Abstract
One environmental challenge posed by agricultural waste in the Philippines can be mitigated by converting fruit peel waste into valuable cellulose-derived microbeads. Utilizing the ionic gelation technique, this study introduces a sustainable, “waste-to-value” innovation designed to replace synthetic microplastics in the cosmetic industry. The resulting microbeads are characterized by a yellowish-green, spherical morphology with a standardized particle size of 850 micrometers, well within the functional limit for exfoliants, and an excellent flowability rating indicated by a 26.55° angle of repose. When incorporated into formulations, the microbeads maintained high structural stability; the resulting hand sanitizer had a pH of 3.55, while the facial gel exfoliant had a pH of 7.6, demonstrating excellent homogeneity and foam stability. By successfully validating these bio-based alternatives, the study highlights a circular-economy approach that mitigates food-processing waste while providing eco-friendly, high-performance materials for the global personal care sector.
Introduction
In terms of social inclusion, environmental contamination, and economic sustainability (Gupta et al., 2015; de Vitorino Souza Melaré et al., 2017), solid waste (SW) mismanagement is a global problem that calls for integrated evaluations and holistic measures (Bing et al., 2016). In developing and transitional nations, where unsustainable management of SW is prevalent, attention should be given (The World Bank, 2012). Fruit leftovers, which accumulate in agro-industrial yards with little commercial value, pose a significant environmental risk. Due to the high expense of transportation and the scarcity of landfill space, disposing of these wastes is costly. As a result, they are disposed of carelessly, raising concerns about environmental issues (Upadhyay et al., 2010). Furthermore, managing waste in developing nations is becoming increasingly complex as the daily production and processing of fruits and vegetables increase. This is because inappropriate waste material management encourages microbiological deterioration and environmental damage. However, the expenditures of drying, storing, shipping, and distributing byproducts are not economically feasible in developing nations (Varzakas et al., 2016; Arvanitoyannis and Varzakas, 2008). To achieve both sustainable development and economic progress, the Philippines must revise its waste management approaches, particularly regarding organic waste.
Despite the established potential of citrus-derived cellulose, a significant gap remains in the literature regarding the systematic optimization and functional performance of these microbeads within specific, high-demand cosmetic formulations.
Most contemporary research focuses predominantly on extraction yields and initial material characterization, often overlooking the beads’ structural integrity and stability when suspended in complex chemical environments, such as high-alcohol sanitizers or viscous surfactant-based gels. This research addresses the defect by providing a comprehensive, integrated evaluation that goes beyond mere synthesis to rigorously test functional parameters such as spreadability, extrudability, and long-term stability across two distinct cosmetic prototypes. By adopting a rigorous optimization framework similar to the recent advancements in sustainable waste-derived material optimization exemplified by Bani et al. (2025) in their study on multi-source agricultural residues, this study bridges the divide between waste valorization and standardized product development, ensuring that these biodegradable alternatives meet the rigorous physicochemical requirements of the global cosmetic industry (Bani et al., 2025).
This study aims to initiate a sustainable development approach by utilizing waste materials with considerable potential to create value-added products. In addition, this will serve as a pilot study to develop cosmetic products that may provide equal or even superior functionality to commercially available products.
Methods
This study aims to establish an initiative for sustainable development by utilizing waste materials with significant potential to produce value-added products. Furthermore, this will serve as a pilot study to formulate cosmetic products that may provide equal or even superior functionality to commercially available products.
The peels of the calamansi were subdivided into two parts: epicarp or albedo (colored peripheral surface) and mesocarp or albedo (white soft middle layer). The mesocarp or albedo is rich in polysaccharides such as pectin, hemicellulose, and cellulose, which were used to develop biodegradable microbeads.
This project would consist of the following:
Collection of calamansi peels
Separation of the albedo and avedo components manually.
Extraction of cellulose from the albedo component for the microbead production. The cellulose was extracted using alkaline treatment followed by bleaching. To obtain dry powders, the extracted cellulose was lyophilized.
Preparation of microbeads via ionic gelation. Dried microbeads were obtained and incorporated into the different cosmetic formulations. Before incorporation, the microbeads were evaluated for their physicochemical properties and stability to ensure proper shelf-life.
Formulation of cosmetics (facial gel exfoliant, hand sanitizer, and deep cleansing soap). Physicochemical properties of the different cosmetics were evaluated, including physical evaluation, pH determination, percentage of free alkali, foam height and retention, alcohol-insoluble matter, spreadability, extrudability, viscosity, irritability, washability, and foamability. After all baseline values are recorded, the formulations will undergo stability testing.
Collection of calamansi peels
The Calamansi peels were collected from the industries manufacturing Calamansi juice in the city, and a few samples were authenticated by the Quarantine Division of the Department of Agriculture, Zamboanga City. The peels were washed and dried to remove adhering liquid.
Extraction of cellulose
The cleaned calamansi peels were peeled, and the albedo portion was separated and cut into small pieces. These pieces were then dried in an oven at 50 °C for 48 h. This temperature serves as a “stress test” to identify immediate potential for phase separation, chemical oxidation of essential oils, or rapid microbial growth in the aqueous gel matrices. The dried sample was ground in a dry blender, and the resulting powder was sieved to the desired size. Cellulose extraction was performed using an alkaline treatment followed by bleaching (Zain et al., 2015).
A 50 g sample of dried albedo powder was weighed and transferred into a round-bottom flask. An alkaline solution (4% wt NaOH) was added, and the treatment was performed under reflux at 100–120 °C for 2 h. The obtained mixture was filtered and washed several times with distilled water to remove lignin and hemicellulose that had dissolved in the solution. The resultant fiber was dried before bleaching. Bleaching treatment was performed under reflux at 110–130 °C for 4 h after adding 60 g of fiber to 400 milliliters (mL) of each solution: 1.7% NaClO2, acetic buffer, and distilled water. The mixture was allowed to cool, then filtered and washed with distilled water until white cellulose was obtained. The cellulose obtained was dried by using a freeze dryer at −39 °C for 24 h. The powdered cellulose was stored in an air-tight container until further use.
Confirmatory test of cellulose
Iodine Test. Add a pinch of the cellulose powder to a watch glass. Add 2–3 drops of Lugol’s Iodine to the cellulose powder. A blue-black color was observed, which is indicative of the presence of polysaccharides.
Preparation of microbeads
The Ionotropic Gelation Technique was used to prepare cellulose microbeads from calamansi peels. A mixture of sodium alginate and carrageenan (60:40 w/w, 2% w/v) was dissolved in deionized water under magnetic stirring for ~30 min at 60 °C, then cooled to ~37 °C. An accurately weighed quantity of cellulose powder was added to the mixture, which was then thoroughly mixed with a magnetic stirrer at 400 rpm. For the formation of microbeads, 50 mL of this solution was extruded dropwise from a needle into 100 mL of 2% calcium chloride solution, and the mixture was stirred at 100 rpm for 10 min. The microbeads were separated from the hardening bath and suspended in a 2% w/v sodium alginate solution for coating. The coated microbeads were formed by taking the microbeads into a plastic pipette and dropping them into a hardening bath of calcium chloride concentration (1 mM) in water. A 1 mM concentration for the hardening bath was optimized to ensure adequate ionic crosslinking of the sodium alginate-coated cellulose without inducing excessive brittleness or “over-curing, “which can occur at higher concentrations. This specific molarity facilitates a controlled gelation rate, which is essential for maintaining the internal porous structure of the calamansi-derived cellulose (Lee and Mooney, 2012). After a few minutes of curing, the coated microbeads were removed from the hardening bath, washed with deionized water, and placed in petri dishes for “protection” and “conservation.” Finally, the coated microbeads will be dried (dehydrated) for 24 h at room temperature (Badarinath et al., 2010; Trif et al., 2019).
Characterization of microbeads
Their chemical functionalities and physical properties determine the performance of cellulose microbeads in specific applications. For characterization, the general appearance, morphology, particle size, flow properties, and stability studies will be determined. The methods are derived from Badarinath et al. (2010).
General appearance: The morphological characterization, which includes shape, color, presence or absence of odor, and surface texture of the microbeads, will be determined.
Morphology: The physical surface and morphology of the microbeads will be determined using a scanning electron microscope. Microbead samples will be sputtered with gold and scanned at an accelerating voltage of 15 Kv.
Particle size: Particle size distribution will be determined by sieve analysis on a mechanical sieve shaker using different meshes (12, 16, 20, and 30) per the American Society for Testing and Materials.
Flow properties: The angle of repose will be determined by the funnel method.
The microbeads will be allowed to ow through the funnel freely onto the surface. The cone’s diameter will be measured, and the angle of repose will be calculated using the equation. An angle of repose of 46 or above indicates poor flow properties.
where is angle of repose, h is height of the cone, r is radius of the cone base.
Stability test: A small number of biodegradable microbeads were placed in a hot-air oven at 45 °C for 8 weeks (60 days), with three time points (2nd, 4th, and 8th weeks). The bead size and form will be observed through the stability test.
Preparation of cosmetic products
Hand sanitizer
All ingredients will be added and stirred well into distilled water, except citronella oil, cinnamon oil, triethanolamine, alcohol, and perfume. Citronella oil and cinnamon oil will be added to triethanolamine along with perfume, then stirred well. Both prepared solutions will be mixed as the calamansi microbeads are slowly added. The volume will be made up using alcohol.
| Ingredients | Quantity taken (10 mL) |
|---|---|
| Citronella oil | 1 mL |
| Cinnamon oil | 1 mL |
| Carbopol 940 | 0.1 g |
| Triethanolamine | 0.1 g |
| Glycerine | 0.5 mL |
| Polysorbate-20 | 0.1 mL |
| Perfume | Qs |
| Methyl paraben | 0.1 mg |
| Ethyl alcohol | 4 mL |
| Distilled water | 2 mL |
| Calamansi microbeads | 5 g |
Evaluation of physicochemical parameters of the prepared hand sanitizer
Determination of clarity, color, and odor: Visual observation against a white background will be done for clarity and color of the prepared formulation, and the odor will be smelled.
pH: pH will be determined using a Digital pH Meter. The formulations will be dissolved in 100 mL of distilled water and stored in a desiccator for 2 h. The pH of the formulation will be measured with a previously calibrated pH meter.
High-temperature stability: A 1 g sample will be mixed with 5 mL of sterile water; 1 mL of sanitizer will be mixed with 5 mL of 0.5% DMSO. The prepared solutions will be allowed to stand at 50 °C for 1 week. The stability of the solutions will be observed during this period. The sample, which will behomogeneous after standing, will be considered stable; if it produces rough crystals or precipitates, it will be considered unstable.
Stability Test: 5 mL of sanitizer will be placed in a separate jar and heated in an oven at 45 °C for 8 weeks, with three intervals (2nd, 4th, and 8th weeks). This is based on the cosmetic stability policy that a sample stored at 45 °C for 8 weeks is equivalent to one stored at room temperature for a year. The accelerated stability protocol is a standard industry benchmark; it provides a predictive model in which 8 weeks of exposure are statistically equivalent to 1 year of shelf-life at room temperature, as per cosmetic stability guidelines (IFSCC). The physicochemical properties of each prepared cosmetic formulation will be tested again after the entire stability testing.
Facial gel exfoliant
All preservatives, propylene glycol, and sodium lauryl sulphate will be dissolved in a sufficient quantity of water. To the solution, Carbopol will be added slowly with constant stirring until a gel-like dispersion is obtained. Five grams of calamansi microbeads will be added slowly until a gel-like consistency is achieved. Then, finally, triethanolamine will be added.
| Ingredients | Quantity (%) |
|---|---|
| Carbopol 940 | 2 |
| Methyl paraben | 0.1 |
| Propyl paraben | 2 |
| Triethanolamine | 2 |
| Propylene glycol | 2 |
| Sodium lauryl sulphate | 2 |
| Distilled water | Q.S |
| Calamansi microbeads | 5 g |
Evaluation of physicochemical properties of facial gel exfoliant
A Physical evaluation: The prepared exfoliant will be visually inspected for homogeneity, color, and lumps after being placed in a clean, transparent container.
B pH: The pH of the gels will be determined using a digital pH meter.
C Spreadability: A small quantity of the sample will be placed on a glass slide, and another slide will be placed above it; 100 g of weight will be placed on the slide. The time taken for the gel to spread on the side will be noted and measured using the formula:
S = Spreadability; m = weight placed on the slide; l = length of the glass slide.; t = time taken in second
D Extrudability: A collapsible tube containing the formulation will be pressed firmly at the crimped end. After removing the cap, the average extrusion pressure was determined from the weight (in grams) required to extrude the formulation, and the time required to extrude the formulation was recorded.
E Irritability: A small amount of gel will be applied to the skin surface for a few minutes, and the skin will be checked for reactions.
F Washability: A small amount of gel will be applied to the skin surface, then washed off with running water.
G Foamability: A small amount of gel will be taken in a graduated cylinder, shaken for 5 min, and the foam stability of the gel will be measured.
H High-temperature stability: A 1 g sample will be mixed with 5 mL of sterile water; 1 mL of sanitizer will be mixed with 5 mL of 0.5% DMSO. The prepared solutions will be allowed to stand at 50 °C for 1 week. The stability of the solutions will be observed during this period. The sample, which will be homogeneous after standing, will be considered stable; if it produces rough crystals or precipitates, it will be considered unstable.
I Stability test: 5 mL of facial gel exfoliant will be placed in a separate jar and heated in an oven at 45 °C for 8 weeks, with three intervals (2nd, 4th, and 8th weeks). This is based on the cosmetic stability policy that a sample stored at 45 °C for 8 weeks is equivalent to one stored at room temperature for a year. The physicochemical properties of the prepared cosmetic formulations will be tested again after the entire stability testing (Table 1).
Table 1
| Process storage | Parameter | Value/setting | Rationale |
|---|---|---|---|
| Cellulose extraction | Oven drying | 50 °C for 48 h | Removal of moisture without degrading fibers |
| Cellulose extraction | Alkaline treatment | 4% NaOH @ 100–120 °C | Solubilization of lignin and hemicellulose |
| Bead formation | Hardening bath | 1 mM CaCl2 | Optimal ionic gelation and structure integrity |
| Bead preparation | Dehydration | 24 h (room temp) | Preservation of spherical morphology |
| Stability testing | Accelerated study | 45 °C for 8 weeks | Predictive of 12-month shelf life |
| Characterization | Target particle size | 850 μm (Sieve #20) | Standardized cosmetic exfoliation range |
Summary of key process parameters.
Results
Calamansi microbeads
General appearance
Figure 1 Illustrates the macro-appearance of the successfully synthesized biodegradable microbeads.
Figure 1
Morphology
Figure 2 provides a microscopic view of the beads at 50×, 100×, 400×, and 800× magnifications.
Figure 2
Particle size
The calamansi particle size was measured at 850 micrometers using sieve number 20. The calamansi microbeads show the standard size of not surpassing 1,000 micrometers (Belyaeva et al., 2004).
Flowability test
Particle repose angle determines a particle’s flowability (Kunii and Levenspiel, 1991). One significant intrinsic feature of powder rheology is the angle of repose (Yang, 2003). The calamansi microbeads’ reaction angle of 26.55° denotes an excellent or free-flowing group in the flowability classification (Carr, 1965; Yang, 2003).
Stability test
The microbeads were consistently stable throughout the period. Hence, results from the stability studies indicated that microbeads were physically and chemically stable for more than 60 days, exhibiting no significant change in bead size and physical form.
Hand sanitizer
In the present study, the formulated hand sanitizer was evaluated under various parameters, as shown in Table 2. An attempt was made to create a hand sanitizer using alternative ingredients. The formulated product was smooth in texture, clear, crystal white in color, and gel-like in consistency. It also had a sweet or aromatic smell (see Figure 3). A digital pH meter was used to measure the pH of the hand sanitizer gels. The purpose of the investigation was to determine whether specific prepared formulations could be neutralized. To prevent skin irritation and inflammation, the optimal pH range for a topical dose form is between 4.0 and 7.0, which is the wide range of the skin’s pH15. With an average pH of 3.55, the pH readings.
Table 2
| Sr. No. | Parameter | Evaluation |
|---|---|---|
| 1 | Color | Crystal white |
| 2 | Odor | Sweet or aromatic |
| 3 | Clarity | Clear, no particulate matter |
| 4 | pH | 3.55 ± 0.2 |
| 5 | High temperature stability | Stable, no change in the formulation |
| 6 | Stability test | Stable, no change in the formulation |
Evaluation parameter of calamansi microbeads hand sanitizer.
Figure 3
in Table 2 indicated that the created formulation was slightly acidic. This might be due to the large portion of calamansi microbeads. According to reports, the neutral pH range is ideal for the growth of several harmful bacteria that can infect the skin.
On the other hand, if the pH level is somewhat acidic, normal ora is more likely to settle in the skin (Ali and Yosipovitch, 2013). Notably, an acidic pH environment (4.0–4.5) can facilitate attachment of normal ora to the skin (Lambers et al., 2006). Furthermore, it has been shown that the natural state of the skin’s surface has an average pH below 5.0, which is ideal for several critical dermal biological processes, including the formation of the lipid barrier and the homeostasis of the stratum corneum (Rippke et al., 2002; Parra and Paye, 2003).
Finally, the prepared hand sanitizer did not exhibit any color change or phase separation throughout the stability testing. Additionally, the products’ odors remained steady, and even after being heated during storage, their composition remained the same. This is because Carbopol 940, when used as a gelling agent has stable qualities that allow the resulting gel preparation to have good stability over time in storage (Astuti et al., 2017). Compared to hand sanitizer formulations, alcohol-based gel hand sanitizer is of high quality, extremely effective, and safer to use. Prepared gel hand sanitizers significantly improve hand hygiene and reduce the spread of bacteria among populations. We can use this hand sanitizer properly to maintain proper hand hygiene in the future. Furthermore, all the herbal plants used to make the hand sanitizer, and the blend of all extracts, had vigorous antibacterial activity against E. coli and P. aeruginosa. Coli, Klebsiella species, and S. aureus, S. The zones of inhibition for P. pyogenes and Dermatophyte were 7 ± 0.03, 7 ± 0.03, 8 ± 0.001, 7 ± 0.03, 6 ± 0.02, and 6 ± 0.01, respectively, 21. Ultimately, using naturally derived herbal hand sanitizers can be a viable substitute for chemically manufactured hand sanitizers that contain active silver nitrates. This is because people who prefer natural products might prefer herbal hand sanitizers, which are typically more affordable, effective, and environmentally friendly (Verma et al., 2023).
Facial gel exfoliant
The prepared facial gel exfoliant was evaluated for homogeneity, appearance, pH, spreadability, extrudability, irritability, washability, and foamability, and subjected to stability testing shown in Table 3. The formulated product was determined to be white, homogeneous, and free of lumps (see Figure 4).
Table 3
| Sr. No. | Parameter | Evaluation |
|---|---|---|
| 1 | Homogeneity | Homogenous |
| 2 | Color | White |
| 3 | Presence of lumps | Minimal |
| 4 | pH | 7.6 ± 0.165 |
| 5 | Spreadability | 103.80 g/s ± 12.898 |
| 6 | Extrudability | 17.27 g/s ± 1.026 |
| 7 | Irritability | Not irritable |
| 8 | Washability | 29 s ± 2.00 |
| 9 | Foamability | Stable |
| 10 | High temperature stability | Stable, no change in the formulation |
| 11 | Stability test | Stable, no change in the formulation |
Evaluation parameter of calamansi microbeads facial gel exfoliant.
Figure 4
Using a digital pH meter, the gel’s pH was measured at 7.6. After applying a small amount of gel to one glass slide and placing another on top, 100 g of weight was added to the slide, and the time required for the gel to spread and the area measured were recorded. The area and quantity of gel on the glass slide indicate a spreadability efficiency of 103.80 g/s ± 12.898. Additionally, a small amount of gel was added to a collapsible tube, and the crimped end was tightly crimped. Following the removal of the cap, the average extrusion pressure was calculated from the weight (17.27 g/s ± 1.026) needed to extrude, the extrusion time, and the amount of gel extruded. Following the skin irritation test, the gel was determined to be non-irritating after the same quantity was applied to the skin and left for a short while. This indicates that the microbeads found in the product are a non-irritating ingredient according to clinical practice guidelines of the Japanese dermatological association (Katoh et al., 2019; Omichi et al., 2014). After applying a little amount of gel to the skin, it was rinsed with water. It was simple to wash at 29 ± 2.00 s. In addition, the foam remained stable when a small quantity of gel was shaken with water in a graduated measuring cylinder. Ultimately, after going through two independent stability tests, the created facial gel exfoliant demonstrated good stability. The manufactured herbal scrub was deemed satisfactory for skin application to promote healthy, glowing skin following rigorous examination of numerous parameters. The use of scrub gel, which enhances oxygen delivery to the entire skin surface, helps promote blood circulation. After using a scrub, the skin feels cleaner, softer, and more invigorated. Investigation also found that the polyherbal scrub gel performed well and remained stable at 45 °C. Scrub gel’s results indicate that it can be used on the skin to enhance health and brightness without any adverse effects. Among the numerous formulas tested, the F9 batch produced good results, with a good pH and viscosity, as well as improved skin-smoothing and spreading capabilities (Aglawe et al., 2019). Thus, it can be said that this scrub gel has fewer adverse effects and is highly helpful for oily skin types. In conclusion, the scrub gel was assessed against a range of criteria and found suitable for use on the skin to promote health and radiance without causing adverse reactions. It is intended to conduct in vivo experiments on the irritancy of the prepared scrub (Aglawe et al., 2019).
Discussion
The practical synthesis and optimization of microbeads from calamansi (Citrus microcarpa) peels signify a notable progress in waste valorization, connecting this study’s findings with the “Circular Economy” concepts (Bani et al., 2025). The results validate the viability of using agricultural byproducts as raw materials; however, the efficacy of these beads is fundamentally based on polymer physics and formulation chemistry. The FE-SEM study (Figure 2) revealed a spherical, yet rough-textured, surface. However, this is a physical observation; the scientific interpretation is that the 1 mM concentration promoted a regulated, gradual rate of gelation. The reduced ionic concentrations facilitate more uniform crosslinking throughout the bead matrix, rather than the immediate formation of a dense outer layer. The interior porosity likely resulted in minor surface imperfections upon drying as the aqueous core constricted, a characteristic that may functionally improve the “mechanical grip” of the beads during exfoliation compared to flawlessly smooth synthetic polyethylene counterparts. The angle of repose (26.55°) indicates “Excellent” flow, affirming that the beads possess the necessary kinetic properties for automated industrial filling equipment, notwithstanding surface roughness (Kuo and Ma, 2001). The physicochemical stability demonstrated in both the hand sanitizer (pH 3.55) and the facial gel (pH 7.6) further exemplifies the adaptability of the cellulose-alginate matrix. The beads’ capacity to maintain integrity at 50 °C for 1 week demonstrates that the ionic “egg-box” bonds are sufficiently resilient to withstand high-energy conditions without dissociating 28. The facial gel formulation exhibits spreadability of 103.80 g/s and extrudability of 17.27 g/s, indicating a product that offers minimal resistance to the user while retaining sufficient yield stress to ensure homogeneous bead suspension. The remarkable uniformity indicates that the calamansi cellulose fibers form a supplementary structural network within the gel, thereby inhibiting sedimentation, a phenomenon frequently observed in inadequately designed natural formulations. The stability results at 45 °C for 8 weeks are significant; this performance indicates a 12-month shelf life under ambient conditions, implying that residual natural antioxidants in the citrus fibers may offer some self-preservation against oxidative degradation (International Federation of Societies of Cosmetic Chemists, 1992).
Conclusion
This work demonstrates that cellulose derived from calamansi peel can be converted into functional, biodegradable microbeads with defined dimensions (850 μm) that meet essential performance criteria for cosmetic applications. Nonetheless, these findings offer strong proof of concept, but the shift from laboratory-scale synthesis to industrial production must be undertaken with prudence. Assertions about industrial scalability and market preparedness require additional verification, especially regarding long-term dermatological safety, via clinical patch testing to assess the effects of residual citrus oils on sensitive skin. Moreover, full market entry depends on rigorous adherence to international regulations, including the ASEAN Cosmetic Directive, which governs microbiological thresholds and heavy metal residues. Future studies must concentrate on determining the exact rate of environmental degradation across diverse habitats to validate “eco-friendly” assertions. This approach connects waste utilization with standardized product creation, although industrial implementation relies on thorough safety profiling and stringent regulatory approval.
Statements
Data availability statement
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.
Author contributions
RF: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing. FM: Methodology, Project administration, Conceptualization, Funding acquisition, Writing – original draft. NM: Methodology, Validation, Investigation, Funding acquisition, Writing – original draft.
Funding
The author(s) declared that financial support was received for this work and/or its publication. This research was funded by the Department of Science and Technology—The Philippine Council for Health Research and Development (DOST-PCHRD).
Acknowledgments
Thanks to Mr. and Mrs. Ernesto Hau of Zamboanga Tropical Foods for providing the needed calamansi peels and for supporting the completion of this research study. I would also like to thank the two reviewers for their constructive comments and suggestions.
Conflict of interest
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Generative AI statement
The author(s) declared that Generative AI was used in the creation of this manuscript. Generative AI was used Google gemini Quillbot.
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Summary
Keywords
calamansi peel, cellulose microbeads, cosmetic formulation, sustainable innovation, waste utilization and management
Citation
Fernandez RA, Mariano F and Mabalot NJ (2026) Waste utilization and optimization of calamansi peels: a formulation study on biodegradable microbeads. Front. Sustain. Food Syst. 10:1762782. doi: 10.3389/fsufs.2026.1762782
Received
08 December 2025
Revised
24 January 2026
Accepted
26 January 2026
Published
16 February 2026
Volume
10 - 2026
Edited by
Abhishek Agarwal, Royal University of Bhutan, Bhutan
Reviewed by
P. SInha, University of South Africa, South Africa
Rakesh Malviya, Delhi Technological University, India
Updates
Copyright
© 2026 Fernandez, Mariano and Mabalot.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Rusell Alen Fernandez, rusellalen.fernandez@uz.edu.ph
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.