Effect of Salt Concentration on Flavor Characteristics and Physicochemical Quality of Pickled Brassica napus

Round 1

Reviewer 1 Report

I think is a good paper with some novelty, but major editions are needed. 

The paper needs more details related to the methodology, is important to remember the protocols should be reproducible, in that way, values, parameters, instruments, etc must be reported in the methodology. Also, the discussion needs to be improved, as is now, it is not easy to follow.

Line 77. a section with materials is needed, especially the salt used. Multiple commercial salts can contain NaCl in different % with other salts like KCl, MgCl etc. This needs to be discussed. Even the chemical reactive NaCl has impurities.  

Line 88. Determination of physical and chemical indicators. Please, add more details about the method used for Salinity, Amino acid nitrogen content, and concentration of nitrite, since they are relevant to the paper.

Line 93. wording.

Line 115. More details are needed for the quantification of phenol content. Add extraction time, centrifugation parameters, calibration curve point values, and brand of the instruments used. 

Line 122. Add instrument brand.

Line 134. were the BLS samples analyzed as it? or did the authors use water? 

Line 149. did the authors use an internal standard? please indicate which. Did you confirm the identity of the compounds using LRI? did you use another column to confirm the identity?  Did the authors use LRI plus MS? please indicate this in the document.

Line 153. equation needs clarification related to the sensory thresholds.

Line 169. A reference is needed.

Line 191. Table 1. How do the authors explain the TA, protein content and salinity trend?  G5 value is lower than G1-G4.

Line 195. Section 3.2. Salt assuming NaCl (this needs to be clarified in the document) can interact with phenol compounds, which naturally are acids and can form phenoxides (Phenolates). This can be another statement to support the authors' results. Did the authors measure the pH in each sample? if so, please include those values in table 1.

Line 203. A reference is needed.

Line 239. Table 2. A thought. Acidic amino acids such as Glu and Asp can interact with Na+ directly through ionic interactions. Also, Tyr. So, did the authors find some relationship in this regard? 

Line 262. This section needs a lot of improvements. It is not clear and need more discussion. Figure 4 helps with the understanding, however, more clarification related to the different groups of compounds vs salt content is not easy to follow. I would also highlight the most abundant compounds since they were not quantified. Keep in mind the crossmodal interaction of aroma compounds.  

Line 282. Table 3. The threshold values presented in the table is adding nothing to the table since the compounds were not quantified. Something, that would improve substantially this paper would be the quantification of the compounds, in this way the OAV will be accurate. Please, indicate if the thresholds are in water, air, oil, etc. also the reference.

Some typo mistakes:

Line 134. use mL instead of ml.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The present research work studied the effect of salt concentration on the quality of pickled brassica napus. The finding of this study provides some useful information for the fermentation of brassica napus, however this manuscript is a bit too descriptive, no sufficient reflection and discussion on the obtained results, additionally, there are some problems in the method and result.

1.      The conclusion is not strong enough. After reading this manuscript, it is still not clear to me which salt concentration is the best for the fermentation of brassica napus. Additionally, the conclusion section should not be the repeat of the results.

2.      The effect of salt on the fermentation of LAB on plant materials has been reported extensively, the authors should compare and justified their results with those published papers.

3.      Line 25, the nutritional value was improved? Can you be more specific, what kind of compounds are you referring to? As the “health-promoting compounds” (phenolics) were found to be decreased in this study.

4.      Line 46, “Soy protein is considered to have protein quality”, I don’t understand what do you mean.

5.      Line 48, “BLS are also rich in protein compared to other leafy vegetables”, can you provide reference and solid data to support this point?

6.      Line 84, for the fermentation, did you inoculate LAB? After 7 days of fermentation, did you take any measure to inactivate the microorganism?

7.      Line 152, ROAV should be explained for the first time used.

8.      Line 153, how do you defined the compound contributes the most? The compounds with the highest relative abundance?

9.      In table 1, it is interesting to see that TA contents in G3, G4 and G5 are significantly different, can the authors explain this result?

10.  In figure 1, flavonoids belong to phenolics, it is strange to see that total flavonoids are much higher than total phenols.

11.  The sources of taste and odor threshold values should be provided.

12.  Line 251-252, “The content of bitter amino acids 251 was most prominent in G5. Probably because it used the most salt, making it bitter.” I don’t understand the logic here.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

1. Abstract needs to be updated accordingly with the comments done by the reviewers to the main manuscript. Changes done in the manuscript would impact the Abstract. Please double-check and update it. 

2. Brassica napus must be italicized in the title and the entire document.

3. Keywords need to be improved. e.g. Physicochemical parameters is not a keyword. 

4. Table 3 has a lot opportunities to be improved. I would focus only in compunds that are ROA statistically different throught G1 to G5. It doesn't make sense to present all the values since they are not different accross the samples. all the remaining data can go to supplemental information and just keep the compounds with statistically different.  

4. Resolution of figure 5 needs to be improved, also, please clarify the cluster correlation between G3 and G5.

Reviewer 2 Report

I am happy to see that the authors have addressed all comments. The manuscript has certainly benefitted from all changes.