Phytochemical Profiling and Characterization of Honeydew, Cantaloupe, and Galia Melon Peel Extracts for Potential Prebiotic Activities

TL;DR

This study shows that melon peels contain bioactive compounds that can support the growth of beneficial gut bacteria, making them a potential source for prebiotic foods.

Contribution

The study introduces melon peels as a novel and sustainable source of prebiotic-like compounds with high non-digestible polysaccharides and polyphenols.

Findings

Cantaloupe peel had the highest non-digestible polysaccharides and enhanced probiotic growth significantly.

Melon peels showed high polyphenol content, with cantaloupe having the highest at 175 mg/100 g.

FTIR and NMR analyses confirmed the presence of bioactive compounds like polysaccharides and polyphenols.

Abstract

This study characterized the peel extracts of
Cucumis melo
L. varieties and evaluated their in vitro prebiotic‐like activity supporting the growth of
Lactobacillus delbrueckii
subsp. bulgaricus and
Bifidobacterium bifidum
. Melon peel extracts were prepared and freeze‐dried for analyzing sugar composition, enzymatic digestibility, and probiotic stimulation in various sample extracts. Among the tested varieties, cantaloupe peel exhibited the highest concentration of non‐digestible polysaccharides (29.20 ± 1.0 mg/g) and significantly enhanced
L. delbrueckii
and
B. bifidum
growth to 9.81 ± 0.04 and 9.79 ± 0.01 log CFU/g. Total polyphenol content was greatest in cantaloupe (175 mg/100 g), followed by galia (173 mg/100 g) and honeydew (121 mg/100 g). FTIR and 1H‐NMR analyses showed the presence of polysaccharides, sugars, polyphenols, and other bioactive functional groups. Hydrolysis resistance to acid and α‐amylase was 9.52% and 34.67% for cantaloupe, and 6.12% and 30.65% for honeydew, respectively. Overall, melon peel extracts demonstrated substantial prebiotic‐like activity, attributed to their high levels of non‐digestible polysaccharides, reducing sugars, phenolic compounds. These findings identify melon peel as a promising, sustainable source of bioactive ingredients for gut health promoting functional foods.

Bioactive compounds are recovered from Honeydew, Cantaloupe, and Galia melon peels through aqueous and ethanolic extraction followed by freeze‐drying. The resulting extracts undergo comprehensive characterization using HPLC, FTIR, and NMR spectroscopy to define their chemical profiles. Ultimately, the study evaluates these extracts for their antioxidant activity and inhibitory effects against enzymes like $\alpha$‐amylase.

Figures

Quantification of Sugars by HPLC (A) Sugar standards, (B) Melon peel extracts: Honeydew melon peel extract (HMPE), Cantaloupe melon peel extract (CMPE), Galia melon peel extract (GMPE).

HPLC chromatogram of phenolic compounds in melon peel extracts for Honeydew, Cantaloupe, and Galia melon peel at 280 nm. Peak (1) Flavone, (2) 4‐hydroxybenzoic acid, (3) Apigenin‐7‐glycoside, (4) Oleuropein, (5) p‐coumaric acid, (6) Gallic acid, (7) Hydroxytyrosol, (8) Chlorogenic acid, (9) Vanillic acid, (10) Protocatechuic acid, (11) Caffeic acid, (12) Pinoresinol, (13) Naringenin.

Hydrolysis rate in percentage (±SD) of honeydew, cantaloupe, and galia melon peel extracts (A) Simulated gastric buffer (B) α‐amylase. Different letters indicate significant differences (Tukey's HSD, p < 0.05).

FTIR Spectra of Different Varieties of Melon Peels.

1H‐NMR spectrum of melon peel. (A) Honeydew melon peel: 1: Sucrose, 2: Fructose, 3: Glucose, 4: Pectin, 5: Malic acid, 6: Succinic acid, 7: β‐glucose, 8: Citric acid, 9: Chlorogenic acid, 10: Caffeic acid. (B) Cantaloupe melon peel: 1: Sucrose, 2: Fructose, 3: Glucose, 4: α‐xylose, 5: Chlorogenic acid, 6: Alcohol, 7: Glutamate, 8: Acetic acid, 9: Citric acid, 10: Quercetin. (C) Galia melon peel: 1: Sucrose, 2: Fructose, 3: Glucose, 4: Galacturonic acid, 5: Xylans, 6: Glutamine, 7: Chlorogenic acid, 8: Malic acid, 9: Esters.

Tables

TABLE 1. Growth of probiotic bacteria in MRS broth supplemented with melon peel extract.

Sample	Lactobacilli bulgaricus microbial count (log CFU/g dry extract)			Bifidobacterium bifidum microbial count (log CFU/g dry extract)
Treatment	0 h	24 h	48 h	0 h	24 h	48 h
To	6.52 ± 0.00c	9.21 ± 0.02d	9.18 ± 0.01c	6.47 ± 0.01b	9.52 ± 0.02b	9.60 ± 0.01c
HMPE	6.99 ± 0.01a	9.34 ± 0.04b	9.76 ± 0.03ab	6.89 ± 0.02a	9.45 ± 0.01c	9.97 ± 0.02a
CMPE	6.63 ± 0.01b	9.95 ± 0.02a	9.81 ± 0.04a	6.42 ± 0.00c	9.48 ± 0.03bc	9.79 ± 0.01b
GMPE	6.49 ± 0.03c	9.29 ± 0.05c	9.71 ± 0.04b	6.39 ± 0.00d	9.66 ± 0.01a	9.76 ± 0.02b

TABLE 2. Quantification of monosaccharide content in melon peel extracts.

Sample	Measured glucose concentration (mg/g dry extract)	Measured fructose concentration (mg/g dry extract)	Sum of reducing sugars (mg/g dry extract)	Recovery (%)
HMPE	152.13 ± 2.08b	213.41 ± 1.15b	365 ± 2.51b	99.6
CMPE	217.25 ± 0.57a	221.29 ± 1.01a	438 ± 3.01a	98.0
GMPE	140.11 ± 0.57c	198.43 ± 1.15c	338 ± 1.15c	97.5

TABLE 3. The non‐digestible polysaccharide content of melon peel extracts.

Sample	Non‐digestible polysaccharides acid enzyme digestion (mg/g dry extract)	Non‐digestible polysaccharides H2SO4 digestion/oligosaccharides (mg/g dry extract)	Non‐starch polysaccharides (mg/g dry extract)
HMPE	211.8 ± 58.2a	16.48 ± 3.24b	192.92 ± 3.05a
CMPE	208.4 ± 52.0b	29.20 ± 1.00a	178.62 ± 1.11b
GMPR	201.5 ± 37c	16.77 ± 4.02b	184.06 ± 0.76c

TABLE 4. Total phenolic content and antioxidant activity of peel extracts.

Sample	Phenolic assay	Antioxidants activity
	TPC (mg GAE/g)	DPPH (mg TE/g)	ABTS (mg TE/g)
HMPE	28.12 ± 2.13a	47.71 ± 3.02a	36.50 ± 3.23a
CMPE	29.35 ± 3.21a	51.72 ± 5.43a	37.57 ± 3.07a
GMPE	24.33 ± 0.55a	40.32 ± 5.69a	22.07 ± 1.05b

Full text

Introduction

1

Melon ( Cucumis melo L.) is extensively cultivated around the world and contributes significantly to global fruit production, with an annual yield of approximately 28 million metric tons (FAO 2022). Melon processing produces about 8–20 million metric tons of bio‐waste from its seed and peel. Melon peel is a rich reservoir of bioactive compounds, including polyphenols, dietary fiber, and oligosaccharides, yet remains underutilized. Its valorization into functional ingredients not only reduces environmental burdens but also enhances the economic sustainability of fruit processing (dos Santos et al. 2025; Tahir et al. 2024).

Melon peel is particularly rich in dietary fiber (lignin, hemicellulose, and cellulose), which acts as a fermentable substrate for beneficial gut microbes such as Lactobacillus and Bifidobacterium. Their selective fermentation leads to the production of short‐chain fatty acids (SCFA), thereby contributing to antioxidant, anti‐inflammatory, anti‐diabetic, and cardioprotective effects (Mallek‐Ayadi et al. 2017; Baz et al. 2024). These fiber fractions fulfill the criteria of prebiotics, which the International Scientific Association for Probiotics and Prebiotics (ISAPP) defined as “a substrate that is selectively utilized by host microflora to confer health benefits” (Bevilacqua et al. 2024; Ali et al. 2024). They are typically non‐digestible food components, including polysaccharides, polyphenols, and flavonoids, which exhibit antioxidant and immunomodulatory, and gut‐microbiota‐modulating properties. These include galacto‐oligosaccharides (GOS), isomalto‐oligosaccharides, fructo‐oligosaccharides (FOS), inulin, lactulose, and related compounds, which resist digestion in the upper gastrointestinal tract and are fermented by probiotic bacteria in the colon (Markowiak and Śliżewska 2017; Tuyen et al. 2025). Fermentation yields short‐chain fatty acids (SCFA), notably acetate, butyrate, and propionate, which lower intestinal pH, improve barrier function, regulate immune response, and maintain lipid and glucose homeostasis. SCFA also acts as a primary energy substrate for colonocytes and can cross the blood–brain barrier, where they exert systemic effects, including neurocognitive and anti‐inflammatory activity (Kovacs et al. 2025). Along with dietary fiber, melon peel possesses polyphenols, carotenoids, flavonoids, and essential fatty acids (linoleic, oleic, palmitic, α‐linolenic), exhibiting strong antioxidant, anti‐inflammatory, and cardioprotective activities (Khawaja et al. 2025). This underutilized fraction of the fruit contains significantly higher levels of minerals and bioactive compounds compared to the edible pulp, with potassium, calcium, sodium, and magnesium being predominant minerals (Silva et al. 2020). Notably, melon peel also provides considerable protein (21%), and essential amino acids such as isoleucine, histidine, leucine, methionine, and lysine, making it a nutritionally valuable by‐product (Abraham et al. 2025; Luecha et al. 2024). Evidence reported the prebiotic potential of melon peel flour through in vitro gastrointestinal digestion and fermentation, demonstrating enhanced SCFA production and probiotic growth (Gómez‐García, Vilas‐Boas, et al. 2022; AlMasoud et al. 2024). The optimization of pectin extraction from melon peel has identified its role as a promising source of prebiotic oligosaccharides (Bilraheem et al. 2024; Kunu et al. 2025). However, these investigations were restricted to single cultivar or isolated components, providing only a partial understanding of melon peel functionality. Therefore, the present study provides the comprehensive characterization of the phytochemical composition and prebiotic‐like potential of honeydew, cantaloupe, and galia melon peels. Extracts were prepared using solvent mix to maximize the extraction of potential bioactive compounds from peel waste of indigenous melon varieties (Cucumis melo, L. inodorus, Cucumis melo var. cantalupensis, and * Cucumis melo var. reticulatus*). Further, phenolics and antioxidant profiling of peel extracts was integrating advanced analytical techniques (HPLC and NMR) and structural analysis with in vitro probiotic assays. Study was aimed to generate novel insights about the valorization of melon peel extracts as a sustainable functional food ingredient with potential health benefits.

Materials and Methods

2

Reagents

2.1

Melons, including honeydew melon (* Cucumis melo L. inodorus*), cantaloupe melon (* Cucumis melo var. cantalupensis*), and galia melon (* Cucumis melo var. reticulatus*), were procured from Ayub Agricultural Research Institute (AARI, Faisalabad, Pakistan). Bile salts and α‐amylase ( Bacillus licheniformis ), disodium hydrogen phosphate, sodium dihydrogen phosphate, potassium sodium tartrate tetrahydrate, potassium chloride, sodium hydroxide pellets, sodium chloride, sodium carbonate, potassium persulfate, phenol (5%), 3,5‐dinitrosalicylic acid (DNS), Folin–Ciocalteu reagent, 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS) diammonium salt, Trolox (≥ 97%), buffered peptone water (BPW), D‐glucose, D‐fructose, L‐ascorbic acid, sucrose standards, and ethanol (95% and 50%) were also purchased from Merck KGaA (Darmstadt, Hesse, Germany). HPLC standards, ammonium acetate, sulfuric acid (95%–97%), potassium dihydrogen phosphate, De Man Rogosa and Sharpe agar, MRS broth, and hydrochloric acid (35%) were also purchased from Sigma‐Aldrich (St. Louis, MO, USA).

Methods

3

Preparation of Bioactive‐Rich Extracts

3.1

The extraction was conducted following the method described by Wichienchot et al. (2011) with slight modifications reported by (Panya et al. 2024). Initially, the melon peel was thoroughly washed, and then all pulp and seeds were removed. The cleaned peel samples were then homogenized into a fine paste using a domestic blender (Panasonic MX‐898 M‐LW, Panasonic Manufacturing, Johor Bahru, Malaysia) at 5000 rpm for 1 minute. To extract polysaccharides, a combination of solvents (aqueous and organic) was employed under varying time and temperature conditions. A sample‐to‐solvent ratio of 1:2 was found to yield optimal extraction efficiency, enhancing the recovery of bioactive compounds. The melon peel paste slurry was divided into four fractions for extraction. In the first fraction, ethanol (95%) was poured until it covered the peel completely. This mixture was incubated for 72 h at 38°C, followed by filtration through muslin cloth. The second fraction was treated with 50% ethanol and allowed to extract for 72 h under the same conditions. The third fraction was extracted with cold distilled water at ambient temperature for 4 h, and the fourth with boiling distilled water for 15 min at 100°C, respectively. The obtained extracts were combined and then concentrated using a rotary evaporator (N‐N Series A‐3S; Tokyo Rikakikai Co. Ltd., Tokyo, Japan) at 3000 Pa and 60 rpm. The concentrated extract was subsequently freeze‐dried using a lyophilizer (Christ, Alpha 1–4 LD plus, Martin Christ GmbH, Osterode am Harz, Lower Saxony, Germany) for 48 h at −41°C and 9 Pa and stored in dark glass bottles wrapped in aluminum foil, at −20°C until further analysis to preserve their stability and prevent light‐induced degradation.

Probiotic Growth Assay

3.2

The probiotic strains Lactobacillus delbrueckii subsp. bulgaricus and Bifidobacterium bifidum (ATCC 29521) were obtained from the National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre (NARC, Islamabad, Pakistan). The effect of melon peel extracts on probiotic growth was evaluated by following the standard method reported by Wichienchot et al. (2011), to evaluate the prebiotic‐like effect of plant‐derived oligosaccharides using MRS broth. The control medium contained no added oligosaccharide extract, whereas the test medium was supplemented with melon peel‐derived oligosaccharide extract as a substrate. L. delbrueckii subsp. bulgaricus and B. bifidum cultures were rehydrated in MRS broth and incubated for 24 h at 37°C before use. The culture was standardized to an optical density of 10^7^–10^8^ CFU/mL and used at a final concentration of 1% (v/v) in the growth medium. A total of 10 mL of media was prepared with 2 mg/mL of extract (w/v), 2 mL of inoculum, and 6 mL of broth media. Serial dilutions up to 10^8^ were prepared using 9 mL of buffered peptone water and incubated for 48 h at 37°C. Further, the sample was measured at 0, 24, and 48 h for microbial enumeration. Colony counts were performed using a microbial colony counter (Galaxy 230; WIGGENS GmbH, Wuppertal, Germany). The estimated total plate count (ETPC) was calculated following the procedures described in the Bacteriological Analytical Manual (BAM). For total bacterial count, minimal MRS media was used for plating to prevent residual effect of peel‐derived oligosaccharides, thereby allowing accurate enumeration of viable cells.

Quantification of Sugars

3.3

Quantification of total and reducing sugars in melon peel extracts was performed using a modified di‐nitro salicylic acid (DNS) assay (Nielsen 2009). A standard calibration curve was prepared using D‐glucose solutions (0–1 mg/mL). For each assay, 1 mL of sample extract or standard glucose solution was mixed with 1 mL of distilled water, followed by the addition of 3 mL of DNS reagent. The mixtures were incubated for 15 min in a boiling water bath (Wnb‐14; Memmert GmbH, Schwabach, Germany) and subsequently cooled to ambient temperature. After cooling, 5 mL of distilled water was added, and the solution was vigorously shaken. Absorbance was recorded at 540 nm using a UV‐Vis spectrophotometer (VIS‐1100; Biotechnology Medical Services K. Canada Inc., Quebec, Canada). The concentration of reducing sugars in the melon peel extracts was determined from the D‐glucose calibration curve.

Total sugar content, expressed as glucose equivalents, was determined using the phenol–sulfuric acid method. Calibration was performed with D‐glucose standard solutions (0–100 μg/mL). For each analysis, 1 mL of sample or standard glucose solution was mixed with 1 mL of 5% phenol solution, followed by rapid addition of 5 mL of concentrated sulfuric acid (95%–97%). The reaction mixture was allowed to stand for 10 min and then vortexed thoroughly. Absorbance was measured at 490 nm, and total sugar concentration was calculated by reference to the D‐glucose calibration curve. Reducing and total sugar contents were expressed as milligrams of glucose equivalents per milliliter of extract.

HPLC Identification of Phenolics and Sugars

3.3.1

For quantitative analysis of phenolic compounds, 20 μL of each prepared extract was injected into an HPLC system equipped with a UV detector (280 nm) and pump (HP‐1100; Agilent Technologies, Santa Clara, CA, USA) using a C18 cartridge (250 mm × 8 mm). Binary mobile phase system consists of two mobile phases: Mobile phase A [Mili‐Q H_2_O/acetonitrile (95:5)] and Mobile phase B (Mili‐Q H_2_O/acetonitrile 50/50), with flow rate set to 0.8 mL/min and the column operated in gradient mode at room temperature 25°C. Identification and quantification of individual phenolic compounds were based on their specific retention times and calibration curves of respective standards. Results were expressed as milligrams of phenol per 100 g of dry weight.

Sugar profiling of melon peel extracts was carried out using high‐performance liquid chromatography (HPLC Series 200; PerkinElmer Inc., Shelton, CT, USA) following the methodology of (Lee et al. 2025) with slight modification. Melon peel extracts diluted with extraction solvent, 70% (v/v) ethanol at the ratio of 1:10, and filtered through a nylon syringe filter (0.45 μm; Sartorius Stedim, Göttingen, Germany). The filtrate was injected into a Sugar‐Pak column (6.5 × 300 mm). Calcium EDTA (0.004%) served as the mobile phase at a flow rate of 0.5 mL/min. Standard solutions of sucrose, D‐glucose, and D‐fructose (0–1.5 mg/mL) were prepared and filtered under identical conditions. Quantification of sugars in the extracts was performed by comparing the retention times and peak areas of sample chromatograms with those of the corresponding standards.

Non‐Digestible Polysaccharides Analysis

3.4

Quantification of non‐digestible polysaccharides was performed by acid digestion following the method of (Akter et al. 2022). An acidic buffer (pH 1.0) was prepared with the following composition: 0.2 g/L KCl, 14.35 g/L NaHPO₄, 8 g/L NaCl, 8.25 g/L Na₂HPO₄·H₂O, 0.1 g/L CaCl₂·2H₂O, and 0.18 g/L MgCl₂·6H₂O. Freeze‐dried melon peel extracts were reconstituted in distilled water to prepare a 10% (w/v) solution.

To initiate digestion, 5 mL of the extract solution was combined with 5 mL of the acidic buffer and incubated for 4 h at 37°C. The reaction was terminated by the addition of 1 N NaOH. Following acid digestion, enzymatic hydrolysis was performed to evaluate polysaccharide digestibility. α‐Amylase (2 units/mL) was used. A 5 mL aliquot of the acid‐digested sample was mixed with the enzyme solution prepared in phosphate buffer (pH 7; NaH₂PO₄ and NaCl). The mixture was incubated for 6 h at 37°C, and enzymatic activity was terminated by heating at 80°C for 10 min. Non‐digestible polysaccharides were further differentiated into high‐molecular‐weight non‐starch polysaccharides and low‐molecular‐weight oligosaccharides for better assessment of prebiotic functionality. The non‐digestible polysaccharide content of the peel extract was calculated as the difference in total sugar concentration before and after acid and enzymatic digestion using the subtraction method. The concentration of indigestible polysaccharides (Hao et al. 2021) was calculated using Equation (1):

$$[eqn]$$

Non‐starch polysaccharides were calculated as the difference between total non‐digestible polysaccharides obtained after acid–enzyme digestion and oligosaccharides quantified from H_₂_SO_₄_ digestion, expressed as mg/g dry extract according to the following Equation (2):

$$[eqn]$$

Hydrolysis Resistance Assays

3.5

In vitro acid hydrolysis resistance of melon peel extracts was evaluated using simulated gastric conditions. Aqueous hydrochloric acid solutions were prepared at pH 1.0, 2.0, 3.0, and 4.0 by diluting concentrated HCl and adjusting with NaOH. These solutions are not true buffers but were used to mimic gastric acidity for evaluating acid stability. For assay, 5 mL of melon peel extract (1% w/v) was mixed with 5 mL of the corresponding HCl solution. The mixtures were incubated for 6 h at 37°C in a shaking water bath to simulate gastric motility, and hydrolysis was assessed by measuring the increase in reducing sugar content using 3,5‐dinitrosalicylic acid (DNS) method as described previously (Akter et al. 2022).

To evaluate the in vitro enzymatic hydrolysis resistance of α‐amylase (2 units/mL) under varying pH conditions, the enzyme was prepared in 20 mM NaH₂PO₄ buffer adjusted to pH 2.0, 4.0, 6.0, and 8.0. A sodium phosphate buffered system was specifically chosen to maintain the enzyme's structural integrity and activity, which was further maintained at all pH levels during the pre‐incubation and assay analysis. For assay, 5 mL of melon peel extract (1% w/v) and enzyme solution were combined at corresponding pH. The mixture was incubated for 6 h at 37°C. Following incubation, the reaction was terminated by heating for 5 min at 100°C to denature enzyme. The degree of hydrolysis was determined by comparing total and reducing sugar contents before and after specified incubation periods.

Total Phenolic and Antioxidant Assays

4

Sample Preparation

4.1

For the quantification of total phenolics and antioxidant activity, aliquots of the already prepared peel extracts (2.2.1) were used. These aqueous extracts were prepared by diluting in acetone solution for optimal spectrophotometric absorbance of phenolic compounds and for estimation of antioxidant activities (Akhan et al. 2025; Siddiqa et al. 2025). The diluted extract was measured in a 96‐well plate, and absorbance was recorded using Spectrophotometer. All analysis was performed in triplicate, and contents were measured against standard curve.

Total Phenolic Content (TPC)

4.1.1

The total phenolic content (TPC) of melon peel extracts was determined using the Folin–Ciocalteu colorimetric method with slight modifications (Gómez‐García et al. 2020). In this assay, phenolic compounds in the sample reduce the Folin–Ciocalteu reagent (FCR), resulting in the formation of a blue‐colored complex. The intensity of the color, which is proportional to the phenolic concentration, was measured at 765 nm using a UV–V is spectrophotometer. Gallic acid was used as the standard, and results were expressed as milligrams of gallic acid equivalents (mg GAE) per gram of dry extract.

DPPH Radical Scavenging Assay

4.1.2

For the DPPH assay, 3.8 mL of 0.1 mM ethanolic DPPH solution was mixed with the sample extract or Trolox standard. The mixture was incubated in the dark at room temperature for 30 min. Absorbance (A) was measured at 517 nm using a UV–Vis spectrophotometer (UV‐1800; Shimadzu Corporation, Kyoto, Japan). The radical scavenging activity was calculated using Equation (2):

$$[eqn]$$

The results were expressed as milligrams of Trolox equivalents per gram of sample (mg TE/g).

ABTS Radical Scavenging Assay

4.1.3

The ABTS^+^ radical cation was generated by reacting 88 μL of 140 mM potassium persulfate with 5 mL of ABTS stock solution (7 mM). The mixture was incubated at room temperature in the dark for 16 h. The resulting solution was diluted with phosphate‐buffered saline to achieve an absorbance of 0.70 ± 0.02 at 734 nm. For the assay, 100 μL of diluted ABTS solution was mixed with 10 μL of sample extract in a 96‐well microplate. Absorbance was recorded at 734 nm against the calibration standard curve of Trolox. Results were expressed as milligrams of Trolox equivalents per gram of sample (mg TE/g) (Jitpakdee et al. 2021).

Fourier Transform Infrared (FTIR) Spectroscopic Analysis

4.1.4

The molecular structure and functional groups of dried powdered melon peel were characterized using Fourier Transform Infrared (FTIR) spectroscopy (IRAffinity‐1; Shimadzu Corporation, Kyoto, Japan). Spectra were recorded in the mid‐infrared region (400–4000 cm^−1^) at a resolution of 4 cm^−1^, averaging 64 successive scans per sample. Functional groups were identified by comparing the observed absorption bands with reference spectra (Craig et al. 2014; Gong et al. 2025).

Nuclear Magnetic Resonance (NMR) Analysis

4.1.5

The structural and compositional profiling of metabolites in melon peel extracts was further examined using proton nuclear magnetic resonance (^1^H‐NMR) spectroscopy, following the method of (Azizan et al. 2020), with slight modifications. Lyophilized samples were reconstituted in 600 μL of deuterium oxide (D₂O, pH 6) containing 0.1% sodium 3‐trimethylsilyl‐propionate‐2,2,3,3‐d₄ (TSP) as an internal reference. Each sample was mixed with 375 μL methanol‐d₄ (CD₃OD) and 375 μL potassium dihydrogen phosphate (KH₂PO₄) buffer, vortexed for 1 min, ultrasonicated for 10 min, and centrifuged at 10,000 rpm for 5 min. The clear supernatant (600 μL) was transferred to NMR tubes and analyzed using a Bruker Avance‐III 600 MHz spectrometer (Bruker, Germany) at 26°C and 499.88 MHz, with 64 scans and a 3.53 min acquisition time. Data were processed using TopSpin (v4.3.0; Bruker, Billerica, MA, USA) and MestReNova (v14.2.3; Mestrelab Research, Santiago de Compostela, Spain).

Statistical Analysis

4.1.6

All experimental data were analyzed using a completely randomized design (CRD) in Statistix software (v8.1; Analytical Software, Tallahassee, FL, USA). Results are expressed as mean ± standard deviation (SD) from three independent replicates. One‐way analysis of variance (ANOVA) was performed to determine significant differences among treatment means. Post hoc comparisons were carried out using Tukey's Honest Significant Difference (HSD) test, with statistical significance established at p < 0.05.

Results and Discussion

5

Melon Peel Extracts and Prebiotic‐Like Activities

5.1

Peel extracts from honeydew, cantaloupe, and galia melons significantly promoted the growth of Lactobacillus delbrueckii subsp. bulgaricus and Bifidobacterium bifidum compared with the control after 48 h of incubation (p < 0.05; Table 1). All measurements were performed in technical triplicate. For L. bulgaricus , CMPE supported the highest viable population (9.81 ± 0.04 log CFU/g), followed by HMPE (9.76 ± 0.03 log CFU/g) and GMPE (9.71 ± 0.04 log CFU/g), all of which exceeded the T_o_ (9.18 ± 0.01 log CFU/g). For B. bifidum , HMPE promoted the greatest growth (9.97 ± 0.02 log CFU/g), significantly higher than T_o_ (9.60 ± 0.01 log CFU/g), while CMPE (9.79 ± 0.01 log CFU/g) and GMPE (9.76 ± 0.02 log CFU/g) also exhibited enhanced counts. Across all treatments, L. bulgaricus attained consistently higher populations than B. bifidum, likely due to its efficient glycolytic metabolism and tolerance to acidic environments. In contrast, B. bifidum primarily utilizes the fructose‐6‐phosphate phosphoketolase (bifid) shunt pathway and specific oligosaccharides, which may explain its relatively lower utilization of the simpler carbohydrate‐rich melon peel extracts (Kelly et al. 2021).

This study employed a standard in vitro screening approach using minimal medium supplemented with melon peel extracts contributed alongside the medium's existing carbon sources. This approach was employed for initial prebiotic screening as it identifies bioactivity under favorable conditions. Bacterial growth was recorded to assess the prebiotic‐like role of fermentable substrates such as pectin and soluble fibers to support probiotic proliferation (Hao et al. 2021).

It has been reported that L. bulgaricus and B. bifidum ferment dietary carbohydrates via pathways yielding short‐chain fatty acids (SCFAs), which acidify the environment and stimulate bacterial growth (Gómez‐García, Vilas‐Boas, et al. 2022). Although SCFA concentrations were not quantified in the present study, the enhanced probiotic growth observed suggests the presence of fermentable components in extracts. Notably, CMPE, which had the highest indigestible polysaccharide content, provided the most favorable substrate for L. bulgaricus , whereas HMPE best supported B. bifidum , indicating possible differences in oligosaccharide composition that align with strain‐specific metabolic preferences. Compositional analysis confirmed that the melon peel extracts contained substantial levels of non‐digestible polysaccharides and phenolic compounds. These components are strong candidates for mediating the observed bioactivity, as they are known to be resistant to host digestion and fermentable by or stimulatory to gut bacteria. The significant correlation between the presence of these components and prebiotic‐like activity and enhanced growth provides supportive evidence for their functional role. These findings align with a previously reported study that oligosaccharides and the dietary fibers derived from fruit byproducts stimulated prebiotic growth (Thammarutwasik et al. 2009). Overall, melon peel extracts enhanced the growth of both probiotic strains under in vitro conditions, indicating their promising prebiotic function. Further investigations employing in vivo models may also be employed to investigate their mechanism of action and their potential for incorporation into functional foods.

Quantification of Sugars by High‐Performance Liquid Chromatography (HPLC)

5.2

The monosaccharide composition of honeydew, cantaloupe, and galia melon peels is summarized in Table 2, revealing statistically significant differences in sugar content among the varieties (p < 0.05). The polysaccharide extract from cantaloupe peel exhibited the highest concentration of reducing sugars, followed by honeydew and galia peels (Figure 1B). Results observed the significant difference (p < 0.05) in reducing sugar content across the extracts. CMPE contained the highest levels of fructose (221.29 ± 1.01 mg/g) and glucose (221.29 ± 1.01 mg/g), resulting in a total sugar concentration of 438 ± 3.01 mg/g dry extract, compared with HMPE (365 ± 2.51 mg/g) and GMPE (338 ± 1.15 mg/g) peels. Soluble sugar composition varied significantly among different melon cultivars, reflecting genetic and metabolic differences among species. The high levels of free glucose and fructose, though not prebiotic themselves, indicate a rich source of polysaccharides like pectin and hemicellulose in extracts. This indigestible polysaccharide fraction, derived from plant cell walls, is responsible for the extract's prebiotic‐like functionality. This fraction is selectively fermented by beneficial microbes, such as Lactobacillus and Bifidobacterium, to produce short‐chain fatty acids (Zhou et al. 2025).

Quantification of Sugars by HPLC (A) Sugar standards, (B) Melon peel extracts: Honeydew melon peel extract (HMPE), Cantaloupe melon peel extract (CMPE), Galia melon peel extract (GMPE).

Comparable sugar profiles have been reported in the USDA nutritional database, with cantaloupe, honeydew, and galia melon peels containing approximately 9.1, 8.0, and 5.0 g of sugars per 100 g of fruit, respectively, which supports the present findings (USDA 2006). The significant differences in free sugar profiles among cultivars likely reflect the variations in the composition and maturity of this polysaccharide matrix, which in turn results in observed strain‐specific growth responses. Fruit sugar composition, primarily glucose and sucrose, is strongly influenced by ripening stage, as glucose predominates in less mature peels (e.g., GMPE), whereas fructose levels increase with fruit maturity, as observed in HMPE and CMPE (Wu et al. 2025).

Quantification of the Phenolic Compounds by HPLC

5.3

In addition to sugars, phenolic compounds represent another major class of secondary metabolites in fruit peels, contributing significantly to their flavor, aroma, and antioxidant capacity. High‐performance liquid chromatography (HPLC) analysis identified six principal classes of phenolic compounds in melon peels, including phenylethanoids, hydroxybenzoic acids, hydroxycinnamic acids, flavones, lignans, and secoiridoids, etc. As shown in Figure 2, honeydew melon peel contained high concentrations of flavones (30.62 ± 0.55 mg/g) and 4‐hydroxybenzoic acid (30.42 ± 0.43 mg/g), whereas cantaloupe peel exhibited elevated levels of p‐coumaric acid (24.55 ± 0.43 mg/g) and caffeic acid (19.24 ± 0.15 mg/g). Galia melon peel showed comparatively higher concentrations of gallic acid (24.12 ± 0.01 mg/g), p‐coumaric acid (23.65 ± 0.05 mg/g), and pinoresinol (24.50 ± 0.20 mg/g). Overall, the total polyphenol concentration across melon peels was 467 mg/100 g extract, with variety‐specific differences: honeydew (120.65 mg/100 g), cantaloupe (175.87 mg/100 g), and galia (173.38 mg/100 g). These results highlight the biochemical diversity of melon peels and underscore their potential as sources of natural antioxidants for functional food applications. Although phenolic compounds are often associated with antimicrobial activity, the present study focused on their beneficial, selective role in modulating prebiotic growth, as increasing evidence demonstrates that dietary polyphenols can act as microbiota accessible substrates for beneficial bacteria such as Lactobacillus and Bifidobacterium, rather than exerting inhibitory effects at nutritionally relevant concentrations. Moreover, studies have demonstrated that specific phenolic compounds can stimulate prebiotic strains (i.e., Lactobacillus) while selectively inhibiting pathogens, highlighting their role in microbial balance rather than suppression (Petersen and Mansell 2025). Comparable findings have been reported previously, with 4‐hydroxybenzoic acid (326.3 mg/g) and p‐coumaric acid (80.8 mg/g) identified as predominant phenolic constituents in melon peels, consistent with the present results (Rico et al. 2020). Additionally, melon peels have been shown to contain appreciable amounts of apigenin‐7‐glycoside (27.84 ± 1.50 mg/g), oleuropein (18.17 ± 0.05 mg/g), caffeic acid (19.24 ± 0.15 mg/g), and hydroxytyrosol (12.63 ± 0.05 mg/g), which contribute to their free radical‐scavenging capacity (Dimtsas et al. 2024).

HPLC chromatogram of phenolic compounds in melon peel extracts for Honeydew, Cantaloupe, and Galia melon peel at 280 nm. Peak (1) Flavone, (2) 4‐hydroxybenzoic acid, (3) Apigenin‐7‐glycoside, (4) Oleuropein, (5) p‐coumaric acid, (6) Gallic acid, (7) Hydroxytyrosol, (8) Chlorogenic acid, (9) Vanillic acid, (10) Protocatechuic acid, (11) Caffeic acid, (12) Pinoresinol, (13) Naringenin.

Non‐Digestible Polysaccharides

5.4

The non‐digestible polysaccharide content and non‐starch polysaccharides were measured (Table 3). The significant variation (p < 0.05) was observed in the non‐digestible polysaccharide composition of the three melon peel extracts (Table 3). Cantaloupe melon peel extract (CMPE) contained a significantly higher (p < 0.05) concentration of the H_2_SO_4_ non‐digestible fraction, oligosaccharides (29.20 ± 1.00 mg/g), compared to HMPE (16.48 ± 3.24 mg/g) and GMPE (16.77 ± 4.02 mg/g). This specific fraction is a key indicator of prebiotic functionality, due to its high fermentability by beneficial gut microbiota.

Total non‐starch polysaccharides content, which is the comprehensive measure of all non‐digestible polysaccharides. Honeydew peel extracts exhibited the highest total non‐starch polysaccharides content (192.92 ± 3.05 mg/g) as compared to other varieties. This indicates that honeydew peel has a greater abundance of total structural and non‐structural polysaccharides, which may include less fermentable components such as cellulose. These results highlight that cantaloupe peel is enriched in specific types of non‐digestible carbohydrates (i.e., oligosaccharides, soluble fibers) that are conducive to serving as prebiotic‐like substrates, despite not having the highest total non‐starch polysaccharide content. This supports its superior potential as a functional ingredient for gut health, a premise corroborated by recent research showing prebiotic properties of melon peel derivatives (Bilraheem et al. 2024).

Hydrolysis in Simulated Gastric Buffer

5.5

In the present study, the degree of hydrolysis was used to evaluate the susceptibility of melon peel polysaccharides in simulated acid solution. For a compound to exhibit prebiotic potential, it must resist degradation in the upper gastrointestinal tract to reach the colon intact and serve as a substrate for beneficial microorganisms. One‐way ANOVA revealed significant differences (p < 0.05) among melon peel varieties (Figure 3A). All samples demonstrated resistance to hydrolysis, with a general trend of increasing hydrolysis percentage at lower pH levels. The highest hydrolysis was observed for cantaloupe melon peel at pH 2 (9.25%), followed by honeydew (9.11%) and galia (8.24%) at pH 1. Cantaloupe peel exhibited the greatest resistance among the three varieties. At pH 3 and 4, however, variations in hydrolysis were non‐significant (p > 0.05).

Hydrolysis rate in percentage (±SD) of honeydew, cantaloupe, and galia melon peel extracts (A) Simulated gastric buffer (B) α‐amylase. Different letters indicate significant differences (Tukey's HSD, p < 0.05).

Given that gastric juice typically operates within a pH range of 2–4 for approximately 2 h post‐ingestion, it can be inferred that nearly 96% of melon peel polysaccharides would remain intact, enabling them to reach the colon and exert prebiotic effects (Wichienchot et al. 2010). These results are comparable to those reported for galacto‐oligosaccharides (GOS), which are highly resistant to digestion in the small intestine and thus reach the colon intact, where they are selectively fermented by gut microbes (Trijp et al. 2024). Collectively, the results suggest that melon peel polysaccharides possess prebiotic‐like activity due to their resistance to hydrolysis.

α‐Amylase Hydrolysis

5.6

The hydrolysis of melon peel polysaccharides by α‐amylase is illustrated in Figure 3B. Cantaloupe melon peel exhibited the highest degree of hydrolysis (34.67%), followed by honeydew (30.65%) and galia (25.11%). One‐way ANOVA confirmed significant differences among treatments (p < 0.05). Across all samples, hydrolysis decreased progressively with increasing pH.

These findings indicate that cantaloupe melon peel displays the highest resistance to enzymatic degradation, suggesting its ability to support probiotic proliferation in acidic environments (pH 2–6), which simulate the gastric and intestinal conditions. While digestible carbohydrates are typically hydrolyzed into absorbable monosaccharides, non‐digestible oligosaccharides such as oligofructose and inulin are known to withstand enzymatic digestion and reach the colon intact, where they function as prebiotic substrates (Binda et al. 2020). Similarly, melon peel polysaccharides demonstrated notable resistance to α‐amylase hydrolysis, underscoring their potential role as prebiotics within the gastrointestinal tract. Comparing Figure 3A,B reveals that melon peel polysaccharides resist gastric hydrolysis and are partially hydrolyzed by α‐amylase, indicating limited enzymatic hydrolysis during simulated intestinal digestion. This digestive profile is consistent with prebiotic‐like activity, as the polysaccharides can reach the colon largely intact while still providing fermentable substrates. The consistent varietal trend across both assays (cantaloupe > honeydew > galia) further supports the robustness of these findings.

Total Phenolics and Antioxidant Activity

5.7

Significant variation in TPC was observed among the three melon varieties. CMPE contained the highest TPC value (28.12 ± 2.13 mg GAE/g), while GMPE exhibited the lowest (24.33 ± 0.55 mg GAE/g). Earlier reports have also identified diverse bioactive constituents in melon peel, including fatty acids, alkanes, aldehydes, ketones, and flavonoids such as apigenin‐7‐glycoside, all of which contribute to antioxidant and anti‐inflammatory properties (Raji et al. 2017). The antioxidant activity of the melon peel extracts, measured by DPPH and ABTS assays, primarily reflects the radical‐scavenging capacity of phenolic compounds. A strong correlation was observed between radical scavenging and total phenolic content. As shown in Table 4, CMPE exhibited the highest DPPH radical scavenging activity (51.72 ± 5.43 mg TE/g), whereas galia melon peel displayed the lowest (40.32 ± 5.69 mg TE/g). These results align with previous findings demonstrating a positive correlation between total phenolic content (TPC) and antioxidant capacity in melon peels, where higher radical scavenging activity is attributed to enhanced hydrogen atom donation from phenolic compounds (Gómez‐García, Vilas‐Boas, et al. 2022).

The ABTS assay further confirmed these observations. CMPE and HMPE demonstrated the highest ABTS radical scavenging values (37.5 ± 3.07 and 36.5 ± 3.23 mg TE/g, respectively), while GMPE showed the lowest (22.07 ± 1.05 mg TE/g). These antioxidant activities correlate strongly with the elevated polyphenol content (Djouadi et al. 2025), particularly in CMPE and HMPE, which are recognized for their capacity to effectively neutralize free radicals. Overall, melon peel extracts exhibited substantial antioxidant activity that was strongly associated with their phenolic composition. These results underscore the potential of melon peel as a promising by‐product for the development of antioxidant‐rich functional food ingredients, although further characterization of individual antioxidant compounds is warranted.

FTIR Analysis of Melon Peel

5.8

Fourier transform infrared (FTIR) spectroscopy was conducted to identify functional groups in dried, powdered melon peel sample (Figure 4). Spectra were recorded in the range of 4000–400 cm^−1^ following the method of (Tang et al. 2024). The obtained spectra revealed characteristic absorption bands corresponding to carbohydrates and associated bioactive constituents, including hydroxyl, carboxyl, ester, and phenolic functional groups.

FTIR Spectra of Different Varieties of Melon Peels.

A broad absorption band observed between 3400.11–3530.78 cm^−1^ corresponded to O–H stretching vibrations, indicating hydroxyl groups common in alcohols, phenols, and carbohydrates. A prominent peak near 2967.56 cm^−1^ was attributed to C–H stretching, typical of organic compounds. While such stretches can be present in sugars and other organic molecules.

This pattern is consistent with previously reported FTIR spectra of plant materials, where C–H stretching occurs near 2941–2970 cm^−1^ (Mao et al. 2025). A strong band centered at 2610.81 cm^−1^ corresponded to symmetric and asymmetric O–H stretching of carboxylic acids, suggesting the presence of acidic moieties. Bands within 3721.93–3735.05 cm^−1^ reflected free or weakly bonded hydroxyl groups. Strong bands in the region of 1740–1800 cm^−1^ and near 1627 cm^−1^ are characteristic of carbonyl stretching from esters, ketones, and carboxylic acids, which aligns with the phenolic and organic acids determined through HPLC. Critically, the spectra also show absorption in the polysaccharide associated region. Peaks between 1255–1270 cm^−1^ and 1025–1065 cm^−1^, observed across all varieties, possibly represent the C–O and C–O–C stretching vibrations. These results support but do not confirm the presence of prebiotic polysaccharides. While these vibrations were previously observed in carbohydrate structures, their signals are part of a composite profile (Zhou et al. 2025).

Additional absorption around 1800.77 cm^−1^ corresponded to C–H and C=O stretching of esters/carbonyls, whereas the bands at 1627.05 and 1490.42 cm^−1^ represented C=C and –CH_2_–groups, respectively. For honeydew melon peel, prominent bands at 3729.12, 3530.78 cm^−1^ correspond to free hydroxyl groups, while those at 1740.00 and 1710.01 cm^−1^ indicate ester carbonyl (C=O), showing the presence of polyphenols (Tang et al. 2023). For cantaloupe melon peel, spectral bands at 1789.07 and 1755.41 cm^−1^ show esters or carboxylic acid groups, and the band near 534.65 cm^−1^ is associated with C=C stretching in polyphenols (Zahed et al. 2023). Furthermore, the distinct absorptions observed at 1066 and 1271 cm^−1^ fall within the region characteristic of C–O and C–O–C stretching vibrations found in carbohydrate containing compounds (Zhang et al. 2014). The presence of these bands supports other analytical data (i.e., sugar content) and is consistent with cantaloupe peel containing a notable fraction of carbohydrate structure. For galia melon peel, strong bands were detected at 2610.81 and 1800.77 cm^−1^, corresponding to C=O stretching of acids and aldehydes, respectively (Shofia et al. 2018).

Critically, the spectra also show absorption in the polysaccharide associated region. Peaks between 1255–1270 and 1025–1065 cm^−1^, observed in three varieties, can be assigned to C–O and C–O–C stretching vibrations. While these vibrations are present in carbohydrate structures within the heterogeneous peel powder and are not the dominant feature.

Collectively, FTIR profiles show that honeydew, cantaloupe, and galia melon peels possess a complex biochemical structure rich in hydroxyl, carbonyl, and aromatic functional groups. These groups are associated with carbohydrates (both structural and potentially soluble), phenolic compounds, and other biomolecules, which provide the foundation from which bioactive, water‐soluble components, including the oligosaccharides and phenolic compounds implicated in the observed prebiotic‐like activity, can be extracted.

Nuclear Magnetic Resonance (NMR) Analysis

5.9

Quantitative ^1^H‐NMR analysis, in conjunction with HPLC and FTIR, enabled a comprehensive identification of metabolites in the peels of honeydew, cantaloupe, and Galia melons. The ^1^H‐NMR spectra (Figure 5) displayed strong resonances in the mid‐field region (δ 3.0–5.0), corresponding primarily to sugars such as sucrose, glucose, β‐glucose, and fructose. In honeydew peel, dominant resonances were detected in this region, along with minor peaks representing organic acids including malic acid (δ 2.82), citric acid (δ 2.72), and succinic acid (δ 2.41). These acids contribute to antioxidant defense through reactive oxygen species (ROS) reduction and NADH regeneration in the tricarboxylic acid (TCA) cycle. Resonances at δ 5.20 were attributed to aliphatic protons of pectin, specifically α‐GalA H‐1, showing the presence of peel polysaccharides. Polyphenolic compounds, including chlorogenic acid (δ 6.10) and caffeic acid (δ 6.30), were also identified, aligning with earlier NMR‐based profiling of sweet melon varieties (Girelli et al. 2018).

1H‐NMR spectrum of melon peel. (A) Honeydew melon peel: 1: Sucrose, 2: Fructose, 3: Glucose, 4: Pectin, 5: Malic acid, 6: Succinic acid, 7: β‐glucose, 8: Citric acid, 9: Chlorogenic acid, 10: Caffeic acid. (B) Cantaloupe melon peel: 1: Sucrose, 2: Fructose, 3: Glucose, 4: α‐xylose, 5: Chlorogenic acid, 6: Alcohol, 7: Glutamate, 8: Acetic acid, 9: Citric acid, 10: Quercetin. (C) Galia melon peel: 1: Sucrose, 2: Fructose, 3: Glucose, 4: Galacturonic acid, 5: Xylans, 6: Glutamine, 7: Chlorogenic acid, 8: Malic acid, 9: Esters.

In cantaloupe peel, strong resonances between δ 3.2–5.0 confirmed the presence of sucrose (δ 3.55), glucose (δ 4.64), and fructose (δ 4.11). Distinct peaks at δ 5.22 and δ 5.51 corresponded to α‐xylose, while a resonance at δ 8.55 indicated hydroxyl (–OH) groups. Polyphenols such as chlorogenic acid (δ 7.51) and quercetin (δ 6.52) were also identified, along with organic acids including glutamate (δ 2.61), acetic acid (δ 1.99), and citric acid (δ 2.72). These findings agree with previous reports on Cucurbitaceae species, in which sugars dominate the mid‐field region and organic acids appear in the high‐field range (Sulaiman et al. 2020).

The Galia melon peel spectrum exhibited moderate‐intensity signals for sucrose (δ 3.81), fructose (δ 3.62), and glucose (δ 4.50) compared with honeydew and cantaloupe peels. Galacturonic acid, the structural component of pectic polysaccharides, was identified at δ 5.21, δ 3.71, and δ 5.60, with a resonance at δ 3.90 indicating partial methyl esterification. Additional signals were assigned to xylan (δ 3.20), glutamine (δ 2.31), and malic acid (δ 2.52), while a strong peak at δ 7.10 confirmed chlorogenic acid. These observations are consistent with previous reports identifying galacturonic acid through characteristic chemical shifts (α‐GalA: H‐1 δ 5.10, H‐2 δ 3.72, H‐3 δ 3.97), confirming its role in pectic structure (del Amo‐Mateos et al. 2024).

Overall, the spectra revealed abundant sugars, organic acids, polyphenols, and structural polysaccharides across all melon peels. Plant‐derived polysaccharides are increasingly recognized for their immunomodulatory potential (Chen et al. 2025; Bagheri et al. 2024). For instance, polysaccharides extracted from Brassica oleracea L. have demonstrated diverse biological properties, including anti‐cancer, anti‐fatigue, hypoglycemic, antioxidant, and immunostimulatory effects (Wang et al. 2025).

Conclusion

6

The present study demonstrated that melon peel polysaccharides exhibit prebiotic‐like potential by selectively stimulating the growth and proliferation of probiotic strains such as Bifidobacterium bifidum and Lactobacillus delbrueckii subsp. bulgaricus. Comprehensive analyses using HPLC, FTIR, and ^1^H‐NMR confirmed the presence of polysaccharides, phenolic antioxidants, and bioactive compounds in melon peel, a major byproduct of the fruit processing industry. The FTIR and NMR spectra further revealed structural features consistent with prebiotic‐like oligosaccharides and phenolic constituents. Collectively, these findings highlight melon peel as a sustainable and value‐added source of functional ingredients for gut‐health‐promoting foods. Further in vivo validation is required to elucidate its mechanisms of action and to explore its potential applications in food, pharmaceutical, and biopackaging sectors, contributing to food waste valorization and circular economy initiatives.

Author Contributions

Conceptualization and experimentation, N.S. and S.A.; methodology, A.L., M.A.F., and D.A.; software, T.A. and N.S.; validation, S.A. and A.L.; formal analysis, S.A. and M.B.; data curation, T.A. and M.B.; writing – original draft preparation, N.S.; writing – review and editing, N.S. M.B., T.A., D.A., and M.A.F.; supervision, S.A. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by King Saud University, ORF‐2026‐641.

Conflicts of Interest

The authors declare no conflicts of interest.