Aromatic and Nutritional Composition of Edible Flowers of Garden Garlic and Wild Leek

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article titled "Aromatic and nutritional composition of edible flowers of garden garlic and wild leek", by Telmo Marcelo Zambrano Núñez, Adriana Margarita Morales Noriega, María Dolores García-Martínez, and María Dolores Raigón Jiménez, is a study that addresses the aromatic and nutritional composition of the edible flowers of garden garlic (Tulbaghia Violacea) and wild leek (Allium ampeloprasum). Considering the growing interest in natural and functional foods, this research holds significant relevance for the fields of nutrition, gastronomy, and food science. The focus on the presence of organosulfur compounds and antioxidants adds value to the study, as these compounds are associated with health benefits.

A positive aspect of the study is that it explores a little-studied niche of edible flowers, contributing to dietary diversification and employing robust analytical methods to assess nutritional composition and aromatic profile. Furthermore, it aligns with the global trend of seeking natural and healthy foods. The research is well-structured, and the methods are appropriate, but some aspects could be further explored, such as sensory acceptance, bioavailability of bioactive compounds, and the economic impact of producing these flowers.

Introduction: Include more comparative references to justify why these two species were chosen and how this study differs from previous research.

Methodology: There is no detailed information on the exact number of samples and repetitions, which may affect reproducibility. Additionally, the bioaccessibility and bioavailability of bioactive compounds were not analyzed, which would be relevant for a better understanding of their health effects.

Results: A comparison with other edible flowers would help contextualize the findings better, and the inclusion of sensory tests would allow for an evaluation of consumer acceptance.

Discussion: The authors should provide more details on potential challenges for the commercialization of these flowers and their economic viability. Furthermore, optimizing cultivation and post-harvest processes could add more value to the study.

Author Response

Response to Reviewer 1 Comments Article titled "Aromatic and nutritional composition of edible flowers of garden garlic and wild leek". Authors: Telmo Marcelo Zambrano Núñez, Adriana Margarita Morales Noriega, María Dolores García-Martínez, and María Dolores Raigón Jiménez

Thank you very much for taking the time to review this manuscript and for the contributions that will undoubtedly contribute to improving its quality. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted file. The authors would like to thank the reviewer for his words. We are convinced that the field of edible flowers is a very interesting line of research and we are working with other species to expand this area of knowledge. The sensory evaluation study has been planned, but the bureaucracy to authorize the study by the university ethics committee is limiting this work.   Comments 1: Introduction: Include more comparative references to justify why these two species were chosen and how this study differs from previous research. Response 1: The descriptive part of the studied species has been changed from Experimental Materials to Introduction, following the instructions of the second reviewer and the following text has also been included, to justify the study: Edible flowers are gaining significant recognition in global cuisine. Many chefs employ flowers such as pansies and roses to add fragrance and flavour to food and drinks, or simply to make visually simple dishes more appealing [1,18]. The edible potential of some species has been thoroughly evaluated in knapweed (Centaurea cyanus L.) [19], chrysanthemum (Chrysanthemum morifolium Ramat.) [20,21], hibiscus (Hibiscus rosa-sinensis L.) [22], lavender (Lavandula pedunculata Cav.) [23], pansy (Viola × wittrockiana Gams) [24] and pink (Rosa spp.) [25]. Even in flowers of horticultural species such as pumpkin (Cucurbita moschata Duchesne cv ‘Tromboncino’) [26] or onion [17], but they have not been described from wild species belonging to the genus Allium. The study of these wild species and specifically of their flowers holds significant relevance for the fields of nutrition, gastronomy, and food science. Comments 2: Methodology: There is no detailed information on the exact number of samples and repetitions, which may affect reproducibility. Additionally, the bioaccessibility and bioavailability of bioactive compounds were not analyzed, which would be relevant for a better understanding of their health effects. Response 2: Line 161 indicates the number of plants used to obtain the flowers. And line 236 indicates the number of repetitions (tripling). In addition, the tables include the value n=3. It is true that the bioaccessibility and bioavailability of the bioactive compounds have not been analyzed. In this work we have focused on evaluating their agronomic potential and composition. This is a task that we may possibly address in future work that we are carrying out. The authors thank the reviewer for this observation and we will take it into account in future work. Comments 3: Results: A comparison with other edible flowers would help contextualize the findings better, and the inclusion of sensory tests would allow for an evaluation of consumer acceptance. Response 3: This part of comparison with other edible flowers has been included in the discussion. Comments 4: Discussion: The authors should provide more details on potential challenges for the commercialization of these flowers and their economic viability. Furthermore, optimizing cultivation and post-harvest processes could add more value to the study. Response 4: It is true that there has not been much discussion on these aspects, but we consider them to be very interesting, as well as new challenges for continuing to work along these lines, and we have raised this issue in the conclusions.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Article

Aromatic and nutritional composition of edible flowers of garden garlic and wild leek

Herein, the authors conducted a studied on the chemical composition and biological properties of flowers of Tulhia violacea Harv. and Allium ampeloprasum L. with the aim of promoting their as foods containing natural bioactive compounds in their flowers, suggesting them new sustainable cultivation alternatives.

COMMENTS

1) In point 2.1. Experimental Materials. The first paragraph (" Plants belonging to...") should be moved to the introduction appropriately rewritten in a shorter form, it provides a description of the species and does not correspond to this section.

2) 2.3. Volatile Profile Analysis

a) “The determination of the volatile fraction from flowers was carried out using gas chromatography-mass chromatography (GC-MS)”

Please revise, and change by “Gas Chromatography-Mass Spectrometry (GC-MS) 

b) Regarding: “Finally, for quantification, a total ion current chromatogram was employed to integrate the peak area of each compound [24].

Please revise the reference included [24], I think that no correspond here:  Knudsen, J.T.; Eriksson, R.; Gershenzon, J.; Ståhl, B. Diversity and distribution of floral scent. Bot. Rev., 2006, 72, 1. https://doi.org/10.1663/0006-8101(2006)72[1:DADOFS]2.0.CO;2

In addition, The relative proportion of each compound is determined as a percentage of the TIC, please indicate o describe as was realized the quantification ?

3) 2.4. Data Analysis “Three replicates were used to obtain the mean values for nutritional, total antioxidant activity, total polyphenolic…”

Please note that the expression "total antioxidant activity" is not accurate, as only DPPH capture was assayed, and this method does not encompass all possible antioxidant activities. Antioxidants play a crucial role in reducing oxidative stress. Various methods are used to inhibit oxidation by these antioxidant compounds, each with its unique advantages and limitations, contributing significantly to the fields of food science and healthcare. To generalize and use total antioxidant activity, is necessary to assay various methods; in this case, the authors can refer to "antiradical activity." Considered that assays applied to determine the antioxidant capacity of complex samples, are  based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin–Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test, and the [2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl] (DPPH) test.

3. Results

In run 3, revise :  polyphenols

In all text, please revise that name of plants are in italic  (A. ampeloprasum and  T. violacea)

Regarding to ”Coefficients of variability (CV) showed a wide range of values in the nutritional parameters. In general, garden garlic flowers had lower coefficients of variability than those shown by the parameters of wild leek flowers.”

The authors conducted an interesting study of the flowers of two species of  the liliaceae family to suggest them as edible, but the comparison between the species could indicate a distortion for the interpretation of the results.

I suggest reanalyzing data in each assay, data were expressed as fresh weight material. Since the moisture content varies among the flower samples, the comparative analysis is not valid. If results expressed as dry weight material, then comparisons between the samples of the flowers both species are acceptable.

Author Response

Response to Reviewer 2 Comments Article titled "Aromatic and nutritional composition of edible flowers of garden garlic and wild leek". Authors: Telmo Marcelo Zambrano Núñez, Adriana Margarita Morales Noriega, María Dolores García-Martínez, and María Dolores Raigón Jiménez

Thank you very much for taking the time to review this manuscript and for the contributions that will undoubtedly contribute to improving its quality. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted file. Comments 1: 1) In point 2.1. Experimental Materials. The first paragraph (" Plants belonging to...") should be moved to the introduction appropriately rewritten in a shorter form, it provides a description of the species and does not correspond to this section. Response 1: Done. This section has been moved to the introduction and supplemented with suggestions from reviewer 1. Comments 2: 2.3. Volatile Profile Analysis a) “The determination of the volatile fraction from flowers was carried out using gas chromatography-mass chromatography (GC-MS)” Please revise, and change by “Gas Chromatography-Mass Spectrometry (GC-MS). Response 2: I totally agree. It's a mistake. Done. b) Regarding: “Finally, for quantification, a total ion current chromatogram was employed to integrate the peak area of each compound [24]. Please revise the reference included [24], I think that no correspond here:  Knudsen, J.T.; Eriksson, R.; Gershenzon, J.; Ståhl, B. Diversity and distribution of floral scent. Bot. Rev., 2006, 72, 1. https://doi.org/10.1663/0006-8101(2006)72[1:DADOFS]2.0.CO;2 Totally agree. It's a mistake. Reference 24 replaced with the one that actually relates to quantification. In addition, The relative proportion of each compound is determined as a percentage of the TIC, please indicate o describe as was realized the quantification ? Done. Line 232 includes the following text: The relative proportions of each compound having been calculated from the peak area of the total ion current signal on the mass spectrometer. Comments 3: 2.4. Data Analysis “Three replicates were used to obtain the mean values for nutritional, total antioxidant activity, total polyphenolic…” Please note that the expression "total antioxidant activity" is not accurate, as only DPPH capture was assayed, and this method does not encompass all possible antioxidant activities. Antioxidants play a crucial role in reducing oxidative stress. Various methods are used to inhibit oxidation by these antioxidant compounds, each with its unique advantages and limitations, contributing significantly to the fields of food science and healthcare. To generalize and use total antioxidant activity, is necessary to assay various methods; in this case, the authors can refer to "antiradical activity." Considered that assays applied to determine the antioxidant capacity of complex samples, are  based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin–Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test, and the [2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl] (DPPH) test. Response 3: Done. Comments 4: Figure 1. Line 49-50. Please adjust the figure title/description to better explain what is being shown in the 3 images. Suggest labelling the 3 images as A, B, and C and then including this in the figure title/description along with a more detailed explanation. Response 4: I totally agree. Many thanks to the reviewer for the very complete comment. The expression “total antioxidant activity” has been changed to “antioxidant activity by DPPH assay” throughout the text. Comments 5: In run 3, revise :  polyphenols Response 5: Data provided for polyphenols are the ranges of the minimum and maximum recorded for each type of flower. The average value is the data shown in table 1. In addition, the percentage difference between both contents appears, obtained by difference of the average, with respect to the highest value, which is that of A. ampeloprasum. Comments 6: In all text, please revise that name of plants are in italic  (A. ampeloprasum and  T. violacea). Response 6: Done. Comments 7: Regarding to ”Coefficients of variability (CV) showed a wide range of values in the nutritional parameters. In general, garden garlic flowers had lower coefficients of variability than those shown by the parameters of wild leek flowers.” The authors conducted an interesting study of the flowers of two species of  the liliaceae family to suggest them as edible, but the comparison between the species could indicate a distortion for the interpretation of the results. Response 7: The statistical study was carried out to provide comparative data and to give a positive view of the results. We believe that the data are interesting for the fields of nutrition, gastronomy, and food science, regardless of the differences found between both flowers. Comments 8: I suggest reanalyzing data in each assay, data were expressed as fresh weight material. Since the moisture content varies among the flower samples, the comparative analysis is not valid. If results expressed as dry weight material, then comparisons between the samples of the flowers both species are acceptable. Response 8: We think it is better to keep the data expressed in terms of fresh matter, since this fresh matter represents the reality of the edible fraction of the flowers. The expression in terms of dry matter allows a real comparison of the flowers of the two species, but we insist that this is not the fundamental objective of the work. In any case, we have carried out the statistical study again. The results are shown in the table, and it can be observed that the level of significance changes for four elements. But we continue to think that it is more appropriate to express the data by quantity of edible matter (100 g of fresh weight) which would be the reality of the composition of the edible fraction of the flower.   Parameter Garden garlic flowers Wild leek flowers   Mean ± SD CV (%) Mean ± SD CV (%) p-value Nutritional value (g 100 g−1 dw)           Moisture 82.192 a ± 0.697 0.848 77.317 b ± 0.067 0.087 0.0003 Dry matter 17.808 b ± 0.697 3.913 22.683 a ± 0.067 0.297 0.0003 Ash 6.607 a ± 0.161 2.441 3.056 b ± 0.433 14.181 0.0002 Crude protein 10.915 b ± 0.476 4.366 19.280 a ± 0.703 3.646 0.0001 Fat 1.398 a± 0.170 12.156 1.773 a ± 0.201 11.322 0.0688 Crude fiber 16.237 a± 0.609 3.753 10.058 b± 0.804 7.990 0.0004 Carbohydrates 64.843 a ± 1.263 1.948 65.833 a ± 1.626 2.470 0.4518 Energy value (kcal 100 g−1) 348.084 b ± 1.030 0.296 376.522 a ± 3.298 0.876 0.0001 Bioactive components           Total polyphenols (mg EAG·100 g−1 dw) 1258.400 b ± 8.547 0.679 1850.320 a ± 225.664 12.196 0.0105 Antioxidant activity by DPPH assay (μmol TE·100 g−1 dw) 4333.86 a ± 184.327 4.253 2407.22 b ± 194.04 8.061 0.0002 Macrominerals (mg 100 g−1 dw)           K 330.004 a ± 49.876 15.114 370.815 a ± 22.743 6.133 0.2667 P 327.733 b ± 9.135 2.787 305.904 a ± 5.725 1.871 0.0247 Ca 590.033 a ± 84.538 14.328 305.663 b ± 7.051 2.307 0.0044 Mg 157.246 a ± 23.442 14.908 156.545 a ± 3.424 2.187 0.9616 Na 53.043 a ± 7.042 13.276 25.143 b ± 4.894 19.466 0.0049 Microminerals (mg 100 g−1 dw)           Fe 32.786 a ± 5.731 17.479 3.396 b ± 0.432 12.738 0.0009 Cu 0.773 a ± 0.143 18.531 0.413 b ± 0.024 5.815 0.0127 Zn 1.952 b ± 0.346 17.741 2.895 a ± 0.035 1.226 0.0094 Mn 1.245 a ± 0.208 16.685 0.753 b ± 0.039 5.144 0.0157 B 1.853 a ± 0.319 17.224 1.542 a ± 0.041 2.673 0.1699 Cr 0.061 a ± 0.012 20.651 0.023 b ± 0.006 25.082 0.0096 Mo 0.069 a ± 0.019 27.964 0.011 b ± 0.002 19.735 0.0066 Se 0.0099 - 0.000 - - Heavy metals (mg 100 g−1 dw)           Cd 0.009 b ± 0.001 15.629 0.025 a ± 0.001 6.073 0.0002 Pb 0.215 a ± 0.034 15.704 0.133 a ± 0.018 13.701 0.0208 Hg 0.0030 - 0.000 - -

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Second review

Article

Aromatic and nutritional composition of edible flowers of garden garlic and wild leek

Herein, the authors conducted a studied on the chemical composition and biological properties of flowers of Tulhia violacea Harv. and Allium ampeloprasum L. with the aim of promoting their as foods containing natural bioactive compounds in their flowers, suggesting them new sustainable cultivation alternatives.

COMMENTS

The document “author_response.pdf”, It isn’t the letter, It is the article pdf.

• Abstract
• Authors should include the aim this work.

 

• “The antioxidant activity by DPPH assay”, please change by anti-radicalary

In review 1), Comments 3: 2.4. Data Analysis “Three replicates were used to obtain the mean values for nutritional, total antioxidant activity, total polyphenolic…”

Please note that if only DPPH capture was assayed, this method does not encompass all possible antioxidant activities.  I insist that, To generalize and use total antioxidant activity, is necessary to assay various methods; in this case, the authors can refer to "antiradical activity." Considered that assays applied to determine the antioxidant capacity of complex samples, are based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin–Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test, and the [2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl] (DPPH) test.

The authors only changed the total antioxidant by antioxidant, but this is not correct. The  response “ 3: Done.” does not correspond. Please, if possible, revise and the following article. It is necessary to ensure the correct definition.

Estimation of antiradical properties of antioxidants using DPPH assay: A critical review and results, Krishnanand Mishra, Himanshu Ojha, Nabo Kumar Chaudhury, Food Chemistry, 130, 4, 2012,Pages 1036-1043, https://doi.org/10.1016/j.foodchem.2011.07.127

There are methodological mistakes that the authors are not willing to modified.

The food that are recommend consumption for their nutritional value, metabolites with potential antioxidant properties, the absence heavy metal, to standarization must be expressed as dry weight, so that can be compared other foods, especially in this that makes a comparison the edible flowers of two species different

There are methodological mistakes that authors are not willing to modify. The value of food for consumption (nutritional value metabolites with potential antioxidant properties and the absence of heavy metals), must be standardized and as dry so that can be compared to other foods. This is especially important when comparing edible flowers two different species.

Author Response

The authors appreciate the work and good work of the reviewer. We understand the review criteria and indicate the changes made to complete the observations and improve the quality of the manuscript. We apologize, because at the time of attaching we made a mistake with the document “author_response.pdf” and attached the letter instead of the article.pdf

Comments 1.

Abstract. Authors should include the aim this work.

We have modified the sentence in the abstract so that it now reads: The main objective of this work has been to study the nutritional and aromatic value of garden garlic (Tulbaghia violacea) and wild leek (Allium ampeloprasum) on lines 16-18.

Comments 2. “The antioxidant activity by DPPH assay”, please change by anti-radicalary....

We have followed the reviewer's suggestion and have read and understood the reference indicated. We have acted incorrectly with the antioxidant activity, because that is how we have found it in other references. We thank the reviewer for the opportunity to rectify, and not make the same mistake in future works. The authors are willing to make changes and have changed the expression for antiradical activity by DPPH assay throughout the text.

Comments 3. There are methodological mistakes that authors are not willing to modify. The value of food for consumption (nutritional value metabolites with potential antioxidant properties and the absence of heavy metals), must be standardized and as dry so that can be compared to other foods. This is especially important when comparing edible flowers two different species.

In many articles, when food is referred to as an edible fraction, it is expressed in fresh matter, since it is the total amount consumed. The values that have been compared in the paper have considered this effect of the moisture content of the flowers. But we understand the reviewer's view and we are willing to include the table with the differences that this generates and the texts within the document have also been changed.

Note to the editor: to avoid the complexity that numerical changes in a table entail, the table expressed in fresh matter has been eliminated and replaced by the new table with the data expressed in dry matter.

 

Author Response File: Author Response.pdf