Effect of Heat–Moisture Treatment on Crystallinity, Digestibility Properties, Bioactive Compounds, and Antioxidant Activity of Purple Rice (Oryza sativa L. indica) Flour

Round 1

Reviewer 1 Report

The goal of the applied and compared HMT methods are only guessed, but not explicitly described.

The presentation of results would be more insightful on plots and bar-charts.

Other comments are in the attached document.

 

Comments for author File: Comments.docx

Author Response

Dear sir, 

Thank you for your useful comments and suggestions. May I answer your comments and suggestions as follows

1. The goal of the applied and compared HMT methods are only guessed, but not explicitly described.

Ans : Thank you for your positive feedback. The goal of this research is to investigate the impact of heat-moisture treatment (HMT) on resistant starch (RS) in purple rice flour by varying the moisture content, temperature, and thermal source (oven and autoclave). The study aims to determine the effect of HMT on the swelling power, solubility, resistant starch content, and antioxidant activity of the flour. Heat-moisture treatment is an effective method to modify the properties of flour, making it more functional and nutritious. The results of this research can provide valuable insights to the food industry for developing healthier food products.

 

2. The presentation of results would be more insightful on plots and bar-charts.

Ans : Thank you for your comment. I have added bar charts to show the results of swelling capacity, solubility, and bioactive compounds (such as total phenolic compound and total anthocyanin content). These charts will make the presentation of my results more insightful and visually appealing.

 

3. Other comments are in the attached document.

Ans : I have made revisions according to all the valuable comments provided in the attached document. However, there is an issue with the version of MS Word in the attached document, which may cause formatting errors and confusion.

Again, thank you for your comments and suggestions and I hope those answers are exactly what you asked. 

Best regards,

Nopakarn Chandet, Ph.D.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript looks like a report. Novel research is not incorporated. The outcome is quite expected. It is obvious that the antioxidant property will decrease when the temperature goes beyond 80°C . The challenges are not defined properly which the authors tried to solve. Some application needs to be incorporated into the paper for quality betterment.

1.       Provide some examples of Resistant starch

2.       Line 113; replace blender with grinder

3.       Equations should be numbered

4.       Conclusion is just a repetition of the results found.

 

5.       The principal mechanisms of the oven and autoclave are different. The effect of pressure was not observed but a cumulative one. Why is that?

Author Response

Dear sir, 

Thank you for your useful comments and suggestions. May I answer your comments and suggestions as follow:

The manuscript looks like a report. Novel research is not incorporated. The outcome is quite expected. It is obvious that the antioxidant property will decrease when the temperature goes beyond 80°C . The challenges are not defined properly which the authors tried to solve. Some application needs to be incorporated into the paper for quality betterment.

Ans : To address the concerns raised in the comment, we have revised the manuscript to better highlight the novelty of our research and define the challenges we sought to address. In conclusion, we have included more detailed information on potential applications of our findings in the food industry. Additionally, we will make it clear that while the effect of temperature on antioxidant activity is known, our study focused specifically on the impact of HMT on resistant starch and other properties of purple rice flour. We believe these revisions will enhance the quality and significance of our research.

 

1. Provide some examples of Resistant starch

Ans : I have provided some examples of resistant starch in the introduction, on line 56.

 

2. Line 113; replace blender with grinder

Ans : I have replaced the blender with a grinder.

 

3. Equations should be numbered

Ans : I have inserted numbers in the sequence of equations.

 

4. Conclusion is just a repetition of the results found.

Ans : I have rewritten the conclusion to add highlights and increase the interest in the research, as well as to suggest the potential development of modified purple rice flour for future food industry use. Specifically, the potential and practical usefulness of this approach will be emphasized.

 

5. The principal mechanisms of the oven and autoclave are different. The effect of pressure was not observed but a cumulative one. Why is that?

Ans : The principal mechanisms of the oven heat-moisture treatment (OHMT) and autoclave heat-moisture treatment (AHMT) differ in their approach to producing resistant starch. Despite the use of pressure in the AHMT, the effect on RS production is not due to the pressure itself, but rather the cumulative effect of heat and moisture. The pressure merely enhances the transfer of heat and moisture to the starch, leading to greater RS production.

Again, thank you for your comments and suggestions and I hope those answers are exactly what you asked. 

Best regards,

Nopakarn Chandet, Ph.D.

 

Reviewer 3 Report

The manuscript reports on heat and moisture treatment of purple rice flour and its effects on main components and texture, as well as antioxidant activity. In the area of my expertise, the methods for total phenolic and total anthocyanin content determination and the DPPH antioxidant assay used are appropriate and reasonable. Observation of reduction in these components after heat and moisture treatment is in agreement with existing understanding of the property of phenolics, including anthocyanins. A couple of minor edits below can be looked at.

Line 107: were employed for to investigate the determination off proximate

Line 192: in the equation, D should be e. 

Author Response

Dear sir, 

Thank you for your useful comments and suggestions. May I answer your comments and suggestions as follow:

The manuscript reports on heat and moisture treatment of purple rice flour and its effects on main components and texture, as well as antioxidant activity. In the area of my expertise, the methods for total phenolic and total anthocyanin content determination and the DPPH antioxidant assay used are appropriate and reasonable. Observation of reduction in these components after heat and moisture treatment is in agreement with existing understanding of the property of phenolics, including anthocyanins. A couple of minor edits below can be looked at.

Line 107: were employed for to investigate the determination off proximate

Line 192: in the equation, D should be e. 

Ans : I appreciate being able to review and provide feedback on my manuscript reports. I agree with you that the methods used for determining the total phenolic and total anthocyanin content, as well as the DPPH antioxidant activity, are appropriate and reasonable based on my understanding of these techniques. Additionally, I have revised the minor edits you mentioned at lines 107 and 192 for clarity and accuracy as much as possible.

Again, thank you for your comments and suggestions and I hope those answers are exactly what you asked. 

Best regards,

Nopakarn Chandet, Ph.D.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Significant improvements were done.

In 2.5 steaming method was supplemented with "in a water bath". However Reviewer is not convenienced, that 90°C in an atmospheric water bath is a steaming treatment, since it is below the boiling point of water into steam, and is without any preassure. Steam tables start above 100°C.

GOD POD assay kit is still not specified (manufacturer, measuring range etc.)

Caption of Figure 3 are far away from the Figure.

Some minor trends in results were not evaluated, like crystalinity AHMT2(20) which were the opposite then general trends.

 

 

Comments for author File: Comments.pdf

Author Response

Dear sir, 

I would like to take this opportunity to express my gratitude for taking the time to review my manuscript. Your insightful comments, suggestions, and feedback have been invaluable to me.Your expertise in the field has allowed me to improve my work. The answers for your comments and suggestion were presented below.

1. Significant improvements were done.

Ans. Thank you very much for your comments and suggestions. Your comment was extremely valuable in helping me to revise the manuscript and improve the research's value.

 

2. In 2.5 steaming method was supplemented with "in a water bath". However Reviewer is not convenience, that 90°C in an atmospheric water bath is a steaming treatment, since it is below the boiling point of water into steam, and is without any pressure. Steam tables start above 100°C.

Ans. Thank you very much for adding "in a water bath," as suggested in your comment regarding the concept of "stream." I have now replaced the word "streamed" with "soaked" in section 2.5 of the manuscript.

 

3. GOD POD assay kit is still not specified (manufacturer, measuring range etc.)

Ans. I have changed the writing format for accuracy and internationalization from "glucose oxidase (GOD) and peroxidase (POD) assay kit" to "D-glucose assay kit (GOPOD)" assay kit purchased from Megazyme, Ireland with a measuring range of 4 to 100 μg of glucose per assay. I have added this information to line 170 as per your suggestion in the attached document.

 

4. Caption of Figure 3 are far away from the Figure.

Ans. I have made the revisions according to your suggestions.

 

5. Some minor trends in results were not evaluated, like crystalinity AHMT2(20) which were the opposite then general trends.

Ans. Thank you for your suggestion. I have added more information regarding the effects of pressure and moisture content in purple rice flour, including the differences that affect crystallinity. Experimental results show that high levels of moisture, around 25 and 30%, have a significant impact on reducing crystallinity. This is explained in detail in line 393. Furthermore, I have made other corrections as suggested in the attached file.

Thank you again for your contributions to the field.

Sincerely,

Nopakarn Chandet

 

Reviewer 2 Report

The authors did thorough corrections to the paper and uplifted the quality. However, minor spelling and grammar check is needed before final publication. 

Author Response

Dear sir,

We would like to take this opportunity to express our gratitude for taking the time to review our manuscript. Your insightful comments, suggestions, and feedback have been invaluable to us. Your expertise in the field has allowed us to improve our work. With this revision version, we made sure to conduct a final spelling and grammar check before publication to ensure the highest possible quality. Thank you again for your contributions to the field.

Sincerely,

Nopakarn Chandet