Coffee-Flavoured Kombucha: Development, Physicochemical Characterisation, and Sensory Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript investigated the physicochemical and sensory characteristics of coffee flavored Kombucha with different formulations.

The study has been well designed and performed. However, there are still many points needed to be improved.

1. The current market offers a wide variety of flavored Kombucha. What makes coffee flavored Kombucha unique? What is the necessity of the research about coffee flavoured Kombucha?

2. Introduction: The content requires further organization, consolidation of relevant paragraphs, and an increase in previous researches about coffee flavoured Kombucha.

3. What specific gap in the field of Kombucha products and its processing technology does the paper address?

4. Why is coffee added at the first fermentation stage? Have comparative experiments been conducted to evaluate the effects of coffee addition at different stages of fermentation?

5. The non-coffee control formulation is need in the experiment. Please describe why there is no blank control formulation (non-coffee formulation).

6. Line 204: the references regarding the caloric value of soft drinks should be included.

7. Line 208-209: add the references about the sodium concentration of soft drinks.

8. Please discuss what are the reasons for the differences in physical and chemical properties and flavor characteristics of different formulations.

9. The Discussion and Results exhibit a certain level of redundancy. The important content in part of Discussion should be enhanced.

10. The format of Table 2, Table 3 and Table 4 should adhere to a three-line table structure.

Comments on the Quality of English Language

The writing language needs improvement.

Author Response

Dear editor, below are the answers to the respective questions.

I would like to thank you immensely for the peer review that can contribute to a better presentation of our research.

They follow below.

Thank you very much.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The research focused on the physicochemical, colorimetric, and sensory characteristics of the kombucha fermented with the addition of coffee infusion. A simple study design was used, where the coffee  was the only variable. Beverages were evaluated after 18 days of fermentation (5 days of aerobic fermentation and 13 days of anaerobic fermentation).

 The purpose and justification of the work are good. The materials and methods section sounds good. The statistics are robust and correctly applied. The discussion and conclusions are appropriate. In my opinion, the work can be published after corrections.

 Line 40: delete (2018)

Lines 41-45: Break this sentence into two separate sentences to make it easier to understand.

Line 72: Use Italics for Latin names (same line 182, 222, )

Figure 1: Check the space between numbers and units (same lines 101, 121, 193, …).

Line 104: 1.5 mL or 1,500 ml (Check the difference in the use of a dot or a comma in the numerical values ​​you provide) (same Table 1).

Line 107: delete: 0

Lines 65-68: What does specialty coffee mean? Are there differences in coffee production technology or only in quality compared to traditional coffees?

Table 1: coffee-flavoured instead of coffee-dlavoured.

Check the data on green tea and coffee infusions. Is it true that K3 contains 80 ml of green tea and 20 ml of coffee? According to the description in Figure 3, K4 contained the largest amount of coffee.

 

Line116: (Table 1) instead (table 01).

Lines 123-125: How was the percentage of green tea and coffee calculated?

Line 149: The samples, refrigerated at 7ºC, while Figure 4 shows a temperature of 5ºC.

Line 198: K4 instead of k4

Table 2: superscript lowercase letter   instead of   letter (same Table 3 and Table 4).

Tukey test (p = 0.05)  instead of   Tukey (5% significance) (see Material and methods line 187).

Line 214: "... and slightly more turbid 214 (L=86.9)". Note, however, that the L - luminosity parameter does not express the turbidity of the solution.

Figure 5 is redundant, it repeats the results presented in Table 4.

Line 287: delete (2005).

 

Line 287: Osterbauer et al. [42] while in the References it is in position [41].

 

Lines 289: Therefore, these colour-flavour interactions are probably “real”. - On the other hand, the influence of colour on the perception of taste and aroma can be eliminated by using appropriate lighting conditions during evaluation or even by assessing samples in containers made of dark glass.

Comments for author File: Comments.pdf

Author Response

Dear, below are the answers to the respective questions.

I would like to thank you immensely for the peer review that can contribute to a better presentation of our research.

They follow below.

Thank you very much.

Author Response File: Author Response.pdf