Review Reports

Round 1

Reviewer 1 Report

An experimental article titled "Xylitol Production from Pineapple Cores (Ananas comosus (L.) Merr) By Enzymatic and Acid Hydrolysis Using Microorganisms Debaryomyces hansenii and Candida tropicalis" corresponds to the "Fermentation" edition, as the authors present the results briefly but in detail research on the production of xylitol from a country-specific raw material - Pineapple Cores, while the process of obtaining the target product is based on fermentation. The authors found that the highest yield of xylitol was obtained after enzymatic hydrolysis, and not acid hydrolysis of raw materials. Commercial enzymes and yeast were used in the work, allowing to reproduce the results described in the article. The strength of the article is the clarity of the presentation of the results obtained and the authors' clear understanding of how they reached reliable conclusions. But the article needs improvement, so the specific comments are outlined below:
Comments:
1. In the annotation, the word "critical" should be replaced with "key". Usually, in the processing of lignocellulosic raw materials, the key step is the pre-treatment of the raw materials. In the case of Pineapple Cores, this is apparently not necessary.
2. In the annotation, the method for determining the component composition of raw materials can be excluded, but it is necessary to include one sentence with a statement of the novelty of the results obtained.
3. In the introduction, it is necessary to list the common raw material sources for xylitol and very briefly outline the technologies for obtaining xylitol from them. Then it will be more clear why the production of xylitol from Indonesia-specific raw materials can be considered as a new technology for the world community.
4. In section “2.6. Analysis method" does not specify a method for determining lignin.
5. I recommend that the authors exclude the designation of components in the fig. 2 photos at a scale of 50 microns, but in the text it is possible to describe the fibers observed by the authors in words.

Author Response

First of all, thank the reviewers who have taken the time to review our manuscript and provide reviews to improve the quality of the manuscript. The following are our answers to questions asked by reviewers.

An experimental article titled "Xylitol Production from Pineapple Cores (Ananas comosus (L.) Merr) By Enzymatic and Acid Hydrolysis Using Microorganisms Debaryomyces hansenii and Candida tropicalis" corresponds to the "Fermentation" edition, as the authors present the results briefly but in detail research on the production of xylitol from a country-specific raw material - Pineapple Cores, while the process of obtaining the target product is based on fermentation. The authors found that the highest yield of xylitol was obtained after enzymatic hydrolysis, and not acid hydrolysis of raw materials. Commercial enzymes and yeast were used in the work, allowing to reproduce the results described in the article. The strength of the article is the clarity of the presentation of the results obtained and the authors' clear understanding of how they reached reliable conclusions. But the article needs improvement, so the specific comments are outlined below:
Comments:
1. In the annotation, the word "critical" should be replaced with "key". Usually, in the processing of lignocellulosic raw materials, the key step is the pre-treatment of the raw materials. In the case of Pineapple Cores, this is apparently not necessary.

Reply: we changed the word “critical” to ‘key”.

2. In the annotation, the method for determining the component composition of raw materials can be excluded, but it is necessary to include one sentence with a statement of the novelty of the results obtained.

Reply: we removed that method from the discussion section.

3. In the introduction, it is necessary to list the common raw material sources for xylitol and very briefly outline the technologies for obtaining xylitol from them. Then it will be more clear why the production of xylitol from Indonesia-specific raw materials can be considered as a new technology for the world community.

4. In section “2.6. Analysis method" does not specify a method for determining lignin.

Reply: Using the Van Soest method we can determine the percentage of cellulose, hemicellulose, and lignin as well.

4. I recommend that the authors exclude the designation of components in the fig. 2 photos at a scale of 50 microns, but in the text it is possible to describe the fibers observed by the authors in words.

Reply: we excluded the designation of components in fig. 2 based on your suggestion. Actually, all photos have the same magnification.

 

Reviewer 2 Report

1. Authors did not mentioned about Scanning Electron Microscopy in materials and method section.

2. All microbe names should be in italics

3. The data given seems not statisticaly analyzed, indicate the values with different letters indicating significance at P-vlaues.

 

Author Response

First of all, thank the reviewers who have taken the time to review our manuscript and provide reviews to improve the quality of the manuscript. The following are our answers to questions asked by reviewers.

1. Authors did not mentioned about Scanning Electron Microscopy in materials and method section.

Reply: we have mentioned it in 2.6 Analysis method, “The OPEFB surface was examined with a scanning electron microscope (JEOL, JSM-6330F; Japan) before and after several processes.”

2. All microbe names should be in italics

Reply: we have corrected all microbes’ names to be in italics style including in references.

3. The data given seems not statisticaly analyzed, indicate the values with different letters indicating significance at P-vlaues.

Reply:  All data were analyzed statistically using a p-value less than 0.005. Indeed, some data are not significantly different, and we mentioned them in the discussion section.