Addition of Fresh Herbs to Fresh-Cut Iceberg Lettuce: Impact on Quality and Storability

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article studies the alternative of developing a ready-to-eat vegetable-herb mix using fresh-cut iceberg lettuce and herbs (peppermint, oregano, green basil, red basil, and parsley) and storing for 6 days at 5 °C.

The article has originality, but also several experimental details that must be mentioned to validate the results found.

I detail general and particular aspects below.

Strangely, the vegetables (lettuce and herbs) are not sanitized, and it even seems that the lettuce has not been previously washed with tap water. This is the first condition to work with ready-to-eat vegetables. Please, substantiate this appropriately. If the herbs are sanitized and decontaminated on day 0, the antimicrobial effects that are intended to be shown could be enhanced.

The quality assessment could be improved by assigning % of the sample with the symptoms or in the scale (incidence %). There is a lot of dispersion in those indexes used, and no differences could be observed.

For clarity, several details were added in M&M section. Also, the numbers in the X axes of the figures should be replaced by the % of the herbs.

The article must be improved and I recommend major revisions to be published.

M&M

L81-82. Please, indicate if lettuce is washed and/or sanitized.

L87-88: Please, give more details related to the sensorial experiment

L102-103: indicate the size of punctures

L104-106: Please, mention the number of samples used for all experiments with more details. Mention the sample days and/or final day of storage.

L112-119: I suggest that % deterioration values ​​be defined at each level of the scale. This will allow for less dispersion in the assignment of levels.

L124-150: Please, define the size of the sample used (required to maintain the % of herb). ¿Was an entire tray used for each extract? Please, detail the weight of the sample and the volume of solvent.

L137-139: Check and mention the correct addition order and concentration of the reagents.

L143: The extraction methodology is missing. Please, mention it

L149: Check the wavelength

L170: you mention that microbiological analysis was done at day 3. Please, inform this sample date in section 2.2

L178-180. Number of repetitions?

RESULTS:

L191-195: No data of weight loss was shown. Please, add a graphic or table.

L198-201. rewrite according to statistical results (several data share letter c)

L231-248: these details should be reported as a table footnote.

L265-271: mention the storage day on which the analysis was done

L277-281. comment % or relatives times/fold increment as in the previous paragraphs.

L303: log 10 is repeated. delete one of them

Fig 3C: the vertical line of control is missed.

L320-322: Rewrite for clarity “This was particularly evident in the case of mold…”

L322-325 Rewrite correctly. “Parsley inhibited mold growth…”. The dispersion of 0d is very high and there is no difference between 0d and 3d. Therefore, not only parsley inhibits molds.

DISCUSSION

L362: Please, show data with figure or table in Results section.

Author Response

The authors' team thanks the reviewers for their corrections, comments, and suggestions. In response, we are sending two files, one with marked changes and the other with unmarked changes.

Below are the explanations for each point. In the place of changes  (line number) in the text, I refer to MS with marked changes.

Response to reviewer 1.

1. Strangely, the vegetables (lettuce and herbs) are not sanitized, and it even seems that the lettuce has not been previously washed with tap water. This is the first condition to work with ready-to-eat vegetables. Please, substantiate this appropriately. If the herbs are sanitized and decontaminated on day 0, the antimicrobial effects that are intended to be shown could be enhanced.

• In production, most often cut vegetables are disinfected, but the premise of this research was not to use chemicals. This was supposed to be a study conducted on organically grown plant material, but lettuce, despite good growth and well-developed heads, had strongly developed Tip-burn and was replaced with material from integrated farming, while herbs were left organic. The herbs were washed with clean water, while as for the lettuce, the leaves from the inner part of the head, which were not exposed to the direct environment during cultivation, were taken for testing. As with head cabbage, this is a common practice when cutting head lettuce  –  L 89-92

2. The quality assessment could be improved by assigning % of the sample with the symptoms or in the scale (incidence %). There is a lot of dispersion in those indexes used, and no differences could be observed.

• Scoring scales have been revised – L 135 -148

3. The article must be improved and I recommend major revisions to be published

• The article has been proofread and corrected by a native speaker (proof-reading UK) before being sent to the editors.

4. In the X axes of the figures should be replaced by the % of the herbs.

• At the time of writing the article, we tried with full descriptions on the X-axis, that is, the % of the herb and its name. However, this looked rather bad, especially in the multiple figure 1. The descriptions overlapped. It started to look clearer after we introduced short labels with numbers and descriptions below the figure. However, if the reviewer maintains his suggestion, we will try to do it somehow.

For clarity, several details were added in the M&M section. Also, the numbers

L81-82: Please, indicate if lettuce is washed and/or sanitized.

Corrected – L 89-92

L87-88: Please, give more details related to the sensorial experiment

Corrected – L 99-105

L102-103: Indicate the size of punctures

Corrected L – 118

L104-106: Please, mention the number of samples used for all experiments with more details. Mention the sample days and/or final day of storage.

Corrected L 119-124

L112-119: I suggest that % deterioration values ​​be defined at each level of the scale. This will allow for less dispersion in the assignment of levels.

Percentages have been added to the rotting scale, but from level 5 onward, lower levels are scored based on the number of small decay points.

L124-150: Please, define the size of the sample used (required to maintain the % of herb). ¿Was an entire tray used for each extract? Please, detail the weight of the sample and the volume of solvent.

Corrected L 156 -165

L137-139: Check and mention the correct addition order and concentration of the reagents.

Corrected L 164-165

L143: The extraction methodology is missing. Please, mention it

Corrected L 178-180

L149: Check the wavelength

According to our chemists, 244 nm is correct

L170: you mention that microbiological analysis was done at day 3. Please, inform this sample date in section 2.2

Information is provided in section 2.2 L 119-124

L178-180. Number of repetitions?

Corrected L 208

RESULTS:

L191-195: No data of weight loss was shown. Please, add a graphic or table.

Corrected L 226 -229

L198-201: Rewrite according to statistical results (several data share letter c)

Corrected L 235-236

L231-248: These details should be reported as a table footnote.

Corrected L 265-267

L265-271: mention the storage day on which the analysis were done

Corrected L 308

L277-281: Comment % or relatives times/fold increment as in the previous paragraphs.

Corrected  L 308 – 309

L303: Log 10 is repeated, delete one of them

Corrected L347

Fig 3C: The vertical line of control is missed.

The value for the control is 0 and therefore the bar is missing

L320-322: Rewrite for clarity “This was particularly evident in the case of mold…

 Corrected 362 – 375

L322-325 Rewrite correctly. “Parsley inhibited molds growth…” . The dispersion of 0d is very high and there is no difference between 0d and 3d. Therefore, not only parsley inhibits molds

Corrected  L373-375

DISCUSSION

L362: Please, show data with figure or table in Results section.

The data shown in Table 1 L 226 -229

Reviewer 2 Report

Comments and Suggestions for Authors

1. Have the experimental samples been processed before? For example, cleaned?

2. line 99, transparent polypropylene boxes, is this kind of packaging common for cut vegetables? Please provide photos of packaged vegetables.

3. Experimental data should be compared and discussed with previous literature.

Author Response

The authors' team thanks the reviewers for their corrections, comments, and suggestions. In response, we are sending two files, one with marked changes and the other with unmarked changes.

Below are the explanations for each point. In the place of changes  (line number) in the text, I refer to MS with marked changes.

The corrections suggested by reviewer 2 were made in the text with marked changes in the following lines:

 Abstract: 22; 22-23; 27-31

1. Introduction: 50; 58-68, Deleted sentence – L 73-75

4.2. Setting up storage experiment: 99-106

2.3. Quality Assessment: 135 – 148; 161-163

2.6.  Microbiological Analysis: L206;208

3.1 Results, Weight loss, and storage Ability of mixes of fresh-cut iceberg lettuce with fresh-cut Herbs:

-  A table with weight losses has been added L226 – 229; 240-241;

Correction in L 240-241

- the meaning of the letters is explained in the description under Table 2

Text 273 - 290 has been removed, as these data refer to the table description and have been moved to these places. As for traits affecting commercial value, these are both wilting rotting and browning. In the current study, for 6 days at 5°C, visible wilting and rotting did not occur (L 230 - 231), so browning had the effect of lowering the marketable value.

Reviewer 3 Report

Comments and Suggestions for Authors

The article entitled "Fresh Herbs Addition to Fresh-Cut Iceberg Lettuce: Impact on Quality and Storability" contains valuable information regarding the production of ready-to-eat salads. However, there are some comments mentioned in the attached file that help to improve the scientific content of the article and address existing flaws.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

It is recommended to check the article once again for grammar or syntax errors.

Author Response

The authors' team thanks the reviewers for their corrections, comments, and suggestions. In response, we are sending two files, one with marked changes and the other with unmarked changes.

Below are the explanations for each point. In the place of changes  (line number) in the text, I refer to MS with marked changes.

1. Have the experimental samples been processed before? For example, cleaned?

• In production, most often cut vegetables are disinfected, but the premise of this research was not to use chemicals. This was supposed to be a study conducted on organically grown plant material, but lettuce, despite good growth and well-developed heads, had strongly developed Tip-burn and was replaced with material from integrated farming, while herbs were left organic. The herbs were washed with clean water, while as for the lettuce, the leaves from the inner part of the head, which were not exposed to the direct environment during cultivation, were taken for testing. As with head cabbage, this is a common practice when cutting head lettuce –  L 89-92

2. Line 99, transparent polypropylene boxes, is this kind of packaging common for cut vegetables? Please provide photos of packaged vegetables.

The photo was introduced L 125 -128. These packages are dedicated to food.

3. Experimental data should be compared and discussed with previous literature.

The discussion has been only slightly supplemented, as there is little research on the stability of freshly cut herbs and the nutritional and microbiological quality during shelf life. There is a lot of research on the effect of plant essential oils on vegetable quality but this is a separate topic.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I thank the authors for the revisions made.

First of all, I would like to clarify to the authors that the use of NaClO is not the only sanitizer alternative to use on fresh cut vegetables. There are other alternatives and recommended for organic vegetables. If in future trials, you use any of these methods to disinfect the herbs, you will be able to show their antimicrobial power. And the other aspect to take into account is that the boxes with a lid should be "not perforated". You should use a passive modified atmosphere to be able to contain the volatiles of the aromatic herbs within the container.

I have reviewed the changes, and I still believe that some of them would be modified and/or corrected. Below I detail them.

-In the X axes of the figures should be replaced by the % of the herbs. I send an image with a suggestion. You can even overlap the figures and avoid detailing the X axes in each figure.

-L166: Please, mention that the supernatant was collected.

-L166-168: Check and mention the correct addition order and concentration of the reagents. You mention:

-“Diluted phenolic extracts (0.4 mL), ……if you diluted the extract, please detail how (the relation used).

-were mixed with 1.6 mL of sodium carbonate solution (7.5 %)……usually, the extract is mixed at first time with Folin&Ciocalteau reagent an after few minutes (3 min), sodium carbonate solution was added. Also, sodium carbonate solution is prepared in NaOH 0,1 mol/L.

-Then, Folin–Ciocalteu’s phenol reagent (2 mL) was added and the mixture was shaken”….Usually, the reagent is diluted with water.

-L177: Usually, the wavelength used is: 254 nm. Please, check it

-L178-179: Please, mention the extraction methodology prior to determination by HPLC. Furthermore, mention that the supernatant was collected.

-L228, 246, 266: Please, check the number of samples analyzed. You said: “Values are means of 12 samples ± standard deviation (SD)”. It needs to be mentioned in M&M section, because the number 12 seems not to be appropriate with what is mentioned in line 119-121.

-Fig 3C: The vertical line of control at day 3 is missed.

-L356-357: Please, check it: “Each sample has a total weight of 100 g”. in M&M section (L201), you said 25g

- Typing errors must be corrected: L368: nymber; L372: milds; L377: od

Author Response

Authors thank you for your great effort in reviewing the manuscript

Comments and Suggestions for Authors

First of all, I would like to clarify to the authors that the use of NaClO is not the only sanitizer alternative to use on fresh cut vegetables. There are other alternatives and recommended for organic vegetables. If in future trials, you use any of these methods to disinfect the herbs, you will be able to show their antimicrobial power. And the other aspect to take into account is that the boxes with a lid should be "not perforated". You should use a passive modified atmosphere to be able to contain the volatiles of the aromatic herbs within the container.

• Of course, in the future it would be a good idea to test different ways of disinfecting salads (chemical and physical) in terms of their impact not only on microbiological quality but also on sensory, storage and nutritional quality. As for packaging, our study deliberately used perforated boxes to prevent possible oxygen depletion (due to respiration of plant material) and the onset of anaerobic respiration, which leads to spoilage of plant material. Also in the future, it would be good to check the effect of different types of packaging, including those with micro perforations, on the quality of vegetable and herb salads.

I have reviewed the changes, and I still believe that some of them would be modified and/or corrected. Below I detail them. 

-In the X axes of the figures should be replaced by the % of the herbs. I send an image with a suggestion. You can even overlap the figures and avoid detailing the X axes in each figure.

- the figures have been corrected according to reviewer suggestion, page 9 and 12

All other corrections in the text have been highlighted in yellow

-L166: Please, mention that the supernatant was collected.

 - the information was added

-L166-168: Check and mention the correct addition order and concentration of the reagents. You mention:

-“Diluted phenolic extracts (0.4 mL), ……if you diluted the extract, please detail how (the relation used).

-were mixed with 1.6 mL of sodium carbonate solution (7.5 %)……usually, the extract is mixed at first time with Folin&Ciocalteau reagent an after few minutes (3 min), sodium carbonate solution was added. Also, sodium carbonate solution is prepared in NaOH 0,1 mol/L.

-Then, Folin–Ciocalteu’s phenol reagent (2 mL) was added and the mixture was shaken”….Usually, the reagent is diluted with water.

- the addition order and concentration of the reagents have been corrected according to the method. Line171 – 174

-L177: Usually, the wavelength used is: 254 nm. Please, check it

 -  the chemists who performed these analyses claim that the wavelength specified is correct and they add that in the literature, we can find various information about the wavelength for determining ascorbic acid. Some of them indicate the wavelength of 244 nm as the maximum (Konopacka ans Markowski 2004). In our publication, in the description of the methodology for determining ascorbic acid, the correct wavelength that was used during the analysis is entered, i.e. 244 nm. (Konopacka D., Markowski J. Retention of ascorbic acid during apple chips production and storage. Pol. J. Food Nutr. Sci. 2004, 13/54, 3, 237-241).

-L178-179: Please, mention the extraction methodology prior to determination by HPLC. Furthermore, mention that the supernatant was collected.

  - The description has been changed as indicated. Line 179-181

-L228, 246, 266: Please, check the number of samples analyzed. You said: “Values are means of 12 samples ± standard deviation (SD)”. It needs to be mentioned in M&M section, because the number 12 seems not to be appropriate with what is mentioned in line 119-121.

- the information was completed in M&M. Lines  119-126

-Fig 3C: The vertical line of control at day 3 is missed.

- data for the control is 0 and there is no bar because it overlaps with the X axis

-L356-357: Please, check it: “Each sample has a total weight of 100 g”. in M&M section (L201), you said 25g

- the information was completed. Lines 366-367

- Typing errors must be corrected: L368: nymber; L372: milds; L377: od

- the errors have been corrected, lines 379, 383, 388.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have made the necessary corrections. The paper in its current format is acceptable for acceptance.

Author Response

Comments and Suggestions for Authors

The authors have made the necessary corrections. The paper in its current format is acceptable for acceptance.

• The authors thank the reviewer for performing the review and accepting the manuscript for publication