Development and Characterization of Pinhão Extract Powders Using Inulin and Polydextrose as Prebiotic Carriers

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The experimental work is comprehensive, covering physicochemical, physical, microstructural, and mineral characterization. However, several sections require clarification, deeper discussion, and minor corrections to improve readability before acceptance. The comments as follows:

1. The abstract should be revised wholly. There is no result presented in the abstract. State the value.
2. Line 48 to 50, give the value of the composition for carbohydrates, fibres and mineral. Also includes citation of the sentence.
3. The introduction is too generic. Transition of the spray dry to fermentation In the paragraph 3 is not clear. State the clear problem statement of this research.
4. Use standardized term either pinhao or its scientific name.
5. Section 2.1.1, why was the almond used in this study?
6. Why did the formulation used only 30% of bot carrier? What if the concentration increase or decrease? What happen if the carrier is mixed at certain concentration? The amount 30% is based on what? Why did the total formulation does not equal to 100%
7. Why did only one condition of Spray Dryer used in this study? Any optimization has been conducted?
8. Table 2 is unnecessary in the method. It should be explained during the discussion.
9. Clarify the unusual unit “Asher (g citric acid per 100 g)” in Table 3
10. Discussion is too generic. Explain the result in depth. A lot of factors can be influenced to the result which the authors did not explain. For ie; molecular weight differences between inulin and polydextrose on moisture adsorption and others.
11. SEM analysis. The images need scale bars and clear magnification labels.
12. Is there any shelf life study or sensory has been conducted in this study? Why did not include in this study? Or in vitro study?

Author Response

Dear reviewer, thank you for your consideration. The responses are in the document. Please see the attachment. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript presents a tudy on the spray drying of Araucaria angustifolia seed (pinhão) extracts using inulin and polydextrose as prebiotic carrier agents. The topic is original and relevant to the development of functional food ingredients from underutilized plant resources. The methodology is thorough, and the authors evaluated a comprehensive set of physicochemical, functional, morphological, and mineral properties of the produced powders. The results are clearly presented and supported with appropriate statistical analyses and literature context. The manuscript demonstrates novelty in exploring fiber-based carriers to improve the stability and nutritional potential of pinhão extract powders. Several improvements in background framing, methodological clarity, and limitations reporting could further strengthen the work. 

1. The authors could strengthen the background by emphasizing what differentiates this study from existing spray-drying studies using inulin/polydextrose on other plant matrices. Consider highlighting pinhão’s endangered-species context more carefully, especially regarding sustainability concerns.

2. Phenolic compound results need better contextual justification. Earlier, the abstract states “no phenolic compounds were detected,” but the results section shows quantifiable values (even if low). Please correct the mismatch and discuss expected stability during thermal processes more thoroughly.

3. Yield is a key industrial parameter for scalability and comparison across carriers. Please include the data regarding spray-drying yield.

4. Provide particle size distribution information (if possible) or acknowledge its absence as a limitation, since flowability and functional performance depend on it.

5. Explain practical application scenarios (e.g., beverages, nutritional powders) and environmental/economic implications more explicitly.

6. Table 6: why is there no quantity of S and Mn?

7. Questions for further discussion: (a) How does the choice of extraction temperature (≈55 °C) influence phenolic and starch solubilization?, (b) Were any challenges encountered regarding powder stickiness during spray drying, especially for polydextrose?, (c) Did the authors evaluate or consider adding thermal protectants or anti-caking agents beyond CMC?, (d) How do these powders influence the viscosity/rheology of potential food matrices?, (e) Were sensory evaluations or color acceptance studies considered for product development?, (f) Considering sustainability and conservation concerns for A. angustifolia, how scalable is raw material sourcing?
8. Minor comments regarding typos/grammatical errors: (a) Table 1: % inulin not "inulina", (b) Table 3: "Asher (g citric acid per 100 g)" do the authors mean "Ash (g minerals per 100 g)?, (c) Units in Table 5: The authors might mix “ug/g” and “µg/g” e.g. “Gallic acid (ug/g)” vs “Vanillic acid (µg/g)”. Please standardize all to “µg/g” (with the Greek µ) for consistency.

Author Response

Thank you for your consideration. The responses are in the document. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript investigates the effect of using inulin and polydextroseas carrier agents in the spray-drying process of Araucaria angustifolia (pinhão) extracts, focusing on physicochemical properties, powder characteristics, rehydration behavior, phenolic profile, and mineral composition. The study is clearly structured, with well-organized methodology and comprehensive analytical approaches. Overall, the manuscript presents meaningful findings that can contribute to the literature on functional food ingredients and spray-drying technology. However, several aspects need clarification or strengthening before the manuscript can be considered for publication.

1. Spray-drying parameters require more justification. The authors provide inlet/outlet temperatures and nozzle size, but should justify why these parameters were selected and whether preliminary trials or literature precedents guided them. Extraction temperature and rationale are unclear. Using 55 °C for aqueous extraction is acceptable, but the authors should discuss how this affects the integrity of bioactives, particularly phenolics or minerals. Carrier concentrations. Table 1 lists only “30% inulin or 30% polydextrose.” How was this value optimized? Were moisture problems or stickiness issues observed at lower concentrations? Phenolic extraction method is insufficiently described. Only 1 g sample with 80% methanol is used, how about the extraction yield or efficiency?
2. “Inulin forms more compact particles.” SEM images show some aggregation in both treatments, but the explanation about structural collapse and gel-forming ability needs quantitative support (e.g., particle size distribution), however, only base on qualitative SEM observation. “Polydextrose improves rehydration due to its amorphous structure.” While supported by wettability and dispersibility data, there are no DSC, XRD, or glass-transition analyses to confirm the amorphous nature of the powders. Phenolic content needs interpretation. The authors state “no phenolic compounds were detected as expected for raw pine nuts,” however, Table 5 shows several phenolics at trace levels.
3.  Lack of a control sample (extract without carriers). Without comparing to a non-carrier control, it is difficult to attribute changes exclusively to the carrier agents. No particle size distribution data. Flowability, density, dispersibility, and SEM morphology strongly depend on particle size. The absence of granulometry makes interpretation incomplete. No thermal analysis (DSC/TGA) is Necessary to justify claims about amorphous/crystalline structure and stability. Phenolic analysis is weak. Very low values close to LOQ and LOD. No discussion of possible degradation during spray drying. No comparison with literature values repetition in Results & Discussion should be condensed. A high number of references are used without a deeper mechanistic discussion. Some grammatical issues and long sentences could be improved for clarity.

Author Response

Thank you for your consideration. The responses are in the document. Please, see the attachment. 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

  This manuscript presents an interesting investigation into spray-drying of pinhão extracts using prebiotic carriers. The work is generally well-structured and addresses a relevant topic. However, several areas require attention before publication.

1. Page 1, lines 25-41: The abstract states that “no phenolic compounds were detected” in the samples, but in Table 5 you note that several phenolic compounds are quantified (gallic acid, vanillic acid, quercetin, etc.). Then later you mention that these compounds exist in very low concentrations, typical of almond tissue, but this is confusing. I recommend that you revise the abstract to accurately state that “phenolic compounds were detected in very low concentrations, compatible with raw almond tissue,” instead of claiming that they were not detected.
2. Page 2, lines 44-91: To increase clarity and impact, you can restructure your introduction. My suggestion is to start with the technological challenge or purpose of the study, and then use historical details to support and contextualize this central motivation.
3. Page 2, lines 94-100: The description of the raw materials requires additional details for reproducibility. The information provided (e.g. provenance from the germplasm bank, r. 96) is insufficient, lacking critical references to the year of harvest, storage conditions and maturity stage of the seeds, factors affecting the composition. What were the duration and conditions (temperature, humidity, etc.) of seed storage until extraction? Specifying these is crucial.
4. Page 3, lines 102-109: The extraction procedure you describe (ratio 1:10, 55°C, 2 minutes) uses an exceptionally short contact time for the isolation of bioactive compounds. Please specify whether this parameter has been optimized. Have you investigated the extractive yield as a function of time? A justification for this short duration is needed, given that similar protocols in the literature report significantly longer extraction times (30-60 minutes).
5. Page 3, Table 1: There is a linguistic inconsistency in the heading of Table 1: “% CMC, % Inulin, % Polydextrose.” I suggest replacing the term “Inulin” with its standard English form, “Inulin,” to ensure consistency throughout the document.
6. Page 4, lines 141-149: The enzymatic method for fiber determination is described in detail, which is a good thing. However, it is not clear whether and how the fiber intake from the transport supply (inulin and polydextrose) was taken into account in the calculation. Since you added 30% of these to the purchase (Table 1), how did you differentiate the native fiber of the pinhão seeds from the fiber added through the transporters?
7. Page 8, lines 306-311: Please clarify the experimental design: Were the three reported measurements technical replicates from a single powder batch, or the results of three independent spray-drying runs?
8. Page 10, line 358: The phrase "a positive aspect" is too vague. Please explain what the concrete benefit of high fiber content is in this specific context (e.g. for bioaccessibility, functional properties, nutritional value of the final product).
9. Page 14, lines 565-612: Multielement profile analysis provides valuable data, but its interpretation is incomplete without a nutritional context. To enhance its relevance, the section would benefit from a brief discussion comparing concentrations with dietary references and estimating intake at a realistic consumption level. To make the data more accessible, you can include a simple estimate.
10. The manuscript describes the properties well, but does not adequately discuss where these powders would actually be used. You mention “functional foods” repeatedly, but do not provide specific examples.I recommend adding a short paragraph that specifies concrete examples of use (e.g., product types, suggested concentrations) and connects the unique properties of each formula (E1, E2) to the specific advantages in chosen applications.
11. Page 16, lines 624-637: The conclusions provide a good summary of the findings, but do not suggest future research directions. Recommendation: To increase impact, you can add 1-2 sentences with concrete suggestions for further research. For example: “Future studies could analyze the stability of powders under different storage conditions and their functional behavior in specific food matrices, such as beverages or baked goods.”

 

 

 

 

 

 

Author Response

Dear Reviewer, thank you for your consideration. The responses are in the document. Please see the attachment. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

There few other comments need for improvement:

1. Abstract mentioned that "No detectable phenolic compounds were observed" but in the section 3.5 "The detection of individual phenolic compounds was confirmed". Why did the statement inconsistent? Please clarify.
2. The author stated that the spray drying could protect the phenolic compounds. The statement is overclaim because there is no proof. The authors did not conducted the quantification of phenolics before and after encapsulation. The initial concentration of phenolics is unknown, how the author knows that the spray drying could protect the phenolics? Spray drying process is operate at high temperature, it could cause a degradation of the compounds.
3. How does CMC help to improve product flow in the drying process? Any supporting evidence?
4. The equation should use proper symbol for the operations.
5. The format for list of reference is inconsistent. Some use abbreviation of the journal, some use full name of the journal.Please check.

Author Response

Reviewer 1: Comments and Suggestions for Authors

There few other comments need for improvement:

Abstract mentioned that "No detectable phenolic compounds were observed" but in the section 3.5 "The detection of individual phenolic compounds was confirmed". Why did the statement inconsistent? Please clarify.

R: Thank you for the comments. The sentence has been rewritten.

The author stated that the spray drying could protect the phenolic compounds. The statement is overclaim because there is no proof. The authors did not conducted the quantification of phenolics before and after encapsulation. The initial concentration of phenolics is unknown, how the author knows that the spray drying could protect the phenolics? Spray drying process is operate at high temperature, it could cause a degradation of the compounds.

R: Dear Reviewer, we agree, and this comment was addressed. For this reason, please check the introduction Line 85-90.

How does CMC help to improve product flow in the drying process? Any supporting evidence?

R: Thank you for the comment. CMC, although classified as a hydrocolloid, acts as a rheology-modifying agent when used at low concentrations, helping to stabilize the viscosity of the feed solution and promote the formation of more uniform droplets during atomization. This behavior reduces the tendency for particle collapse, premature agglomeration, and adhesion to internal surfaces, thereby facilitating the continuous movement of material inside the drying chamber. The literature reports that small amounts of hydrophilic polymers can improve the flow of atomized material and reduce wall deposition within the equipment, resulting in more efficient powder collection in the cyclone and lower product loss [23, 42]. The inclusion of CMC in the formulation therefore had a strictly technological purpose, supported by evidence showing that, at reduced levels, this hydrocolloid contributes to proper powder flow and, consequently, enhances the operational efficiency of the drying process.

The equation should use proper symbol for the operations.

R: Thank you for the comments, the equations have been revised to ensure that the symbols are properly displayed.

The format for list of reference is inconsistent. Some use abbreviation of the journal, some use full name of the journal.Please check.

R: We appreciate the observation. The reference list has been reviewed and standardized using a single format for journal names, as required by the journal. When available, we adopted the official abbreviation of the journal; in cases where no recognized abbreviation exists, we retained the full journal name.

Reviewer 3 Report

Comments and Suggestions for Authors

Accept in present form.

Author Response

Thank you, Dear reviewer. 

Reviewer 4 Report

Comments and Suggestions for Authors

    The authors have adequately addressed all the comments raised during the review process. The revised manuscript shows clear improvements in clarity, structure, and methodological detail. The abstract and introduction were revised to better reflect the results and the purpose of the study, while additional information regarding raw material characterization, extraction conditions, and experimental design improves reproducibility.
     The discussion has been strengthened by adding nutritional context to the mineral profile and by providing concrete examples of potential applications for the developed powders. The conclusions are consistent with the presented results and now include perspectives for future research.
     Overall, the manuscript is well revised and scientifically sound.

Author Response

Thank you, Dear reviewer.