Impact of Vegetal Protein on the Physicochemical and Microstructural Properties of Microencapsulated Mexican Red Pitaya (Stenocereus thurberi) Juice

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

This study investigated plant-based proteins (pea, rice, bean and whey) as sustainable alternatives for microencapsulating Mexican red pitaya juice via spray drying, aiming to preserve bioactive compounds and improve stability. While the study is well-structured and provides valuable insights, there are a few questions and remarks that Authors should address:

• The acid hydrolysis step for plant proteins (Section 2.4) is not justified. Hydrolysis can alter protein functionality, and its necessity for encapsulation efficacy is unclear.
• Protein content analysis (AOAC 920.152) likely uses a default nitrogen conversion factor of 6.25, which may overestimate plant protein content due to variations in amino acid profiles. Adjustments for specific proteins (e.g., 5.7 for wheat) would improve accuracy.
• The Folin-Ciocalteu method measures reducing substances, not just phenolics, leading to potential overestimation. Additionally, bound phenolics in plant proteins may not be fully extracted with methanol:water, underestimating TPC.
• SEM reveals large particle sizes for BP (26.5 µm) and RP (35.73 µm) compared to PP (5.79 µm) and WP (4.70 µm). The impact of particle size on dissolution, stability, and bioavailability is not properly discussed, limiting practical insights.

Some minor corrections:

• Inconsistent terminology ("Tepary protein" vs. "bean protein") require correction. Ensure all abbreviations are consistent throughout the paper. Also, The term "vegetable proteins" is used interchangeably with "plant proteins”. I recommend to use “plant-based proteins".
• Line 149-151 – Please rewrite, connecting AOAC reference numbers to the analysis.
• Line 199 – Correct to "Soto-Dagnino et al. (2024)”.
• Line 295 -"encapsulados a base de proteínas" - Translate to "protein-based encapsulates."
• Line 392 – Did you meant to use the word wedges? Not encapsulates?
• Line 460 - the text refers to "Figure 1a." Is it Figure 3a instead?
• In Table 1, all treatments share the same superscript for moisture content (e.g., "a"), suggesting no significant differences, but standard deviations are small. Please review.

 

Author Response

Reviewer 1

Dear Authors,

This study investigated plant-based proteins (pea, rice, bean and whey) as sustainable alternatives for microencapsulating Mexican red pitaya juice via spray drying, aiming to preserve bioactive compounds and improve stability. While the study is well-structured and provides valuable insights, there are a few questions and remarks that Authors should address:

Dear Reviewer 1

We appreciate the comments and observations made to the manuscript appliedchem-3618788, the changes and marked observations were incorporated. All changes made are marked in red into the text.

Reviewer 1

The acid hydrolysis step for plant proteins (Section 2.4) is not justified. Hydrolysis can alter protein functionality, and its necessity for encapsulation efficacy is unclear.

 

Authors

Thank you for your observation. A sentence was added in materials and methods section 2.4 to explain the impact of acid hydrolysis (Page 3, lines 128-130 and Page 4, lines 137-138)

Reviewer 1

Protein content analysis (AOAC 920.152) likely uses a default nitrogen conversion factor of 6.25, which may overestimate plant protein content due to variations in amino acid profiles. Adjustments for specific proteins (e.g., 5.7 for wheat) would improve accuracy.

 

Authors

Thank you for the comment. The protein analysis was corrected to take into account the protein factor for each material (Table 1). A supporting reference was added to the text (Page 4, lines151-155)

Reviewer 1

The Folin-Ciocalteu method measures reducing substances, not just phenolics, leading to potential overestimation. Additionally, bound phenolics in plant proteins may not be fully extracted with methanol:water, underestimating TPC.

Authors

I agree with your comment. A statement was added describing the procedure to avoid overestimations of TPC. Results (Table 2) and the Materials and Methods section 2.11.1 and 2.11.2 (Page 5, lines 182-183 and lines 193-195) were modified

Reviewer 1

SEM reveals large particle sizes for BP (26.5 µm) and RP (35.73 µm) compared to PP (5.79 µm) and WP (4.70 µm). The impact of particle size on dissolution, stability, and bioavailability is not properly discussed, limiting practical insights.

 

Authors

Thanks for your observation. A paragraph has been added to discuss joint size in stability and its practical implications (Page 12, lines 503-513)

Reviewer 1

Some minor corrections:

Inconsistent terminology ("Tepary protein" vs. "bean protein") require correction. Ensure all abbreviations are consistent throughout the paper. Also, The term "vegetable proteins" is used interchangeably with "plant proteins”. I recommend to use “plant-based proteins".

Authors

Your observation was attended. (Page 8, line 319).

Reviewer 1

Line 149-151 – Please rewrite, connecting AOAC reference numbers to the analysis.

Authors

Thanks for your observation. The proximal characterization section was modified for better understanding (Page 4, line 151-153)

Reviewer 1

Line 199 – Correct to "Soto-Dagnino et al. (2024)”.

Authors

Your observation was attended. (Page 5, line 181).

 

Reviewer 1

Line 295 -"encapsulados a base de proteínas" - Translate to "protein-based encapsulates."

Authors

Your observations were attended. (Page 7, line 275)

Reviewer 1

Line 392 – Did you meant to use the word wedges? Not encapsulates?

Authors

Thank, the word was changed (Page 10, line 412)

 

Reviewer 1

Line 460 - the text refers to "Figure 1a." Is it Figure 3a instead?

Authors

Your observations were attended. (Page 11, line 478)

 

Reviewer 1

In Table 1, all treatments share the same superscript for moisture content (e.g., "a"), suggesting no significant differences, but standard deviations are small. Please review.

 

Authors

Sorry. Your observation was attended and Table 1 and results section was modified (Page 7, line 273-275).

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Comments to Author

Manuscript Number: Appliedchem-3618788

 

The manuscript titled “Impact of vegetal protein on the physicochemical and micro-structural

properties of microencapsulated Mexican red pitaya (Stenocereus thurberi) juice” evaluates the effects of various carrier agents, such as plant proteins and maltodextrin, on the encapsulation of Mexican red pitaya juice by spray drying. The study finds that plant proteins can improve product properties, such as betalain retention and protein content. However, the research has limitations. It lacks in-depth exploration of sensory qualities and long-term stability. In addition, the interaction mechanisms between the carriers and pitaya components are not fully elucidated. Moreover, the interpretation of the results is unconvincing, and some format and content need to be revised. Some of the major points to be answered are listed below.

 

1. Paragraph 2.4,Regarding the protein hydrolysis method, it is not clear why only PP, RP, and BP were hydrolyzed while WP was not. I suggest providing a clear explanation for this difference in treatment to ensure the scientificity and consistency of the experimental design.
2. Paragraph 3.5.1,when discussing the total betalain content, the comparison of betalain retention among different treatments is somewhat confusing. The authors should clearly state the reasons for the differences in retention more systematically, for example, by comparing the chemical structures of the carrier agents and their interactions with betalains.
3. Table 1, “TP” is used instead of “BP”(bean protein) in some places.Please confirm whether there is consistency throughout the paper.
4. When comparing the values of bioactive compounds in red pitaya juice with previous studies, the authors simply attribute the differences to the age of the pitaya fruits, fruit maturity, or extraction method. This analysis is too simplistic. I suggest that more in-depth research should be conducted, and more evidence-based explanations, such as statistical analysis of the possible factors, should be provided.
5. In the “Keywords” section, the terms should be separated by semicolons,please revise it carefully.
6. Paragraph 3.5.1, when comparing the bioactive compound values of red pitaya juice with previous studies, the authors simply attribute the differences to the age of the pitaya fruits, fruit maturity, or extraction method. This analysis is too simplistic. Please conduct more in-depth research and provide more evidence-based explanations, such as statistical analysis of the possible factors.

Author Response

Reviewer 2

The manuscript titled “Impact of vegetal protein on the physicochemical and micro-structura  properties of microencapsulated Mexican red pitaya (Stenocereus thurberi) juice” evaluates the effects of various carrier agents, such as plant proteins and maltodextrin, on the encapsulation of Mexican red pitaya juice by spray drying. The study finds that plant proteins can improve product properties, such as betalain retention and protein content. However, the research has limitations. It lacks in-depth exploration of sensory qualities and long-term stability. In addition, the interaction mechanisms between the carriers and pitaya components are not fully elucidated. Moreover, the interpretation of the results is unconvincing, and some format and content need to be revised. Some of the major points to be answered are listed below.

Dear Reviewer 2

We appreciate the comments and observations made to the manuscript appliedchem-3618788, the changes and marked observations were incorporated. All changes made are marked in red into the text.

Reviewer 2

Paragraph 2.4, Regarding the protein hydrolysis method, it is not clear why only PP, RP, and BP were hydrolyzed while WP was not. I suggest providing a clear explanation for this difference in treatment to ensure the scientificity and consistency of the experimental design.

Authors

Thanks for your feedback. A statement was added to clarify the hydrolysis of the materials evaluated as wall material (Page 3, lines 128-130 and page 4, lines 137-138).

 Reviewer 2

Paragraph 3.5.1, when discussing the total betalain content, the comparison of betalain retention among different treatments is somewhat confusing. The authors should clearly state the reasons for the differences in retention more systematically, for example, by comparing the chemical structures of the carrier agents and their interactions with betalains.

Authors

Your observations were attended. A paragraph was added for better understanding of the interactions of betalains and proteins used as wall material (Page 10, lines 395-399, and lines 408-415)

Reviewer 2

Table 1, “TP” is used instead of “BP” (bean protein) in some places. Please confirm whether there is consistency throughout the paper.

Authors

Sorry. The term has been changed: Table 1, Table 2, Table 3, Table 4 and Figure 1

Reviewer 2

When comparing the values of bioactive compounds in red pitaya juice with previous studies, the authors simply attribute the differences to the age of the pitaya fruits, fruit maturity, or extraction method. This analysis is too simplistic. I suggest that more in-depth research should be conducted, and more evidence-based explanations, such as statistical analysis of the possible factors, should be provided.

Author

Your observations were attended. A paragraph is included for a better understanding of the changes (Page 7, lines 252-266)

Reviewer 2

In the “Keywords” section, the terms should be separated by semicolons, please revise it carefully.

Authors

Your observations were attended. (Page 1)

Reviewer 2

Paragraph 3.5.1, when comparing the bioactive compound values of red pitaya juice with previous studies, the authors simply attribute the differences to the age of the pitaya fruits, fruit maturity, or extraction method. This analysis is too simplistic. Please conduct more in-depth research and provide more evidence-based explanations, such as statistical analysis of the possible factors.

Your observations were attended. A paragraph is included for a better understanding of the changes (Page 7, lines 252-266)

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors addressed my comments. 

Reviewer 2 Report

Comments and Suggestions for Authors

Agree to publish.