Whey as a Carrier Material for Blueberry Bioactive Components: Incorporation in White Chocolate

Round 1

Reviewer 1 Report

Line 60-61, please mention the product.

During blueberry encapsule production, what was the blueberry juice/solids and WPC ratio?

Section 2.6 write reference for methodology.

In polyphenol and Antioxidant activity estimation, please check the unit. Is it microlitre or milli litre?

Section 2.12 write reference

Line 192: check spelling ‘od’ it should be ‘of’

In figure 2, write a sentence mentioning meaning of a,b,c and d.

Author Response

Dear Reviewer 1,

 

Authors appreciate your helpful comments and suggestions. We hope that we have successfully modified and improved our manuscript.

 

The original Reviewers’ comments are listed above (italic letters) and our responses to the comments follow below.

 

REVIEWER 1

(The green color is used in manuscript in order to indicate the revised parts of the text)

 

• Line 60-61, please mention the product.

We have inserted into the text systems whose stability is increased by proteins, including whey protein (Line 67-69).

 

• During blueberry encapsule production, what was the blueberry juice/solids and WPC ratio?

The ratio was 75:25 juice:whey. We inserted that information into the text (Lines 105-107).

 

• Section 2.6 write reference for methodology.

The reference for methodology is provided (Line 148). And also for 2.7 (Line 154).

 

• In polyphenol and Antioxidant activity estimation, please check the unit. Is it microlitre or milli litre?

It is microliter (µL). Microtiter plate was used.

 

• Section 2.12 write reference

We did not provide the reference in the text previously since there are no studies on the examination of oxidation stability of chocolate using the RapidOxy 100 device. We adjusted the test parameters by modifying the parameters given by the device manufacturer for oxidation stability of cocoa mass (Anton Paar: RapidOxy 100 - Oxidation Stability of Cocoa Mass and Vanilla). The only difference is that we did not use the 5 g of the sample but we used 3 g because during the trials it turned out to be a better solution. We put that reference into the text (Line 211).

 

• Line 192: check spelling ‘od’ it should be ‘of’

Thank you very much, we have corrected the error (Line 224).

 

• In figure 2, write a sentence mentioning meaning of a,b,c and d.

Yes, we inserted the sentence below the Figure 2, mentioning the meaning of a,b,c, and d (Line 326).

Reviewer 2 Report

Whey as a carrier material for blueberry bioactive components: 3 incorporation in white chocolate

 

The paper can be published only after major corrections including additional experimental work.

 

Abstract: The paper is interesting and consists of significant amount of studies that can relate well to the food technology pertaining to chocolate processing. But it is not captured well by the abstract. The abstract should dwell upon the results in greater detail but in a more succinct language. Also, the reason for using whey in particular for encapsulating blueberry juice should be elucidated succinctly, why it is important to use whey – and why blueberry juice cannot be used directly. How this opens up a pathway to incorporation of various dietary / fruit components in white chocolate.

 

 

Introduction : The introduction needs to dwell upon why it is not easy to directly disperse blueberry juices in white chocolate body. What other works have been done to use materials similar to whey as dispersing agents and what have been the results thereof and limitations thereof? These technical details will make the introduction much richer and pertinent to the argument for the paper.

 

Figure 1 : How does the casson values affect the processing of white chocolate. There are plenty of data in standard literature that showcases the effect of rheology on the processing and tec=xtural properties. How wil the dispersion of BB juice affect the same in comparison to the results from literature. Additionally, I think a data point need to be included that disperses whey in chocolate without any blueberry juice = CB0 (ie 0% blueberry juice). This acts as a control that separates out the effect of the carrier whey Vs the carrier + encapsulate.

 

There is also a need for general solubility data of blueberry juice inside whey – that is the whey – blueberry juice encapsulate (before being dispersed in the white chocolate). The process of the dispersion of blueberry juice inside the whey to create the encapsulate needs to be mentioned as well.

 

 

 

Oxidative stability : The Oxidation induction experiment is interesting but as far as the value of blueberry juice in inducing oxidative stability goes, it need to be backed up by additional long term stability studies carried out over at least 10 -15 days in an oxidation chamber, wherein the test results include remnant polyphenols in the chocolate.

 

 

Author Response

Dear Reviewer 2,

 

Authors appreciate your helpful comments and suggestions. We hope that we have successfully modified and improved our manuscript.

 

The original Reviewers comments are listed above (italic letters) and our responses to the comments follow below.

REVIEWER 2

(The yellow color is used in manuscript in order to indicate the revised parts of the text)

 

• Abstract: The paper is interesting and consists of significant amount of studies that can relate well to the food technology pertaining to chocolate processing. But it is not captured well by the abstract. The abstract should dwell upon the results in greater detail but in a more succinct language. Also, the reason for using whey in particular for encapsulating blueberry juice should be elucidated succinctly, why it is important to use whey – and why blueberry juice cannot be used directly. How this opens up a pathway to incorporation of various dietary / fruit components in white chocolate.

In accordance with your suggestion, we have explained in the abstract the reason for using whey for encapsulating blueberry juice and why blueberry juice cannot be used directly (Lines 19-22). We also inserted a sentence that this opens up a pathway of incorporation of various dietary / fruit components in white chocolate (at the end of the Abstract).

 

• Introduction: The introduction needs to dwell upon why it is not easy to directly disperse blueberry juices in white chocolate body. What other works have been done to use materials similar to whey as dispersing agents and what have been the results thereof and limitations thereof? These technical details will make the introduction much richer and pertinent to the argument for the paper.

Thank you for your observation, it was really a deficiency, which we hope that is now corrected in proper way (Lines 77-92).

 

• Figure 1: How does the casson values affect the processing of white chocolate. There are plenty of data in standard literature that showcases the effect of rheology on the processing and textural properties. How will the dispersion of BB juice affect the same in comparison to the results from literature. Additionally, I think a data point need to be included that disperses whey in chocolate without any blueberry juice = CB0 (ie 0% blueberry juice). This acts as a control that separates out the effect of the carrier whey Vs the carrier + encapsulate.

We inserted into the text how Casson viscosity affect the processing of chocolate (Lines 221-223, 270-272).

Also, we gave some comparisons of the impact of BB juice on chocolate viscosity with results from literature (Lines 274-280).

We absolutely agree with your statement that we should have used pure whey in the production of white chocolate. We will definitely have control sample of chocolate only with carrier in the future experiments. Unfortunately, we can't do that experiment now because we did this research a long time ago and now we can't get completely the same chocolate mass and whey as they were then.

 

 

• There is also a need for general solubility data of blueberry juice inside whey – that is the whey – blueberry juice encapsulate (before being dispersed in the white chocolate). The process of the dispersion of blueberry juice inside the whey to create the encapsulate needs to be mentioned as well.

Thank you for your comment. However, the solubility experiments were not performed so data is not available. The ratios juice:whey were determined in preliminary study (data not shown). However, the encapsulation process was explained in experimental part.

 

• Oxidative stability: The Oxidation induction experiment is interesting but as far as the value of blueberry juice in inducing oxidative stability goes, it need to be backed up by additional long term stability studies carried out over at least 10 -15 days in an oxidation chamber, wherein the test results include remnant polyphenols in the chocolate.

The reviewer's proposal for long-term determination of oxidative stability is justified but unfortunately, we are not in technical capacity now to carry out the long-term stability studies in oxidation chamber as suggested by the reviewer.

The results obtained using the RapidOxy100 device are relative, and they only show which sample is more oxidatively stable under the given conditions.

Reviewer 3 Report

Jovanović et al. reported how the incorporation of blueberry encapsulates changed the rheology, textural characteristics, melting behavior, color, antioxidant capacity, oxidation stability, sensory characteristics of white chocolates, and most importantly, the nutritional value. The narrative flows well and the scientific results are sound. I do have some comments on the English writing and some of the Figures (please see my comments below), but I have no big concerns about this manuscript and would recommend its publication in Sustainability.

 

(1)   The last sentence of the first paragraph of the abstract is unclear (Blueberry encapsulates (B) have been incorporated in white chocolate, replacing 8% (C-B8) and 10% (C-B10) of chocolate). What do you mean by “incorporated” and “replacing”? Replacing what type of chocolate? White chocolate? Please consider rewriting it to make it flow better.

 

(2)   Line 61-62: the following sentence is unclear (Whey is as a natural byproduct of cheese production where the amount of whey makes almost 90% of used milk). What do you mean by “the amount of whey makes almost 90% of used milk”? Please consider rewriting it to make it flow better.

 

(3)   Section 2.1: Please provide the source or reference indicating where the “blueberry juice encapsulated on whey (B)” come from.

 

(4)   Line 84: I think it should be “5.1% moisture” instead of “5.1 moisture”.

 

(5)   Line 195-196: “C-B8” and “C-B10” that appeared in Figure 1 were not called out in the main text.

 

(6)   Line 212: “The both amounts” reads confusing. Please consider rephrasing it.

 

(7)   Figure 2b: missing axis labels.

 

(8)   Section 3.5: Call out the data in Table 3 to support the following statement: “While the polyphenol content in C-B10 was increased 2.7 times compared to white chocolate, the antioxidant capacity was increased 5.2 times”.

 

(9)   Just out of curiosity: are there any toxicity studies on those chocolates? I know blueberry is apparently non-toxic, but is it necessary to have some animal toxicity studies to compare the normal white chocolate and the blueberry-enriched white chocolate? (Just my thought, it is not required for this study, since it is primarily a food science project).

Author Response

Dear Reviewer 3,

 

Authors appreciate your helpful comments and suggestions. We hope that we have successfully modified and improved our manuscript.

 

The original Reviewers comments are listed above (italic letters) and our responses to the comments follow below.

Jovanović et al. reported how the incorporation of blueberry encapsulates changed the rheology, textural characteristics, melting behavior, color, antioxidant capacity, oxidation stability, sensory characteristics of white chocolates, and most importantly, the nutritional value. The narrative flows well and the scientific results are sound. I do have some comments on the English writing and some of the Figures (please see my comments below), but I have no big concerns about this manuscript and would recommend its publication in Sustainability.

• The last sentence of the first paragraph of the abstract is unclear (Blueberry encapsulates (B) have been incorporated in white chocolate, replacing 8% (C-B8) and 10% (C-B10) of chocolate). What do you mean by “incorporated” and “replacing”? Replacing what type of chocolate? White chocolate? Please consider rewriting it to make it flow better.

Thank you very much for this suggestion, we rewritten this sentence to make it flow better for the readers (Line 22).

• Line 61-62: the following sentence is unclear (Whey is as a natural byproduct of cheese production where the amount of whey makes almost 90% of used milk). What do you mean by “the amount of whey makes almost 90% of used milk”? Please consider rewriting it to make it flow better.

Yes, we agree with this comment again. We though that cheese making process produces large amount of by-product called whey. From 100% of used milk for cheese production, 90% is liquid whey. We added some information in that sentence (Lines 70-71).

• Section 2.1: Please provide the source or reference indicating where the “blueberry juice encapsulated on whey (B)” come from.

We provided that information (Lines 101-102).

• Line 84: I think it should be “5.1% moisture” instead of “5.1 moisture”.

Thank you. Corrected! (Line 111)

• Line 195-196: “C-B8” and “C-B10” that appeared in Figure 1 were not called out in the main text.

We wrote C-B8 and C-B10 in the main text (Line 228).

• Line 212: “The both amounts” reads confusing. Please consider rephrasing it.

Thank you. We rephrased it (Line 245).

• Figure 2b: missing axis labels.

Thank you very much, we added “Volume” on the Figure 2a.

• Section 3.5: Call out the data in Table 3 to support the following statement: “While the polyphenol content in C-B10 was increased 2.7 times compared to white chocolate, the antioxidant capacity was increased 5.2 times”.

The sentence is revised as suggested (Line 360-362).

• Just out of curiosity: are there any toxicity studies on those chocolates? I know blueberry is apparently non-toxic, but is it necessary to have some animal toxicity studies to compare the normal white chocolate and the blueberry-enriched white chocolate? (Just my thought, it is not required for this study, since it is primarily a food science project).

No, we didn’t do the toxicity studies on those chocolates. We didn't even think about that because white chocolate consists of cocoa butter, which is very expensive, high quality and sustainable for years and also contains powdered milk, which is very stable, also powdered sugar which is also very stable and natural emulsifier lecithin. Whey is also natural product and blueberry juice also. But, however, it might be good to do some animal toxicity studies in the future to compare the normal white chocolate and the blueberry-enriched white chocolate.

Round 2

Reviewer 2 Report

can be accepted