Current Challenges in the Sustainable Valorisation of Agri-Food Wastes: A Review

Round 1

Reviewer 1 Report

The manuscript entitled “Current challenges in the sustainable valorisation of agri-food wastes. A review” is a very interesting, timely and informative review. In this work, some of the crucial sustainable challenges with an impact on the valorisation of the agri-food sector losses/waste and by-products are discussed and identified, as well as several opportunities unity, trends and innovations. Potential applications and uses of the most important compounds found in food losses/waste will be highlighted with particular attention to the food industry, pharmaceutical industry and the environment. This review has the potential of becoming an important scientific contribution. The manuscript has a good potential of being published, however some corrections should be made.

All chapters are described exhaustively and are accompanied by a careful and punctual bibliographic research. Only paragraph 2 "Extraction techniques for bioactive recovery from agri-food wastes" should be revised. Indeed, lines 75-76 introduce the currently most widely used green extraction methods. However, some of them have been neglected that have had considerable interest in recent years. These methods (e.g. Microwave-assisted extraction, Enzyme-assisted extraction and Pressurized liquid extraction) should be added and described in your work. It is advisable to consult and critically describe the following articles:

-          Elik, A., Yanık, D. K., & Göğüş, F. (2020). Microwave-assisted extraction of carotenoids from carrot juice processing waste using flaxseed oil as a solvent. LWT, 123, 109100.

-          Nadar, S. S., Rao, P., & Rathod, V. K. (2018). Enzyme assisted extraction of biomolecules as an approach to novel extraction technology: A review. Food Research International, 108, 309-330.

-          Lombardelli, C., Liburdi, K., Benucci, I., & Esti, M. (2020). Tailored and synergistic enzyme-assisted extraction of carotenoid-containing chromoplasts from tomatoes. Food and Bioproducts Processing, 121, 43–53

Author Response

Reviewer’s 1 comments: 

«The manuscript entitled “Current challenges in the sustainable valorisation of agri-food wastes. A review” is a very interesting, timely and informative review. In this work, some of the crucial sustainable challenges with an impact on the valorisation of the agri-food sector losses/waste and by-products are discussed and identified, as well as several opportunities unity, trends and innovations. Potential applications and uses of the most important compounds found in food losses/waste will be highlighted with particular attention to the food industry, pharmaceutical industry and the environment. This review has the potential of becoming an important scientific contribution. The manuscript has a good potential of being published, however some corrections should be made.

All chapters are described exhaustively and are accompanied by a careful and punctual bibliographic research. Only paragraph 2 "Extraction techniques for bioactive recovery from agri-food wastes" should be revised. Indeed, lines 75-76 introduce the currently most widely used green extraction methods. However, some of them have been neglected that have had considerable interest in recent years. These methods (e.g. Microwave-assisted extraction, Enzyme-assisted extraction and Pressurized liquid extraction) should be added and described in your work. It is advisable to consult and critically describe the following articles:

-          Elik, A., Yanık, D. K., & Göğüş, F. (2020). Microwave-assisted extraction of carotenoids from carrot juice processing waste using flaxseed oil as a solvent. LWT, 123, 109100.

-          Nadar, S. S., Rao, P., & Rathod, V. K. (2018). Enzyme assisted extraction of biomolecules as an approach to novel extraction technology: A review. Food Research International, 108, 309-330.

-          Lombardelli, C., Liburdi, K., Benucci, I., & Esti, M. (2020). Tailored and synergistic enzyme-assisted extraction of carotenoid-containing chromoplasts from tomatoes. Food and Bioproducts Processing, 121, 43–53.»

Authors answer:

The authors thank the reviewer’s comments. New sections concerning microwave-assisted extraction (section 2.5.), enzyme-assisted extraction (section 2.6.), and pressurized liquid extraction (section 2.7.), were added to the manuscript as well as the discussion of articles comprising these extraction techniques (Table 1). A discussion about the combination of ultrasound, microwave, and enzyme-assisted extractions was also added to the manuscript (section 2.5.).

Reviewer 2 Report

Comments and Suggestions for Authors

This article supposes to summarize new alternatives that offered sustainable valorization of agri-food wastes, however, it focuses more on bioactive extraction techniques than other sustainable aspects. It also lacks some important modern extraction techniques such as microwave-assisted extraction, high hydrostatic pressure extraction, ultrasound-assisted enzymatic extraction, and so on. 

Due to all this, the article can be acceptable, although some corrections should be considered:

Comments to the Author:

The manuscript's title is appropriate.
Abstract: The Background of the abstract is well-written. The main procedure and findings of the study are well expressed.
Introduction: A brief survey of existing literature, the purpose and importance is well mentioned. However, the novelty or innovation of the research could be challenged because there are several reviews on this topic already. 

https://doi.org/10.1111/ijfs.15267

https://doi.org/10.1016/j.fbp.2016.06.020 

https://link.springer.com/chapter/10.1007/978-3-030-92415-7_18

https://pubs.acs.org/doi/abs/10.1021/acs.jafc.2c02655

https://link.springer.com/article/10.1007/s11947-017-1961-9

https://www.sciencedirect.com/science/article/pii/S0924224422003661#sec4 

I wonder how the authors could defend the novelty of this article. 

The tables and figures should be improved according to the suggestions. 

Body text: The manuscript lacks critical depth and vast coverage. Many statements made in the review are not supported by references. When works are cited there is little discussion or details provided. So, the reader is in search of originality, newer and updated information in a review but not only listing the already existing knowledge within a very limited scope. In my opinion, in review papers, Authors should deeply discuss all current literature, whereas they selected a few of the most important papers in their opinion.

Conclusion: Should be improved. Restate your major findings and contribution of your study to the existing literature. 

See the attached file for minor concerns. 

Comments for author File: Comments.pdf

Author Response

«Comments and Suggestions for Authors

This article supposes to summarize new alternatives that offered sustainable valorization of agri-food wastes, however, it focuses more on bioactive extraction techniques than other sustainable aspects. It also lacks some important modern extraction techniques such as microwave-assisted extraction, high hydrostatic pressure extraction, ultrasound-assisted enzymatic extraction, and so on. 

Due to all this, the article can be acceptable, although some corrections should be considered:

 

Comments to the Author:

The manuscript's title is appropriate.

Abstract: The Background of the abstract is well-written. The main procedure and findings of the study are well expressed.

Introduction: A brief survey of existing literature, the purpose and importance is well mentioned. However, the novelty or innovation of the research could be challenged because there are several reviews on this topic already. 

https://doi.org/10.1111/ijfs.15267

https://doi.org/10.1016/j.fbp.2016.06.020 

https://link.springer.com/chapter/10.1007/978-3-030-92415-7_18

https://pubs.acs.org/doi/abs/10.1021/acs.jafc.2c02655

https://link.springer.com/article/10.1007/s11947-017-1961-9

https://www.sciencedirect.com/science/article/pii/S0924224422003661#sec4 

I wonder how the authors could defend the novelty of this article. 

 

The tables and figures should be improved according to the suggestions. 

Body text: The manuscript lacks critical depth and vast coverage. Many statements made in the review are not supported by references. When works are cited there is little discussion or details provided. So, the reader is in search of originality, newer and updated information in a review but not only listing the already existing knowledge within a very limited scope. In my opinion, in review papers, Authors should deeply discuss all current literature, whereas they selected a few of the most important papers in their opinion.

Conclusion: Should be improved. Restate your major findings and contribution of your study to the existing literature. 

See the attached file for minor concerns.» 

 

Authors answer:

The authors thank the reviewer’s comments. New sections concerning microwave-assisted extraction (section 2.5.), enzyme-assisted extraction (section 2.6.), and pressurized liquid extraction (section 2.7.), were added to the manuscript as well as the discussion of articles comprising these extraction techniques (Table 1). A discussion about the combination of ultrasound, microwave, and enzyme-assisted extractions was also added to the manuscript (section 2.5.).

The authors considered suggestions made by reviewers in the attached file and act accordingly. The tables and figures were improved and corrected according to the suggestions. The conclusions were also revised and improved. We think the review was considerably improved following all these revisions.

 

Reviewer 3 Report

The review presents important information on current challenges in the sustainable valorisation of agri-food wastes. It is suggested to add information for the improvement of some sections of the manuscript before publication.

 

Page 12

In section 3.3.1. Please mention in a general way the mechanisms used by phenolic compounds to provide antioxidant activity. It can be as hydrogen donors, metal chelators, etc.  

 

Page 12-Page 13

In sections 3.3.1. and 3.3.2. Please also mention in a general way the mechanisms used by bioactive peptides to provide antioxidant activity.

 

Page 13

In section 3.3.3. Please mention that carotenoids are divided into carotenoids and xanthophylls, and some carotenoids such as alpha carotene, beta carotene, and xanthophylls such as beta cryptoxanthin are converted to vitamin A. Vitamin A is one of the main dietary deficiencies worldwide in children. These compounds may have antioxidant activity and their consumption can prevent different diseases in humans, mainly eye diseases.

 

Page 13

In section 3.3.4. It can be mentioned in a general way that dietary fiber is divided into insoluble and soluble. The importance of insoluble fiber can be described, and that the consumption of soluble fiber can reduce the risk of suffering chronic generative diseases, such as diabetes, reduce cholesterol, etc.

Comments for author File: Comments.pdf

Author Response

Reviewer’s 3 comments: 

«The review presents important information on current challenges in the sustainable valorisation of agri-food wastes. It is suggested to add information for the improvement of some sections of the manuscript before publication.

 

Page 12

In section 3.3.1. Please mention in a general way the mechanisms used by phenolic compounds to provide antioxidant activity. It can be as hydrogen donors, metal chelators, etc. 

 

Page 12-Page 13

In sections 3.3.1. and 3.3.2. Please also mention in a general way the mechanisms used by bioactive peptides to provide antioxidant activity.

 

Page 13

In section 3.3.3. Please mention that carotenoids are divided into carotenoids and xanthophylls, and some carotenoids such as alpha carotene, beta carotene, and xanthophylls such as beta cryptoxanthin are converted to vitamin A. Vitamin A is one of the main dietary deficiencies worldwide in children. These compounds may have antioxidant activity and their consumption can prevent different diseases in humans, mainly eye diseases.

 

Page 13

In section 3.3.4. It can be mentioned in a general way that dietary fiber is divided into insoluble and soluble. The importance of insoluble fiber can be described, and that the consumption of soluble fiber can reduce the risk of suffering chronic generative diseases, such as diabetes, reduce cholesterol, etc.»

 

Authors answer:

The authors thank the reviewer’s comments. The mechanisms used by phenolic compounds and bioactive peptides to provide antioxidant activity were added in section 3.3.1. and section 3.3.2, respectively. A discussion about the classification of carotenoids and their health effects was added in section 3.3.3. The importance of soluble and insoluble fibres was described as well as their benefits to human health in section 3.3.4.

Round 2

Reviewer 1 Report

The authors did a great job of editing.