Capsicum chinense Polyphenols Extraction by Supercritical Fluids Using Response Surface Methodology (RSM)

Round 1

Reviewer 1 Report

The comment for the authors:

1. The authors could also determine the content of capsaicin as the most dominant compound in Habanero pepper in addition to phenols in order to make the analysis more complete.

2. The temperature of 65oC used for drying seems to be high considering that phenol degradation can occur at higher temperatures.

3. How the authors chose a concentration of 20% of ethanol? Have the authors previously optimized this parameter?

4. On the basis of which the selection of determined phenolic compounds was made?

5. The authors should have done the screening of polyphenolic profile of Habanero pepper in order to make the analysis more complete and to give an overview of the present phenols in the sample.

6. The authors should revise the text for grammatical and spelling errors.

Author Response

"Please see the attachment."

Author Response File: Author Response.pdf

Reviewer 2 Report

Abstract:

Overall, the abstract provides a comprehensive overview of the study's objectives, methodology, and findings. One suggestion for improvement would be to include specific numerical values for the optimized concentrations of the individual polyphenols, similar to the total polyphenol content mentioned. This addition would further highlight the significance of the results.

Introduction

Break down the introduction into separate paragraphs: The introduction appears as a single long paragraph. It would be helpful to break it down into shorter paragraphs, each addressing a specific point or concept. This would enhance readability and make it easier for readers to follow the flow of information.

Provide a clear objective statement: While the objective of the study is mentioned towards the end of the introduction, it would be beneficial to provide a concise and explicit objective statement at the beginning. This statement should clearly state the aim of the research, such as "The objective of this study is to optimize the conditions of supercritical fluid extraction using response surface methodology to obtain a habanero pepper (Capsicum chinense) extract with the highest concentration of phenolic compounds."

Define abbreviations upon first use: Several abbreviations are used throughout the introduction, such as HP, TPC, RSM, GAE, and Et. It is important to define these abbreviations upon their first use to ensure clarity and avoid confusion for readers.

Provide more context on the significance of phenolic compounds: While the introduction mentions that phenolic compounds have diverse bioactive properties, it would be helpful to provide some examples or further elaboration on the potential applications of these compounds in the fields of food, cosmetics, and pharmaceuticals. This would strengthen the justification for studying and optimizing the extraction of phenolic compounds from habanero peppers.

Expand on the advantages of supercritical fluid extraction: The introduction briefly mentions the advantages of supercritical fluid extraction as a green technology, but it would be beneficial to provide more details on why this method is considered environmentally sustainable and how it compares to other extraction techniques. This would help readers understand the rationale behind choosing this extraction method for the study.

Clarify the research gap: The introduction states that there is a lack of information on the optimization of extraction conditions for total polyphenol content (TPC) and individual phenolic compounds from habanero peppers. However, it would be useful to explain why this gap exists and highlight the specific contribution that this study aims to make in addressing this gap. This would help readers understand the novelty and relevance of the research.

Consider rephrasing complex sentences: Some sentences in the introduction are lengthy and contain multiple ideas or concepts. Breaking them down into shorter sentences or rephrasing them for clarity would improve the readability of the text.

Check for consistent citation style: The introduction includes a few references, but the citation style should be consistent throughout. Ensure that all citations follow a specific format (e.g., APA, MLA) and include all the necessary information, such as authors, year, title, and journal/book details.

 In the Materials and Methods section, the authors mentioned that a wavelength of 280 nm was selected for detection. However, I would like to raise a question regarding this choice, as the commonly used wavelengths for detecting flavonoids are 320 nm or 370 nm. Since the extract contained flavonoids, it would be beneficial for the authors to provide a more detailed explanation of the wavelength selection.

Discussion:

Organize the information in a structured manner, presenting the findings for each phenolic compound separately.

Provide clear headings or subheadings for each compound to facilitate understanding and navigation.

Include a summary or overview at the beginning of the discussion to give an overview of the main findings and their significance.

Use bullet points or numbered lists to highlight key points or factors that influenced the extraction conditions and concentrations of phenolic compounds.

Clearly state the optimal conditions (temperature, pressure, and extraction time) for each phenolic compound, emphasizing the differences compared to previous studies.

Discuss the implications of using ethanol as a co-solvent and its effect on extraction efficiency, pressure requirements, and production costs.

Highlight the importance of temperature and pressure interactions in optimizing extraction conditions for individual phenolic compounds.

Provide explanations for the observed variations in optimal conditions for different phenolic compounds, taking into account factors such as extraction method (static vs. dynamic mode), co-solvent density, and the nature of the compound.

Mention the bioactive properties and potential therapeutic benefits of each phenolic compound extracted from habanero pepper.

Suggest future directions or potential applications, such as microencapsulation techniques, to preserve the bioactive characteristics of the phenolic-rich extract.

By incorporating these improvements, the discussion of the results presented in the study will become clearer and more organized, allowing readers to better understand the findings and their implications.

 Conclusion:

 

Overall, the conclusion accurately reflects the presented information and highlights the significance of the findings in terms of the extraction process, phenolic compound concentration, and potential applications.

Minor editing of English language required

Author Response

 "Please see the attachment."

Author Response File: Author Response.pdf