in pH of meat and the formation of its color and texture.
Please provide the parameters of the foil used to pack meat samples (in particular its barrier to gases).
pH determination – was the meat sample ground up or was the measurement made by inserting an electrode into a piece of meat?
The results of measurements should not be compared if the conditions are not similar. In this study, measurements were taken through foils, so a comparison with, for example, the results presented in publication no. 10 (Meat colour was measured at the surface of buffalo meat steaks, 30 min after pack opening, in order to allow colour stabilization on exposure to air) is not meaningful.
It is similar with the analysis of results obtained from the examination of carcasses and meat in pieces (packaged). Due to the different conditions, it is difficult to consider the comparison made as reliable.
Were the meat samples used in the TPA test previously heat treated or conditioned before measurement?
The work did not present the results dE laconically described (line 266-258) the obtained dependencies without specifying by which observer the difference was noticed. One can refer to the research by Mokrzycki at all in which the following criteria were adopted: In the interpretation of the results, it was assumed that: When 0 < ∆E < 1-the observ-er does not notice the difference; when 1 < ∆E < 2-only an experienced observer may no-tice the difference; when 2 < ∆E < 3. 5-an unexperienced observer also notices the differ-ence; when 3. 5 < ∆E < 5-a clear difference in colour is noticed; and when 5 < ∆E-an ob-server notices two different colors (Mokrzycki, WS; Tatol, M. Color difference ∆EA survey. In Proceedings of the Machine Graphic & Vision, Warsaw, Poland, 8 October 2012).
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe sentence "The aim of this work was improvement of red deer meat shelf life using organic acid mixture during retail display under vacuum packaging at 4 ± 1 °C." is unnecessary. The aim of the study was presented in the first sentence. line 100: at what time after slaughter? Important from the point of view of meat maturation. It will affect, among other things, pH and protein profile line 164: please provide the source of the method. Sarcoplasmic proteins are usually extracted with water, and myofibrillar proteins with salts. Although a stronger salt was used for myofibrillar proteins, why was r-r NaCl used for sarcoplasmic proteins? line 177: was the protein concentration brought to an equal level? line 397: "myofibrillar proteins were fragmented and released in the soluble fraction" - this sentence should be rephrased or clarified. Myofibrillar proteins are insoluble, and only after fragmentation do they pass into the soluble fraction? Of course not :) I consider the Results and Discussion chapters to be the best developed fragment of the work submitted for review. The Introduction and Material and Methods chapters are correct, they will be better after the changes sent above are implemented. The Conclusion chapter is correct. The weakest part of the work is the Abstract, which requires editing. I am not an expert in English, so it is not subject to my assessment.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsSpecific comments and suggestions can be found in attached PDF.
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsDear Authors,
My comments are attached.
Comments for author File: Comments.pdf
Minor English editing is required.
Author Response
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Author Response File: Author Response.pdf
Reviewer 5 Report
Comments and Suggestions for AuthorsThe manuscript applsci-3197420 entitled "EFFECTS OF LACTIC ACID AND ASCORBIC ACID MIXTURE ON QUALITY PROPERTIES OF WILD RED DEER MEAT (CERVUS ELAPHUS)"
Overall, the paper is well-written. However, I have few suggestions/recommendations for the improvement.
1) Would it be possible for you to research and incorporate information in the introduction related to the legal aspects of hunting, selling, and consuming venison (deer meat)? This could include details on the previous legal restrictions in the UK and an exploration of the current legal requirements in different regions around the world.
2) I think title should be written in sentence case rather than writing in capital letters. Please recheck journal style and correct it accordingly. I also suggest to replace the deer meat with venison.
3) Keywords: These should be different from the words already appeared in the title. Please replace these words such as ascorbic acid, lactic acid, etc.,
4) Line 55-56: Why they have high unsaturated fatty acid concentration in relation to saturated fatty acids and is an excellent source of long-chain n-3 polyunsaturated fatty acids? Please give reasoning with reference here. For instance, deer spend most time in grazing that might be the reason of high omega-3 content.
5) Line 57-58: Why there is issue of spoilage of deer meat? Please explain it here because the main objective of this study is based on the assumption. Why deer meat is more prone to spoilage compared to other red meats?
6) Line 68-77: I will suggest to cite a recent paper published in meat science related to use of Lactic acid in beef carcasses contaminations.
Manzoor, A., Jaspal, M. H., Yaqub, T., Haq, A. U., Nasir, J., Avais, M., ... & Yar, M. K. (2020). Effect of lactic acid spray on microbial and quality parameters of buffalo meat. Meat Science, 159, 107923.
7) Line 79-80: sentence is incorrect (….for reduce antioxidative activity). Please check it. Ascorbic acid improves oxidative stability because it is good antioxidant. Please check it and correct it.
8) Line 82-88: It is confusing. Typically, we add ascorbic acid to enhance oxidative stability, but the authors seem to indicate that it is actually prone to oxidation. Can you please review and confirm this information? Also, could you rephrase it to make it clearer?
9) Line 99: When they were slaughtered? The time post-mortem the samples were taken?
10) M. semimembranosus muscles. Either remove M. or muscle.
11) Line 109: Vacuum packaging equipment and materials details
12) Why sensory analysis was not performed? I think it should be included if possible. Whenever we introduce something in meat, it is important to conduct sensory analysis. How consumers will perceive this product.
13) Results and discussion: Superscripts are not clear. It is indicating in the rows or in columns? It is treatment effect or storage period? I will strongly recommend to include interaction effects of treatments and storage period, that could be indicated by two types of alphabets. In the rows and columns. It is not clear to the readers.
14) Please include P-values in tables or indicate with stars
15) SDS-PAGE: Why there reducing and non-reducing page was conducted separately? If the SDS-PAGE was only conducted for treated samples, why not for un-treated samples for comparing the effect of LA on proteolysis with untreated samples. Please explain
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsI have no comments
Reviewer 3 Report
Comments and Suggestions for AuthorsNo further comments.
Reviewer 4 Report
Comments and Suggestions for AuthorsDear Authors,
Thank you for your revision. I have no further comments.
