Preparation and Evaluation of Microcapsules Encapsulating Royal Jelly Sieve Residue: Flavor and Release Profile

Round 1

Reviewer 1 Report

The topic is very interesting and within the scope of this journal. 

Thanks for considering me to review this article.

Specific comments are as below:

 

Abstract

Lines beteween 9 and 11: ”To improve the flavor of royal jelly residue and eliminate the adverse effects after eating, we successfully encapsulated it with gelatin and Arabic gum using complex coacervation and  spray drying techniques”.  This paragraph should be rewritten. It is expressed in a very coloquial way.

Introduction

The initial motivation in favor of the need to encapsulate with gelatin and arabic gum using complex coacervation and spray drying techniques should be strengthened because is very weak at the present time. It is not clear from the introduction, whether and why it is necessary to encapsulate in this way in a deep way. The benefits and uses of RJSR are not well developed in the introduction. Maybe it is important to add some preview references to power the motivation.

 

Line 35: “Consumers often complain that eating RJ could cause vomiting, but symptoms are less severe for sieved RJ, which is obtained by sieving RJ through a 125 μm mesh screen” Please explain some references to explain this affirmation. It is not documented.

 

Materials and Methods

 

Pretreatment of RJSR

 

References and equipements related to ultrasounds, centrifuge and pH meter are not included.

 

Preparation of microcapsules

 

Line 68 and 69: “The process parameters of gelatin Arabic gum microcapsule were described by [12] and [13] ,  with modifications” These modifications should be included.

 

Efficiency of microencapsulation

Line 85 and 86. I dont know if “detective wavelength was 210 nm “ is related to PDA detector or other detectors.

 

Line 86: Please be more concise with the column characteristics.

 

Sensory evaluation

 

This part should be developed. It is not well described in relation to the methodology. Could you develope/cite in the firt paragraph the evaluated parameters?

 

Results and discussion

 

Particle size

 

Line 182: Please be more concise with this affirmation. You have to explain this affirmation. “Particle size has been shown to affect flavor [24]”.

 

Electronic nose

 

Line 208: “ On the contrary, W1W and W2W  had a great contribution to LA1, while W1S and W2S had a great contribution to LA2”.Please could you complete this affirmation? (indicate the value between parenthesis).

 

Line 209-210: However, the 210 response value of microcapsules was significantly smaller than that of the mixture”. Please could you complete this affirmation? (indicate the value between parenthesis).

 

 

Electronic tongue

 

Line 226-227: “However, the difference between the response values of bitter and aftertaste-B was not significant” . Statistic analysis is not reported in the results, please be more concise with “Significant or non significant results”. 

 

Line 230-232: “In Figure 8 (a), astringency, aftertaste-A,bitterness, and aftertaste-B had a great contribution to LA1 and LA2, while the contribution rates of other indicators were relatively small”. Please be more concise with how small the value is…

All the results obtained have nor been deeply compared with other researchers, please develope this part.

 

Some date are missing related to differents results. In some cases he authors indicate some results are smaller or higher but these results are not well disussed or the data are not highlated. 

Author Response

Dear Reviewer:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled "Preparation and evaluation of microcapsules encapsulating royal jelly sieve residue: Flavor and release profile" (applsci-601807). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the manuscript unless we specifically state it. The main corrections in the paper and the responds to the reviewer’s comments are put in the attach file.

Thank you again for your detailed and constructive comments. We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. And we marked in red in revised manuscript.

 

Yours sincerely,

Rongjun He

Author Response File: Author Response.pdf

Reviewer 2 Report

The article applsci-978612, titled: Preparation and evaluation of microcapsules encapsulating royal jelly sieve residue: Flavor and release profile.

 

In this paper, microcapsules encapsulating royal jelly sieve residue by complex coacervation and spray dry techniques are synthetized to avoid spicy and astringency taste and pungent odor. The encapsulation yield and encapsulation efficiency showed a good percentage of encapsulation. The sensorial studies showed an improvement of taste and the simulated digestion proved that the microcapsules resist gastric environmental however they would be absorbed in the intestine. The authors conclude that these microcapsules can be used to develop mild flavor products of royal jelly.

 

In my opinion, this paper is adequate to be published with minor revision, but some issues require attention before it is acceptable.

 

Minor revision:

• In the abstract, the authors present the digestion results before than sensorial results but in the section of results and discussion are backwards. This is confused. Please, follow the same order.
• Add in the introduction the importance of Royal Jelly in the economy of exportation in China.

China is unanimously acknowledged as being the leading world producer and exporter of RJ, which it sells at a highly competitive price. Chinese production of RJ is estimated at 2000 tonnes/year (a quantity that represents over 60% of production worldwide), almost all of which is exported to Japan, the United States and Europe (Ramadan and Al-Ghamdi 2012).

• In material and methods, in the equation 1. The parenthesis has been lost. It is not the same, please correct it. See reference number 16 (Du, Y.L., et al., 2018)
• Line 137. In the SGF preparation, the authors must take account that SGF must be kept at 4ºC until its use in order to avoid its autolysis. Please, specific in the text.
• Lines 172-173. The authors say, “Those microcapsules embedded oil were easier to show a perfect spherical shape than ours [13, 22]” Discuss what the other authors say and compare to their results.
• Lines 175-176. The authors say, “However, there were hardly any holes on microcapsule surfaces, indicating that these wall-materials could offer protection against leakage [23].”

Compare and discuss why these results are similar. What it is found in this reference number 23.

• Section 3.2.3. Particle size. Add the polydispersity index (PDI). And comment it.

In the conclusion, the authors say, “the RJSR microcapsule had a small mean particle size and a more uniform particle size distribution (10–30 μm).” But to affirm a more uniform particle size distribution, they should give the PDI.

• Line 253 add reference.

 

 

Author Response

Dear Reviewer:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled "Preparation and evaluation of microcapsules encapsulating royal jelly sieve residue: Flavor and release profile" (applsci-601807). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the manuscript unless we specifically state it. The main corrections in the paper and the responds to the reviewer’s comments are put in the attach file.

Thank you again for your detailed and constructive comments. We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. And we marked in red in revised manuscript.

 

Yours sincerely,

Rongjun He

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors conducted an interesting study that attempted microencapsulation using gelatin and Arabic gum to improve the sensory index of royal jelly residues. This topic is very interesting and this research will potentially help us to improve the taste of the food we consume. The objectives and methods of the study are carefully presented, and the results supported the aim of the work.

However, some points inside the manuscript should be clarified.

 

Major points

1) English needs a major revision. There are some syntax errors throughout the manuscript and the writing style is also not appropriate. Professional English editing service is recommended.

 

2) In this study, the authors used gelatin and Arabic gum for encapsulation. Many encapsulating agents have been reported, such as chitosan, protein, ascorbic acid, etc. As we are well aware, the choice of encapsulation material is important for capsule efficiency, capsule stability, and purpose. The background behind the author's choice of two materials for this study and the properties of these materials should be described in more detail in the introduction.

 

3) A brief description of the royal jelly market size and the production process of royal jelly residues should be added to the introduction.

 

4) The authors expressed the Y-axis in Figure 3 as VOL%. However, since it seems that the particle size distribution in Figure 2 cannot be accurately explained, it is recommended to express it in terms of frequency.

 

5) Line 247: Why does the electrostatic interaction between GE and AG increase in acidic conditions? Specifically, how does it relate to pH?

 

6) As mentioned in the manuscript, what are the features of the core material that can confirm the internal structure?

 

7) For easier access to readers and improved citation, the results of this study should be presented in a summary table compared to other encapsulation studies. In particular, various types of encapsulation (simple microcapsule, multicore microcapsule, multiwall microcapsule, etc.) can be used in the food industry. The advantages of the type of microcapsules used in this study and their comparison with other studies should be discussed in the section of ‘Results and Discussion’.

 

Minor points

8) Line 53: Please define, HPLC appears the first time in the manuscript.

 

9) Line 54: What is the EC number of the enzyme used in the study?

 

10) Line 60: As mentioned in the manuscript, RJSR is not suitable for a feasibility test due to size issues. What particle size is suitable for your study?

 

11) Line 74: Why did the authors set the pH to 4.1?

 

12) Line 75: What equipment was used to bring the mixture to a temperature of 10°C?

And what is the role of glutamine transaminases?

 

13) Is the enzyme activity stable at pH 4.1 of the mixture?

 

14) Line 153: How to remove free RJSR for analysis?

 

15) Line 158: What is the thickness of the capsule's shell wall? Is it controllable?

 

16) The author should follow the reference format according to MDPI guidance.

Author Response

Dear Reviewer:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled "Preparation and evaluation of microcapsules encapsulating royal jelly sieve residue: Flavor and release profile" (applsci-601807). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the manuscript unless we specifically state it. The main corrections in the paper and the responds to the reviewer’s comments are put in the attach file.

Thank you again for your detailed and constructive comments. We tried our best to improve the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. And we marked in red in revised manuscript.

 

Yours sincerely,

Rongjun He

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I think everything is clear now

Reviewer 3 Report

This manuscript can be published with the author's modification.