Comparative Life Cycle Assessment (LCA) of Packaging Materials for Tomato-Based Products to Pave the Way for Increasing Tomato Processing Industry Sustainability

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This is an interesting paper that assesses Comparative Life Cycle Assessment of Packaging Materials for Tomato-based products to Pave the Way for Increasing Tomato Processing Industry Sustainability. It is well organized and the results are interesting. While I have few comments for improving readability and emphasizing key results, the manuscript is worth consideration for publication after addressing these comments and revising the manuscript.

1. As feedstock for the experiments, peeled tomatoes in tinplate cans of different weights of 230 gr, 400 gr, 2.5 kg, 3.0 kg, and tomato puree in glass bottles in different weights of 320 gr, 350 gr, 500 gr and 700gr were used to : to evaluate the LCA. One of my initial concerns was whether it would be possible to accurately identify and pinpoint an absence of film-packaging tomato products due its popularity. This will make the motivation for this experiment easier to understand in my opinion and introduce the reader better into the topic.
2. Something else missing from the Introduction is a correlation with papers based on LCA analysis of different continents (Africa, Asia etc).
3. M&M overall. Line 370-373 should be transferred in to the M&M section. And briefly explained.
4. Figure 3The data looks with a very significant influence and domination of packaging over processing. Is it correct?

Based on the above points, I would propose a minorr revision of the manuscript.

 

Author Response

Response to reviewers

Manuscript ID: sustainability-3524600

Title: Comparative LCA of Packaging Materials for Tomato-based Products to Pave the Way for Increasing Tomato Processing Industry Sustainability

The authors would like to thank the editor and all the reviewers for the time and effort spent reviewing our manuscript, and for their useful and effective inputs that helped us to further improve it.

The changes made by the authors, in response to the reviewers’ comments, are reported in the following.

 

Reviewer 1 Comments

This is an interesting paper that assesses Comparative Life Cycle Assessment of Packaging Materials for Tomato-based products to Pave the Way for Increasing Tomato Processing Industry Sustainability. It is well organized and the results are interesting. While I have few comments for improving readability and emphasizing key results, the manuscript is worth consideration for publication after addressing these comments and revising the manuscript.

Based on the above points, I would propose a minor revision of the manuscript.

1. As feedstock for the experiments, peeled tomatoes in tinplate cans of different weights of 230 gr, 400 gr, 2.5 kg, 3.0 kg, and tomato puree in glass bottles in different weights of 320 gr, 350 gr, 500 gr and 700gr were used to : to evaluate the LCA. One of my initial concerns was whether it would be possible to accurately identify and pinpoint an absence of film-packaging tomato products due its popularity. This will make the motivation for this experiment easier to understand in my opinion and introduce the reader better into the topic.

Answer: We thank the Reviewer 1 for the valuable comment. This study focused on the LCA of tin cans and glass bottles as primary packaging materials for tomato products.

Tin cans together with glass packaging (bottles, pots, jars, etc.) were historically used to pack tomato products undergoing in container pasteurization. Moreover, still today they represent the main packaging materials for processing, but are considered invaluable also by retailers of tomato products.

Tomato products such as peeled, chopped, diced, whole, etc., are traditionally packaged in tin can, which holds a market share of about 87% (The tomato news conference, 2024). (https://www.tomatonews.com/en/lighter-and-more-long-lasting-the-challenges-of-packaging_2_206.html)

There is no evidence on the utilization of paper-based packaging, rigid plastics and flexible pouches for these products due to the protective action exerted by the container on the integrity of the tomato fruits and pieces.

The limited adoption of other these type of packaging materials is mainly due to factors related to product shelf life and barrier properties of the packaging material. Metal cans and glass bottles provide superior protection against oxygen, light, and moisture, which are critical factors in preserving quality, taste, and nutritional value of tomato-based products over time. On the other hand, while flexible pouches, often used for intermediate products (pouches of 250-300 kg of tomato puree), offer advantages such as reduced weight and lower transportation costs, they generally have lower barrier performance compared to metal and glass. Despite advancements in multilayer films and high-barrier materials, flexible pouches may still allow higher oxygen and moisture permeability, potentially compromising the stability and safety of tomato products, especially those requiring long-term storage (Marsh et al., 2007).

2. Something else missing from the Introduction is a correlation with papers based on LCA analysis of different continents (Africa, Asia etc).

Answer: We thank the Reviewer1 for the valuable suggestion. However, to the best of our knowledge there are no information available in the literature on LCA studies on tomato processing in Africa. The LCA studies of African researchers focused on the cultivation phase only. While another reference was added in the list of references, cited in the introduction and summarized in in Table 2 regarding the LCA studies on tomato processing carried in Asia.

3. M&M overall. Line 370-373 should be transferred in to the M&M section. And briefly explained.

Answer: The authors would like to thank the reviewer for this recommendation. The sentence has been moved to the material and method section.

4. Figure 3 The data looks with a very significant influence and domination of packaging over processing. Is it correct?

Answer: We thank the reviewer for rising this point. Indeed, based on LCA analysis in both midpoint and endpoint level, packaging materials have the highest effects on the environment and this is the reason why sensitivity analyses were done for the packaging stage.

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

the authors address a much debated topic in a clear manner, defining the assumptions and limitations of the study exhaustively. The topic is to understand what is the most impacting process in the production of Tomato puree and peeled tomatoes, including the cultivation and processing.

Only some questions I would like to address:

1) Please Justify why do you use midpoint indicators (CML-IA) to perform the contribution analysis, then the endpoint indicators for material alternative scenarios, and then return later to midpoint indicators to study the EoL alternative scenarios, it est. the sensitivity analysis to mitigate the environmental impact of the packaging phase in tomato processing ?

2) in the abstract line 16 in the pdf version there is "CML-1A" instead of "CML-IA"

3) Although the authors stated "To understand whether recycling packaging material of current packaging types used in the company (tinplate cans and glass bottles) can compensate for their environmental impacts, the EoL scenarios of these materials have been evaluated by LCA." lines 483-485. In my opinion the authors should explain how the recycling phase has been accounted for, by showing the inventory table of the recycling scenarios (also reported in the supplementary materials). 

 

Author Response

Response to reviewers

Manuscript ID: sustainability-3524600

Title: Comparative LCA of Packaging Materials for Tomato-based Products to Pave the Way for Increasing Tomato Processing Industry Sustainability

The authors would like to thank the editor and all the reviewers for the time and effort spent reviewing our manuscript, and for their useful and effective inputs that helped us to further improve it.

The changes made by the authors, in response to the reviewers’ comments, are reported in the following.

 

Reviewer 2 Comments

 

The authors address a much debated topic in a clear manner, defining the assumptions and limitations of the study exhaustively. The topic is to understand what is the most impacting process in the production of Tomato puree and peeled tomatoes, including the cultivation and processing.

 

Only some questions I would like to address:

 

1. Please Justify why do you use midpoint indicators (CML-IA) to perform the contribution analysis, then the endpoint indicators for material alternative scenarios, and then return later to midpoint indicators to study the EoL alternative scenarios, it est. the sensitivity analysis to mitigate the environmental impact of the packaging phase in tomato processing ?

 

Answer: We thank the Reviewer 2 for the comment. In this study CML-IA baseline has been used as the methodology for considering the environmental impact in midpoint level for all stages (from cradle to grave including agriculture, processing, packaging, and transportation). The evaluation of environmental impact in endpoint level has been presented (from cradle to grave) to show the main hotspots (packaging phase) among all categories. The endpoint evaluation was an extra evaluation which made the results easier for non-experts to interpret. For the other evaluation, including different packaging materials and sensitivity analysis, midpoint evaluation was only considered to compare the impact of the different materials that can be used for packaging (within the main packaging hotspot).

 

2. In the abstract line 16 in the pdf version there is "CML-1A" instead of "CML-IA"

Answer: We thank the Reviewer 2 for the suggestion. The mistake has been corrected.

3. Although the authors stated "To understand whether recycling packaging material of current packaging types used in the company (tinplate cans and glass bottles) can compensate for their environmental impacts, the EoL scenarios of these materials have been evaluated by LCA." lines 483-485. In my opinion the authors should explain how the recycling phase has been accounted for, by showing the inventory table of the recycling scenarios (also reported in the supplementary materials).

Answer: We thank the Reviewer 2 for the valuable suggestion. The recycling of packaging material according to current situation of Italy was considered in the scenarios SA-1: EoL scenario of tinplate packaging (current situation in Italy) and SA-5: EoL scenario of glass packaging (current situation in Italy) with the comprehensive explanation reported in the paragraph 3.4.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This study presents a thorough life cycle analysis of a tomato processing facility that produces a can of peeled tomatoes and a bottle of tomato puree. The authors presented a robust cradle to grave LCA for producing these products using data from a commercial production facility. Current state tin-based packing for peeled tomatoes and glass bottle based packing for tomato puree have the largest contribution in their life cycle production. The inclusion of the end-of-life scenario and sensitivity analysis was very informative. The discussion of major hotspots that include packaging materials along with the details on why those have higher impacts provides valuable information to readers. The authors also presented ways to reduce the environmental impacts of these materials with alternatives. Overall, this study provides clear, descriptive, and valuable information for improving sustainability aspects of the tomato processing industry. I have a few minor concerns.

1. The first two paragraphs in the introduction seem to be very broad and distract readers from the main focus of this study. Therefore, I suggest readers reduce these unnecessary discussions.
2. Although authors have discussed somewhat in the results section, it would be better to provide background information on why current packing materials (tin can and glass bottle) are used for packaging in the introduction part.
3. Energy is one of the major factors in the production of packaging materials. It would be informative to readers if you could also discuss the source of energy used in their production and any possibilities of reducing their impact, such as grid decarbonization.

Author Response

Response to reviewers

Manuscript ID: sustainability-3524600

Title: Comparative LCA of Packaging Materials for Tomato-based Products to Pave the Way for Increasing Tomato Processing Industry Sustainability

The authors would like to thank the editor and all the reviewers for the time and effort spent reviewing our manuscript, and for their useful and effective inputs that helped us to further improve it.

The changes made by the authors, in response to the reviewers’ comments, are reported in the following.

 

Reviewer 3 Comments

 

This study presents a thorough life cycle analysis of a tomato processing facility that produces a can of peeled tomatoes and a bottle of tomato puree. The authors presented a robust cradle to grave LCA for producing these products using data from a commercial production facility. Current state tin-based packing for peeled tomatoes and glass bottle based packing for tomato puree have the largest contribution in their life cycle production. The inclusion of the end-of-life scenario and sensitivity analysis was very informative. The discussion of major hotspots that include packaging materials along with the details on why those have higher impacts provides valuable information to readers. The authors also presented ways to reduce the environmental impacts of these materials with alternatives. Overall, this study provides clear, descriptive, and valuable information for improving sustainability aspects of the tomato processing industry. I have a few minor concerns.

 

1. The first two paragraphs in the introduction seem to be very broad and distract readers from the main focus of this study. Therefore, I suggest readers reduce these unnecessary discussions.

 

Answer: We thank the reviewer 3 for the comment. The unnecessary information have been removed from the introduction.

2. Although authors have discussed somewhat in the results section, it would be better to provide background information on why current packing materials (tin can and glass bottle) are used for packaging in the introduction pa

 

Answer: We thank the Reviewer 3 for the comment.  A paragraph about the reasons of choosing tinplate can and glass bottle for the LCA of packaging materials of tomato products has been added to the Introduction section (Lines 77-95)

 

3. Energy is one of the major factors in the production of packaging materials. It would be informative to readers if you could also discuss the source of energy used in their production and any possibilities of reducing their impact, such as grid decarbonization.

 

Answer: We thank the Reviewer 3 for the recommendation. We do not have access to specific data on the energy consumption involved in the production of packaging materials. Moreover, the primary objective of this study was to identify the main environmental hotspots in the packaging of tomato-based products and explore potential solutions to reduce their environmental impact. This was done by considering different scenarios, involving the use of alternative materials, with a particular emphasis on the importance of recycling.

While it is certainly possible to conduct additional sensitivity analyses related to the energy used in the production process, it falls outside the scope and objectives of this study.

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

In its present form the paper is worth of publication