Cloud Point Extraction as a Green Method for the Extraction of Antioxidant Compounds from the Juice of Second-Grade Apples

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In my opinion, this is a very interesting article that presents an eco-friendly extraction method such as Cloud Point Extraction (CPE) to be applied to apples that do not meet consumer quality standards but still have potential for utilization, as demonstrated in the study (through the extraction of their bioactive compounds and their encapsulation using lecithin). The document provide some respectful comments aimed at improving the manuscript.

Comments for author File: Comments.pdf

Author Response

In my opinion, this is a very interesting article that presents an eco-friendly extraction method such as Cloud Point Extraction (CPE) to be applied to apples that do not meet consumer quality standards but still have potential for utilization, as demonstrated in the study (through the extraction of their bioactive compounds and their encapsulation using lecithin). The document provide some respectful comments aimed at improving the manuscript.

We would like to thank the reviewer for the positive feedback regarding our manuscript.

Below, I provide some respectful comments aimed at improving the manuscript:

1. Could you include in the introduction, after line 63, that other extraction techniques— such as solvent-based, enzymatic, or ultrasound-assisted methods—are commonly used but are not as environmentally friendly or may involve polluting solvents.

The specific paragraph has been thoroughly revised in terms of comparing modern extraction techniques, as requested by the reviewer. The text now emphasizes why CPE offers a greener alternative.

2. Line 96: should this section truly be titled 'Instrumentation'? From what I see, it covers parameter determinations such as pH, °Brix, and color. Therefore, each test should be described separately—for example, whether measurements were taken directly from the apple juice, performed in triplicate, etc. I suggest breaking down each analysis into individual descriptions rather than combining everything into a single paragraph.

The specific subsection has been removed from the manuscript and its content has been inserted to the corresponding subsection, aligning with the reviewer’s suggestion.

3. Line 116: Please specify the brand/model of the juicer used and the duration of operation. Additionally, indicate the filter specifications (pore size/mesh) employed in the

We added the cold-press juicer brand/model, operation time, and the filter specifications (pore size/mesh) in the Materials and Methods section.

4. Line 221-222: The values for active acidity, titratable acidity, and soluble solids are reported without standard deviation. Were measurements not performed in triplicate, or was this information inadvertently omitted?

We regret the omission. These measurements were performed in triplicate, and standard deviations are now included in the text to match Table 1.

5. Lines 223-224: The same applies to the L, a, and b values - these are reported without standard deviations.

Standard deviations for color parameters (L*, a*, b*) have been added to the Results text for consistency with the tables.

6. Line 272: Could you reference whether similar lecithin concentrations have been documented in previous research?

We included a recent reference (Karadag et al.) reporting 15% w/v lecithin for recovering bioactive compounds from olive mill wastewater and discussed its relevance to our formulation.

7. Line 336: Please include the numerical results in the text so readers don’t need to refer to the table for these values.

We now report the key numerical values directly in the Results text, while keeping the table for completeness.

8. I suggest including, if possible, a brief analysis of:
   • The required quantity of apples (in kg)
   • The resulting juice yield and extraction efficiencies
   • The economic viability for industrial implementation (including key scalability challenges)
   • Potential market pricing if commercialized as

We added a concise subsection summarizing the apple quantities used in our study, the resultant juice yield, and extraction efficiencies, and we discussed scalability, key cost drivers, and practical implementation considerations (simplicity of CPE, mild conditions, and low equipment cost). A rigorous pricing analysis depends on market-specific data and is beyond the scope of this study; we note it as an avenue for future work.

9. Could you please check whether newer references (from the last 5-7 years) could replace citations 16-18, 19-22, 26, 28-29, and 35? This would help ensure the work reflects contemporary research.

We updated the bibliography with newer references that better reflect recent advancements and aligned them with the revised discussion.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript "Cloud Point Extraction as a Green Method for the Extraction of
Antioxidant Compounds from Juice of Second-Grade Apples"

The idea of manuscript is advance, can be benifical in future- However, Englishe must be double checked

Comments for authors

Abstract: Sententences should be revised "A significant quantity of food is wasted worldwide each year. Much of this waste consists of fruit by-products or fruits that fail to meet consumer standards." for brtter understanding

Should be rewritten"Since apple waste, which also includes unsuitable for standard commercial sale apples of poorer quality (second-grade), is incapable of being disposed of in landfills and so adds to environmental strain [8]. Therefore, it is important to be utilized in any convenient 55
way. "

The introdcution should be brief and full of basic data regarding to study

-The materials and methods should be revised as per standard method--start from Raw materiaLS...............

The Figure 1, Figure 2 and Figure 3 should be in one graphic if possible

The discussion can be improved/modified using recent studies and mechanism

Also, the CPE method should be compared with previous green methods

The conclusion should be rewritten, thr current form look like discussion of results

The reference can be updated

In conclusion! the manuscript can be accepted after revision

Author Response

The manuscript "Cloud Point Extraction as a Green Method for the Extraction of Antioxidant Compounds from Juice of Second-Grade Apples"

The idea of manuscript is advance, can be benifical in future- However, Englishe must be double checked

We would like to thank the reviewer for the thorough examination of our manuscript. We have carefully revised the manuscript for English usage, clarity, and style.

Comments for authors

Abstract: Sententences should be revised "A significant quantity of food is wasted worldwide each year. Much of this waste consists of fruit by-products or fruits that fail to meet consumer standards." for brtter understanding. Should be rewritten"Since apple waste, which also includes unsuitable for standard commercial sale apples of poorer quality (second-grade), is incapable of being disposed of in landfills and so adds to environmental strain [8]. Therefore, it is important to be utilized in any convenient 55 way. "

These sentences have been rewritten for better understanding, as requested by the reviewer.

The introdcution should be brief and full of basic data regarding to study

The Introduction has been streamlined to present only essential background, the motivation for using CPE, and the study’s objectives, while integrating recent literature.

-The materials and methods should be revised as per standard method--start from Raw materiaLS...............

We reorganized Materials and Methods section.

The Figure 1, Figure 2 and Figure 3 should be in one graphic if possible

We retained separate figures for each optimization parameter to preserve clarity (distinct axes, ranges, and conditions) and to facilitate focused discussion.

The discussion can be improved/modified using recent studies and mechanism

We expanded the Discussion with recent references and included a plausible mechanism for partitioning and encapsulation in the CPE/lecithin system, linking observations to micellar/aggregate behavior and antioxidant polarity.

Also, the CPE method should be compared with previous green methods

CPE technique has been compared with other green extraction techniques, as recommended by the reviewer.

The conclusion should be rewritten, thr current form look like discussion of results

The Conclusion has been fully rewritten to succinctly summarize the main findings, highlight the advantages of the approach, outline limitations, and indicate practical implications and future work.

The reference can be updated

References have been updated to include recent work and to align with the revised narrative.

In conclusion! the manuscript can be accepted after revision

We would like to thank the reviewer for the positive feedback regarding the enhancement of our manuscript.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The co-authors revised the manuscript very well, now it can be accepted