Review Reports - Potential of Pigmented Rice in Bread, Bakery Products, and Snacks: A Narrative Review of Current Technological and Nutritional Developments

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

COMMENTS FOR SCIENTIFIC ARTICLE

It would be appropriate to include or at least discuss the effect of parboiling on pigmented rice, considering its potential positive impact on both nutritional properties (e.g. antioxidants, γ-aminobutyric acid “GABA”, resistant starch) and technological properties (e.g. viscosity, structure of the finished product).

A comparison between raw and parboiled pigmented rice, possibly combined with other treatments (e.g. extrusion, fermentation), could offer relevant results for the food industry. Parboiling has been shown to increase the content of GABA and resistant starch, with potential benefits on glycaemic index and antioxidant capacity.

Nutritional aspects

- Migration of water-soluble vitamins (e.g. B1, B3) and phenolic compounds to the endosperm → increased retention after refining.

- Potential increase in resistant starch → reduction of the glycaemic index.

- Possible improved bioavailability of GABA and antioxidants.

Technological effects

- Increased grain integrity → useful for pasta, noodles and snacks.

- Change in rheological properties of flour → impact on viscosity, water absorption, gelatinisation.

- Potential synergy with other treatments (e.g. parboiling + extrusion or fermentation).

Sensory and functional characteristics

- Improved texture and chewability.

- Reduction of friability in gluten-free bakery products.

- Possible positive impact on shelf-life and colour stability.

It would also be useful to include a discussion on the impact of advanced milling techniques, such as micronisation and air-classification, in the nutritional enhancement of pigmented rice. These processes reduce particle size and increase surface area, thus improving the bioavailability of bioactive compounds and enabling the production of enriched functional flours, with targeted applications in baked goods and snacks.

The manuscript would benefit from a section on the shelf-life of pigmented rice products. It would be useful to discuss the stability of bioactive compounds (e.g. anthocyanins, GABA), sensory properties (colour, texture) and microbiological safety over time. Furthermore, the influence of technological treatments (e.g. extrusion, germination, micronisation) on shelf-life would deserve attention, also with a view to industrial development.

The results section, although rich in references, is descriptive and qualitative. To strengthen the scientific impact of the manuscript, it would be desirable to include a quantitative summary of the available data (e.g. comparative tables, graphs). No confidence intervals, standard deviations or statistical significance of the results are given. This significantly limits the strength of the analytical conclusions and makes it difficult to identify consistent or reliable trends.

Author Response

see attached file

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The topic aligns well with the scope of Applied Sciences, particularly within the Food Science and Technology section. The manuscript offers a comprehensive overview of the technological and nutritional applications of pigmented rice in baked goods and snacks, bringing together relevant and up-to-date evidence. Despite the solid content, several technical aspects require improvement or standardization:

The manuscript lacks some essential components or addresses them insufficiently. The authors did not clearly describe the methodology used to conduct the review. They should first clarify in the objectives what type of review is being presented (e.g., scoping, meta-analysis, or systematic review). Although databases and search terms were mentioned, details regarding inclusion and exclusion criteria, the full data collection period, the number of studies included, and whether any systematic approach (e.g., PRISMA) was employed are missing.
The authors are encouraged to emphasize the limitations of the reviewed studies and highlight the technological barriers that hinder large-scale industrial application of pigmented rice.
The discussion should be more critical. Some results are presented in a purely descriptive manner, without in-depth interpretation of why certain effects occur—for example, the reduction in viscosity observed in cakes made with black rice.
There is a lack of direct comparisons between cultivars (e.g., red vs. black rice) in terms of technological and functional performance.
It is recommended to expand the explanation of how phenols, anthocyanins, and other bioactive compounds interact with gluten structures and the starch matrix. Including conceptual diagrams or schematics would be beneficial.
The authors should address industrial-scale challenges, such as pigment stability, product shelf life, and food regulations related to the labeling of functional ingredients.
A subsection on economic aspects or market acceptability is recommended. A discussion on the marketability and global consumer acceptance of pigmented rice-based products would significantly enrich the manuscript.

Author Response

see attached file

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript “Potential of Pigmented Rice in Bread, Bakery Products and Snacks: A Review of Current Technological and Nutritional Developments” presents an important review of pigmented rice, highlighting its numerous nutritional and other advantages in various food applications compared to non-pigmented rice. It is a valuable contribution to the dissemination of knowledge about a lesser-known food, supporting the improvement of processing techniques and, consequently, encouraging broader consumer adoption.

I suggest that some of these discussions be included in the review:

Considering that pigmented rice production represents only 0.1% of total global rice production, what strategies do the authors recommend to increase the production and commercialization of these varieties?
What are the main agronomic challenges in increasing the yield of pigmented rice compared to polished white rice?
What measures could be taken to promote pigmented rice as a functional food in international markets?
What are the key technological challenges in incorporating pigmented rice into products such as bread and pasta, especially considering its differences from white rice?
Why did the authors choose to exclude studies that used bran or extracts of pigmented rice, focusing solely on the whole grain?
Given that the amylose/amylopectin ratio is variety-dependent and influences the glycaemic index, could pigmented rice be a viable strategy for developing low-glycaemic-index foods targeted at people with diabetes?
Is there a strong enough correlation between the phenolic profile and the visual color of the grain for the latter to serve as a reliable marker?
Have combinations of pigmented rice with other flours (e.g., cassava, wheat, corn) been tested to compensate for its lower viscosity or to modify its retrogradation profile?
Parboiling, for example, alters texture and increases digestibility. How might these transformations influence the sensory acceptance of pigmented rice-derived products among different consumer groups (e.g., children, athletes)?
What microorganisms were used in the fermentation processes mentioned? Could different microorganisms affect the phenolic and sensory profiles of fermented pigmented rice in distinct ways?
As this is a review paper, I suggest that the selected references be more up-to-date, as more than half of them are from before 2020.

Author Response

see attached file

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I recommend including a discussion on air classification, a technique that, when integrated with micronization, enables the selective separation of particle fractions based on their physicochemical characteristics. This combined approach can be strategically employed to tailor ingredient functionality in accordance with the specific requirements of the intended final product. Incorporating this aspect would enhance the comprehensiveness of the technological perspective presented in the manuscript.

Author Response

Additional statement was added to further stress potential of micronization and air classification.

Page 11, lines 467-479

Air classification can be performed independently or in combination with the micronization technique, further enhancing the physicochemical and nutritional properties of cereal grains. Spaggiari et al. [61] studied the effects of air classification, both with and without micronization, on the lipid components of brown rice bran. Their findings revealed that total crude fat content was higher in the fine air-classified fractions, with polyunsaturated triacylglycerols being the most abundant while the concentration of monoacylglycerols increased in the fine fractions. Given the emulsifying properties of these compounds, this approach could be advantageous for the development of rice-based products. Combining micronization with air classification has shown promising effects on whole-grain brown rice and could potentially be applied to pigmented rice. However, to date, no studies have specifically examined the use of micronization, with or without air classification, to enhance the physicochemical and nutritional qualities of pigmented rice for product development, leaving this topic open for further investigation and discussion.