Incorporation of Acid Whey Yogurt By-Product in Novel Sauces Formulation: Quality and Shelf-Life Evaluation

Round 1

Reviewer 1 Report

Manuscript presents interesting research results. However, the Authors need to make some significant changes. The chapter in the discussion of the results has been correctly described by the Authors. However, despite this, a lot of changes are recommended in the chapter "Materials and Methods".

·         Abstract: It's too long. I propose that the Authors focus on specific results.

·         Line 29: are the 2015 data still up-to-date? Perhaps it is worth introducing newer literature.

·         Line 82-85: not enough information. What is the purpose of the research? Why is the Authors' research important? Recommendations?

·         In introduction The Authors focused on the use of whey. There is no literature data on tomato sauces and other. Introduction in its current form does not correlate with the purpose of the research at all.

·         Line 100: which herbs? Clarify. Too little information.

·         How large samples were taken for testing?

·         Line 128: luminosity? L is lightness.

·         Line 204: Please add more details.

·         Line 235-240: Not enough information. How old were the panellists? How many men and women were there? What sample sizes did they receive for evaluation? Was the mouth rinsed with water during the assessment? Or crackers? On what basis were these specific descriptors selected?

·         Was informed consent to participate in the research obtained? Is there an approval from the relevant Ethics Committee? Please enter your consent number.

·         Line 405: Why? Please explain.

·         Line 471: "Nutritional parameters", is this a correct?

·     Line 512: The microscopic images appear overexposed. Can Authors add more authentic images to the manuscript?

·     Conclusions are too long. There are no recommendations for future research. The conclusions do not correlate with the Introduction chapter.

 

Author Response

 

18/11/2022

Sustainability MDPI, Special Issue: “Food Security and Environmentally Sustainable Food Systems”

Ms. Ref. No.: sustainability-2005056

Title: Incorporation of acid whey yogurt by-product in novel sauces formulation: Quality and shelf-life evaluation

Response to reviewers

Reviewer 1

Manuscript presents interesting research results. However, the Authors need to make some significant changes. The chapter in the discussion of the results has been correctly described by the Authors.

We would like to thank reviewer 1 for his/her time and effort in reviewing our work. We believe that the issues pointed out contributed to the significant improvement of the quality of our manuscript.

However, despite this, a lot of changes are recommended in the chapter "Materials and Methods"

• Abstract: It's too long. I propose that the Authors focus on specific results.

Reply: Abstract was reviewed and rewritten as suggested by the reviewer. In the revised manuscript, the abstract included briefly all obtained remarks from this study, highlighting the most significant ones.

• Line 29: are the 2015 data still up-to-date? Perhaps it is worth introducing newer literature.

Reply: A more current and up-to-date reference was added and new data about acid whey waste quantities received by US market replaced the previous one.

Lindsay, M. J., Walker, T. W., Dumesic, J. A., Rankin, S. A., & Huber, G. W. (2018). Production of monosaccharides and whey protein from acid whey waste streams in the dairy industry. Green Chemistry, 20(8), 1824-1834.

• Line 82-85: not enough information. What is the purpose of the research? Why is the Authors' research important? Recommendations?

Reply: We thank reviewer for his/her valuable comment. The importance of this study was revised and rewritten in Lines 95-108 in order to be more highlighted.

“The current research targeted to the development of new food products by adding acid whey as a main food ingredient. There are no similar products available in the market. The development of two different widely consumed sauces was studied: a tomato-based sauce with the addition of pasteurized liquid AW and a white sauce (oil-to-water emulsion) with the addition of AW powder (freeze dried AW). A thorough research was conducted, evaluating: i) the potential of using AW as a food ingredient with part or full substitution of major ingredients that do not offer (i.e. water in tomato sauces) or act negatively (i.e. oil in white sauces) on the functionality of the products, ii) the impact of AW addition on the quality, organoleptic characteristics, shelf life and nutritional profile of both novel sauces. The impact of this research is double-edged, since firstly it proposes the use of AW as an ingredient in the production of value-added food products at a higher scale and secondly it offers an alternative solution for the valorization of a yoghurt production by-product with serious environmental concerns.”

• In introduction The Authors focused on the use of whey. There is no literature data on tomato sauces and other. Introduction in its current form does not correlate with the purpose of the research at all.

Reply: A small paragraph and relevant references for the sauces in general was added. The reason for selecting that kind of products as case studies is highlighted in the Introduction section (Introduction Section in Lines 90-94).

“Sauces or dressings are of high demand and convenient food products consumed worldwide. Sauces are mainly used as toppings in various foods, increasing their attractiveness and tastiness. For the relevant industries the production of sauces with high added value compounds is of increased interest. These compounds could act as functional ingredients in final ready to eat products meeting also the consumers demand for healthy products.”

Sikora, M., Badrie, N., Deisingh, A. K., & Kowalski, S. (2008). Sauces and dressings: a review of properties and applications. Critical reviews in food science and nutrition, 48(1), 50-77.

Mirzanajafi-Zanjani, M., Yousefi, M., & Ehsani, A. (2019). Challenges and approaches for production of a healthy and functional mayonnaise sauce. Food science & nutrition, 7(8), 2471-2484.

• Line 100: which herbs? Clarify. Too little information.

Reply: The herbs used for the formulation of white sauces were: 0.5% garlic powder, 0.5% parsley, 0.5% rosemary (also 0.3% salt was added as a condiment). This information was added in the revised manuscript, as suggested by the reviewer in Lines 129-131.

• How large samples were taken for testing?

Reply: From all tested products, sampling was conducted at appropriate time intervals throughout the whole shelf life study. Each sample was approximately 100 g in glass containers, thus it was sufficient quantity to evaluate them in terms of microbial growth, quality indices and sensory parameters deterioration. This information was added in Line 144.

• Line 128: luminosity? L is lightness.

Reply: It was replaced as suggested by the reviewer in Line 159.

• Line 204: Please add more details.

Reply: A more precise description was added as suggested by the reviewer in Lines 237-246.

“Microstructures of novel white sauces were observed through optical microscopy using an Olympus BX40 Clinical Microscope with an x100 magnification, equipped with an Olympus DP72 digital camera. All the pictures were taken on the same day of sample preparation and at the end of their storage. A drop of each sample was placed in the microscope glass slide and covered with a coverslip to avoid the mobilization of droplets. Then, the focus knob was adjusted to get a clear view field.”

• Line 235-240: Not enough information. How old were the panellists? How many men and women were there? What sample sizes did they receive for evaluation? Was the mouth rinsed with water during the assessment? Or crackers? On what basis were these specific descriptors selected? Was informed consent to participate in the research obtained? Is there an approval from the relevant Ethics Committee? Please enter your consent number.

Reply: A more in detail description of sensory evaluation procedure was added (Lines 274-289). The sensory evaluation was performed by trained panel members of the Institute of Technology of Agricultural Products ELGO-DEMETER. These panelists perform sensory evaluation testes randomly, at least twice per month in various food products. Each time the evaluation is performed, a written consent form is provided to them to be informed on the products that will be evaluated and the forms are signed by all of them (there is a record of all these hard-copies). There was no need for approval of the evaluation from the Ethics committee of the Institute, since it was conducted in a volunteer basis, so each of the member of the panel was well informed on what was about to evaluate and accepted it by signing the relevant consent form. This is the typical procedure followed in most cases of published works when sensory evaluation is performed as one more parameter of the total multi-parameter (i.e. instrumental color analysis, instrumental texture analysis, microbiological analysis etc) evaluation of a product.

“Sensory evaluation was performed by an eight-member trained sensory panel, including individuals of both sexes (4 men and 4 women) from different ages ranging from 25 to 45 years old (average age was 31 years old). A typical sensory evaluation consent form was provided to the panelists to be informed on the products to be evaluated. According to ISO 8586:2012, a blind trial was performed for each studied sample in an accredited test room. Each panelist received approximately 20 g from each sample in a glass white plate, along with an organoleptic evaluation sheet featuring a variety of categories that the panel should use to review the products. These categories included appearance, taste, texture and smell and were scored while an overall rating and comments on comparison of the different samples were also asked. A 1–9 hedonic scale (1 the lowest quality score - 9 the highest quality score – 6 the organoleptically acceptable limit) was used and thoroughly explained in the panel before their evaluation (the way the panels should score was also written in the evaluation sheet). Between each trial the panelists rinsed their mouth with tap water. The mean values were calculated for every characteristic scoring received.”

• Line 405: Why? Please explain.

Reply: A briefly explanation was added in revised manuscript in Lines 468-471.

“Based on data cited in the literature (Martins, Jongen, & Van Boekel, 2000), Maillard reactions are always accelerated exponentially due to increased temperatures. This is attributed to the fact that an increase of temperature leads to proportional increase of the reactivity between the sugars and the amino acids group producing brown nitrogenous polymers and melanoidins.

Martins, S. I., Jongen, W. M., & Van Boekel, M. A. (2000). A review of Maillard reaction in food and implications to kinetic modelling. Trends in food science & technology, 11(9-10), 364-373.

• Line 471: "Nutritional parameters", is this correct?

Reply: In previous version of manuscript, it had been erroneously referred “nutritional parameters” and it was replaced by “nutritional composition” in whole manuscript accordingly, as suggested by the reviewer.

• Line 512: The microscopic images appear overexposed. Can Authors add more authentic images to the manuscript?

Reply: These are the authentic images that are delivered by the camera of microscope. We believe that they have sufficiently high analysis, depicting clearly the size of fat particles from each studied white sauce, helping us to explain and correlate our obtained results from the quality indices with the sauce structure. The addition of these images also aimed to make our manuscript more attractive and of high quality.

• Conclusions are too long. There are no recommendations for future research. The conclusions do not correlate with the Introduction chapter.

Reply: The conclusion section was reviewed and rewritten, as suggested by the reviewer, including all obtained remarks from this study more briefly, highlighting their potential benefits for dairy industry. Some suggestions were added in “Conclusions” concerning further research of new aspects/topics related to the objectives of this study.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Editor in Chief

This manuscript entitled "Incorporation of acid whey yogurt by-product in novel sauces formulation: Quality and shelf-life evaluation" given useful information for researchers and academia and article would be great contribution in discipline of food science and Technology. However, the opportunity for improvement is always there and I have suggested some major revisions.

·        Please avoid repetition.

·        Please check reference style throughout MS.

·        Italic all the scientific names.

·        Remove grammatical mistakes.

·        Need to rewrite the conclusion.

·        Need to improve the English language for better flow of literature.

-Lines 21-22: Nutrients were in higher concentrations for the both sauces, improving their health promoting profile (tomato sauces: up to 12.5% increase; white sauces: up to 8-fold increase in lactose content).

What is the relation between lactose content and health promoting profile? Need to rewriting and correction in the Abstract and Main Text (regarding to Table 3).

-   Table 1: Please explain the reason for the difference of pH and Acidity values between liquid acid whey and acid whey powder in the text using relevant references.

-   Please replace the “lipid” or “oil” phrases with “fat” in all over the manuscript.

-Lines 689-691: To conclude, based on the obtained results about the deterioration of quality and sensory characteristics of developed white sauces, the optimal fat substitution by AW powder was 10%.

According to table 5 and Fig. 8, the phase stability, protein, lactose and mineral contents of the sample formulated with 20% AW are higher compared with the sample manufactured with 10% AW. Please explain about this matter.

Sincerely,

 

Author Response

18/11/2022

Sustainability MDPI, Special Issue: “Food Security and Environmentally Sustainable Food Systems”

Ms. Ref. No.: sustainability-2005056

Title: Incorporation of acid whey yogurt by-product in novel sauces formulation: Quality and shelf-life evaluation

Response to reviewers

Reviewer 2

This manuscript entitled "Incorporation of acid whey yogurt by-product in novel sauces formulation: Quality and shelf-life evaluation" given useful information for researchers and academia and article would be great contribution in discipline of food science and Technology.

We would like to thank reviewer 2 for his/her time and effort in reviewing our work. We believe that the issues pointed out raised valid concerns, and their correction contributed to the significant improvement of the quality of our manuscript.

However, the opportunity for improvement is always there and I have suggested some major revisions. 

• Please avoid repetition.

We tried to avoid repetition in some points throughout the whole manuscript.

• Please check reference style throughout MS.

Checked

• Italic all the scientific names.

Done

• Remove grammatical mistakes.

We improved our manuscript with regards grammatical errors.

• Need to rewrite the conclusion.

Conclusion was revised accordingly.

• Need to improve the English language for better flow of literature.

We did our best in improving the English language throughout the whole manuscript.

 

• Lines 21-22: Nutrients were in higher concentrations for the both sauces, improving their health promoting profile (tomato sauces: up to 12.5% increase; white sauces: up to 8-fold increase in lactose content).What is the relation between lactose content and health promoting profile?Need to rewriting and correction in the Abstract and Main Text (regarding to Table 3).

Reply: We strongly agree with this comment of the reviewer. This sentence was removed and rewritten as follows in Lines 17-21:

“Both AW-substituted sauces were of high quality and of higher nutrients content compared to conventional products, improving their health promoting profile (tomato sauces: up to 3-fold in-crease; white sauces: up to 5-fold increase in calcium content; increase in essential amino acids content in both sauces due to AW addition).”

Based on data from literature, AW has health promoting properties from some selected components. Its health benefits delivered by selected minerals contained in acid whey, such as calcium, magnesium and phosphorus. Moreover, AW provides a plethora of bioactive ingredients for incorporation into functional food products. AW also contains whey proteins that are considered source of some essential amino acids such as threonine (~44 mg/100 g dm AW) and arginine (~81.11 mg/100 g dm AW).

Rocha-Mendoza, D., Kosmerl, E., Krentz, A., Zhang, L., Badiger, S., Miyagusuku-Cruzado, G., ... & García-Cano, I. (2021). Invited review: Acid whey trends and health benefits. Journal of Dairy Science, 104(2), 1262-1275.

• Table 1: Please explain the reason for the difference of pH and Acidity values between liquid acid whey and acid whey powder in the text using relevant references.

Reply: Liquid AW is coming directly from the straining of yoghurts, while for AW in a powder form a series of steps including condensation by reverse osmosis, vacuum drying, crystallization and freeze drying were used. These processing steps might have a slight effect on the pH-value of the product (AW in powder) since part of acids might be retained in the pressurized part of the membrane. Another potential explanation could be that these AWs used in our study are coming from different yoghurt batches produced, thus slight different pH value of the strained AW and this is in accordance to the literature where similar differences have been reported between AW batches (Menchik et al., 2019). (Lines 355-363)

Menchik, P., Zuber, T., Zuber, A., & Moraru, C. I. (2019). Composition of coproduct streams from dairy processing: Acid whey and milk permeate. Journal of dairy science, 102(5), 3978-3984.

• Please replace the “lipid” or “oil” phrases with “fat” in all over the manuscript.

Reply: “Lipid” and “oil” phrases were replaced with “fat”, as suggested by the reviewer. This issue was carefully checked in the whole manuscript.

• Lines 689-691: “To conclude, based on the obtained results about the deterioration of quality and sensory characteristics of developed white sauces, the optimal fat substitution by AW powder was 10%”. According to table 5 and Fig. 8, the phase stability, protein, lactose and mineral contents of the sample formulated with 20% AW are higher compared with the sample manufactured with 10% AW. Please explain about this matter.

Reply:  We thank reviewer for this valuable comment. A more in detail description was added in revised manuscript in Lines 768-782 in order to justify the selection of optimal 10% AW substitution instead of 20% w/w.

“The addition of AW powder in the newly developed white sauces improved significantly their nutrients’ content and their emulsion stability. For the highest fat substitution (20%) by AW a 8-fold increase in lactose and calcium content was observed, while simultaneously the food emulsion depicted stability throughout the shelf life of those sauces. Although 20% AW-substituted white sauces had improved nutritional profile, their shelf life was less compared to the other samples mainly due to significant color alteration because of Maillard reaction. This resulted in almost 5-months shorter shelf life compared to the 10% AW substitution. The high lactose content led to acceleration of Maillard reactions and consequently to their non-acceptable browning color, as well to off-flavors due to Maillard products in shorter time than the rest ones.”

Author Response File: Author Response.docx

Reviewer 3 Report

No comment

Author Response

18/11/2022

Sustainability MDPI, Special Issue: “Food Security and Environmentally Sustainable Food Systems”

Ms. Ref. No.: sustainability-2005056

Title: Incorporation of acid whey yogurt by-product in novel sauces formulation: Quality and shelf-life evaluation

Response to reviewers

Reviewer 3

No comments

We would like to thank reviewer 3 for his/her time and effort in reviewing our work.

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Now, the manuscript is suitable for publication in this journal.

Reviewer 2 Report

Thank you.