Water Extracts of Cruciferous Vegetable Seeds Inhibit Enzymic Browning of Fresh-Cut Mid Ribs of Romaine Lettuce

Round 1

Reviewer 1 Report

The analysis of the scientific work "Water Extracts of Cruciferous Vegetable Seeds Inhibit Enzymic Browning of Fresh-Cut Mid Ribs of Romaine Lettuce" addresses the use of aqueous extracts from cruciferous vegetable seeds to inhibit enzymatic browning in fresh-cut stalks of Romaine lettuce. The research identifies the anti-browning properties of cabbage and wild rocket seed extracts, comparing them with metabisulfite controls, and evaluates the impact of exposure time to the extracts on the development of browning during storage. Presenting interesting elements for publication, however, modifications must be made for acceptance.

Positive Points:

- The research addresses a significant problem in the food industry - enzymatic browning in fresh-cut fruits and vegetables. The search for alternative and natural solutions to preserve food quality is essential to meet consumer demands for fresh products without chemical additives.

- The study uses a series of chromatographic and visual analyses to evaluate browning, in addition to testing different concentrations and exposure times. This allows for a detailed understanding of the effects of the extracts on enzymatic browning.

- The application of analysis of variance (ANOVA) and Pearson correlation to assess the data provides a strong statistical basis for the conclusions drawn. This helps to validate the results and ensures reliability.

- By utilizing by-products of cruciferous vegetables, the study offers a sustainable approach to waste management, in addition to potentially reducing the use of chemical preservatives in food.

Critical Points for Counterargument

- Although the study explores different concentrations, a broader range of dilutions could identify the most precise optimal concentration for the inhibition of enzymatic browning. Why did you choose this concentration? Make it clear to the reader.

Methodology

- The description could include specific information about the homogenization process, such as the temperature during homogenization and whether any steps were taken to prevent oxidation during this process.

- Specifying the exact conditions of centrifugation (such as the temperature and the model of the centrifuge) would help ensure the replicability of the prepared extracts.

- Detailing the reference standards used in the analyses of phenolic compounds and antioxidant activity, as well as the origin of these standards, could assist in interpreting the results.

- Although the study mentions the use of a visual index to assess browning, additional details on how these evaluations were standardized among the evaluators could help understand the objectivity of the method. Or was it just one evaluator? Another point: Information on how the consistency and quality of the extracts were checked between different batches of preparation would be useful, especially if there is natural variability in the seeds used.

- While it mentions the use of ANOVA and Pearson correlation, additional information on the treatment of the data before statistical analysis, the justification for choosing specific statistical tests, and how interactions between factors were analyzed could offer a clearer view of the analytical process. For example, were all the data normal, hence the use of Pearson? You could use Spearman.

- Make it clear at all stages how many times the experiments were replicated.

Figures

Figures 1 and 2. Correct the spelling error in axis 2;

Figure 2. Highlight the days (bold) to draw attention;

Figure 5. – Place the variances between the bars (a, b, c or Ab, Aa...) to show statistical significance.

Limitations Discussion:

- The study is conducted under controlled conditions, which may not fully reflect the real-life storage and handling conditions. Additional tests under varying conditions would be beneficial.

- While comparing the extracts with metabisulfite controls, the research could benefit from including other natural browning inhibition methods for a more comprehensive comparison. Beyond this issue, bring a discussion to demonstrate the limitation of this matter concerning toxicity.

- Comment after reading. The study could delve deeper into identifying the specific compounds responsible for the inhibition of browning, which would help better understand the mechanisms involved. Make this clear in the article's limitations in the discussion, regarding perspectives.

- I am not qualified to evaluate the English, however, the text has errors that need to be reviewed. For example, to help, I made a correction in the introduction:

1. "suffer by tissue browning" - A more accurate phrasing would be "suffer from tissue browning."

2. "is influenced predominately by polyphenoloxidase (PPO) and secondarily peroxidase (POD)" - It could be clearer as "is predominantly influenced by polyphenoloxidase (PPO) and secondarily by peroxidase (POD)."

3. "which generates phenolic substrates by catalyzing phenylalanine into cinnamic acid" - This could be rephrased for clarity to "which catalyzes phenylalanine into cinnamic acid, generating phenolic substrates."

4. "as colour is a significant attribute of food which influences consumer decision and brown foods are seen as spoiled" - This could be restructured for better flow: "since color significantly influences consumer decisions and browned foods are perceived as spoiled."

5. "Sulfites have been used as food additives are industrially used to inhibit PPO-induced browning reactions" - This sentence is awkward and could be corrected to: "Sulfites, used as food additives, are industrially employed to inhibit PPO-induced browning reactions."

6. "The dramatic growth of fresh-cut produce market, is a result of consumer demand" - The comma after "market" is unnecessary.

7. "other than chemical approaches to prevent tissue browning of fresh-cut fruits and vegetables are being implemented" - This sentence is confusing. A clearer version could be: "Approaches other than chemical ones are being implemented to prevent tissue browning in fresh-cut fruits and vegetables."

8. "High CO2 modified atmosphere storage (80%N2, 20% CO2) in combination with proper film to wrap the retail packages has been successfully implemented" - For clarity, consider: "The use of high CO2 modified atmosphere storage (80% N2, 20% CO2), combined with appropriate wrapping films for retail packages, has been successfully implemented."

9. "even though, some of these methods" - Remove the comma for correct punctuation: "even though some of these methods."

10. "are characterized by increase phenolic compounds content and antioxidant activity" - Should be "are characterized by increased phenolic compound content and antioxidant activity."

11. "which has been used to stabilize refrigerated avocado pulp" - This phrase might be clearer as "which has been utilized to stabilize refrigerated avocado pulp."

12. "Due to the impact of browning caused by PPO in the food industry, research on potential inhibitory compounds is continuing till today." - Could be more succinctly phrased as: "Due to PPO-induced browning's impact on the food industry, research into potential inhibitory compounds continues."

Author Response

Please see the aattachement

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments to the Authors

The manuscript “Water Extracts of Cruciferous Vegetable Seeds Inhibit Enzymic Browning of Fresh-Cut Mid Ribs of Romaine Lettuce” is well written, and the results provided are scientifically sound.

Here are my detailed comments:

Highlights

-        “visual browning index correlated with browning index.” Please rewrite this sentence, it is not so clearly stated.

Introduction

-        Lines 51-52: Sulfites, used as food additives, are industrially used to inhibit PPO-induced browning reactions for a wide range of products [10].

-        Line 71: “prevention of enzymatic browning of pear by onion extract” should become “pear by onion extract”

-        Please better state the novelty of this research, and how the authors want to contribute to the advancement of the knowledge on the topic. Also better highlight the reasons why those types of seeds have been selected, what are their characteristics and main composition and bioactive compounds.

Materials and Methods

-        Line 123: Remove “a”.

-        Line 126: were expressed in

-        Lines 142 and 149, please introduce the equations in the form of an equation,  not as a text.

-        Lines 166-169, please the same as before. All the equations should be numbered.

-        Lines 175-177: Uniform the font and the size.

Results and discussion

-        Section 3.2. Uniform the font and size.

-        Line 236: Shelf-life

-        Line 251: Substitute the ; with .

-        Line 291: State the meaning of the acronym PCA.

-        Figure 3 and Figure 4, place the legend in the graph that appears as first.

-        Figure 5: adjust the y axis in shelf-life

-        I suggest to add the statistical analysis at least between the VSI values of 10% and 20% of each extract, the same for the BI values.

Conclusions

-        Conclusions can be improved by adding and discussing the main challenges or drawbacks to be faced and possible future perspectives.

Comments for author File: Comments.pdf

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

To Editor and authors,

Oxidation processes occur in both food and non-food items. Enzymic browning is a reaction requiring the presence of enzymes as well as oxygen. It is common knowledge that they promoted physiological deterioration, biochemical changes, and microbial degradation.

The article is interesting, however the presentation of results is unclear, as is the comparative scientific debate. The bibliographic references are not only badly formatted and maintained, but they are also outdated. To increase the quality of a research work, it is necessary to compare it to other similar studies. This work lacks scientific, demonstrative, and comparative information. In my perspective, the article requires major modifications, not just in displaying the results, but also in supporting them. On the other side, bad formatting indicates that the authors were negligent.

In summary, the work should not be considered suitable for publishing and requires extensive reworking.

Comments for author File: Comments.pdf

The quality of English is satisfactory.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The authors took into consideration all the suggested changes, which significantly enhanced the quality of the work.

Therefore, I consider the article suitable for publication.