Antioxidant capacity, quality attributes, and chemical characterization of commercial orange-fleshed honeydew melons

Capacidade antioxidante, atributos de qualidade e caracterização química de melões comerciais de polpa alaranjada

ABSTRACT:

Orange-fleshed non-netted honeydew melon has high nutritional and economic potential, being widely appreciated as a refreshing sweet fruit. Therefore, evaluating commercial samples of such relevant products for the fresh fruit market is of great importance. This study investigated the antioxidant capacity, quality parameters, and chemical composition of honeydew melons from the Brazilian market. The values of pH and °Brix determined for melon samples were 6.5 ± 0.30 and 9.2 ± 0.80 g/100 g (fresh weight), respectively, which agree with the results expected for high-quality melons. The chromatography analysis revealed sucrose (49% of total sugar) as the main sugar, followed by fructose (30%) and glucose (21%). Carotenoids, which are directly linked to the characteristic orange color, showed a total level of 270.59 µg/g (dry weight). Additionally, the higher b^* value compared to a^* value indicates the highest yellow contribution. Regarding the antioxidant assays, in addition to presenting antioxidant capacity for both methods applied, DPPH and FRAP, levels ranging from 16.40 ± 0.21 µmol ascorbic acid equivalent/g to 56.98 ± 0.80 µmol Trolox equivalent/g (dry weight) were reported in melon extracts. Moreover, the results were higher in terms of FRAP than DPPH. Therefore, the results underscore the evaluated honeydew melons as valuable sources of bioactive compounds, such as carotenoids and phenolics, which contribute to their antioxidant properties. Besides, analyses of color, pH, and total soluble solids content also reflect the quality attributes.

Key words: honeydew melon; gas chromatography; carotenoids; antioxidant assays

RESUMO:

O melão de polpa alaranjada honeydew apresenta elevado potencial nutricional e econômico, sendo amplamente apreciado como fruta doce e refrescante. Portanto, avaliar amostras comerciais de produtos tão relevantes para o mercado de frutas frescas é de grande importância. O objetivo deste estudo foi investigar a capacidade antioxidante, os parâmetros de qualidade e a composição química de melões do mercado brasileiro. Os valores de pH e ºBrix determinados para as amostras de melão foram 6,5 ± 0,30 e 9,2 ± 0,80 g/100 g (peso fresco), respectivamente, o que está de acordo com os resultados esperados para melões de alta qualidade. A análise cromatográfica revelou a sacarose (49% do açúcar total) como principal açúcar, seguida pela frutose (30%) e glicose (21%). Os carotenóides, que estão diretamente ligados à cor laranja característica, apresentaram teor total de 270,59 µg/g (peso seco). Além disso, o maior valor de b^* comparado ao valor de a^* indica a maior contribuição da cor amarela. Quanto ao potencial antioxidante, além de apresentar capacidade antioxidante para ambos os métodos aplicados, DPPH e FRAP, níveis variando de 16,40 ± 0,21 µmol equivalente de ácido ascórbico/g a 56,98 ± 0,80 µmol equivalente de Trolox/g (peso seco) foram encontrados nos extratos de melão. Ademais, os resultados foram maiores em termos de FRAP do que em DPPH. Desta forma, os resultados destacam os melões avaliados como fontes valiosas de compostos bioativos, como carotenóides e fenólicos, que contribuem para suas propriedades antioxidantes. Além disso, análises de cor, pH e teor de sólidos solúveis totais também refletem os atributos de qualidade.

Palavras-chave: melão; cromatografia gasosa; carotenoides; ensaios antoxidantes

INTRODUCTION

Fruits and vegetables are underscored as important sources of energy, nutrients, and bioactive compounds, being crucial elements of the human diet. They have potential health-promoting effects, playing a role in preventing numerous chronic diseases, oxidative stress, and inflammation processes. Thus, they have been a mainstay of healthy dietary recommendations (WALLACE et al., 2020).

Orange-fleshed non-netted honeydew melon (Cucumis melo L.), Cucurbitaceae family, is obtained by backcrossing green-fleshed honeydew with orange-fleshed cantaloupe or other β-carotene-rich melons (LESTER & SAFTNER, 2008). It is a remarkable fruit in the fresh fruit market that is valued all over the world due to its combination of sweet taste, pleasing flavor, and nutritional value (LESTER & SAFTNER, 2008; IMEN et al., 2023). Additionally, non-netted honeydew melon appears to be a safer choice due to its lack of a netted rind, which is well known to harbor bacteria, including human pathogens such as Salmonella and Escherichia coli (LESTER & HODGES, 2008; LESTER & SAFTNER, 2008).

This species contains relevant bioactive components, such as vitamins, phenolic compounds, and carotenoids (THAKUR et al., 2019; BILEVA et al., 2020). The latter is responsible for the distinctive orange color of the ripe fruit, which is primarily linked to β-carotene content (PULELA et al., 2022). Furthermore, these compounds possess high antioxidant potential, indicating that melon consumption may reinforce the human endogenous antioxidant system. Therefore, a protective effect against the damage caused by oxidative stress may be expected (AKBARI et al., 2022; NARDINI, 2022).

Quality traits are key determinants of customer’s purchase decisions and are also preconized by legislation. Therefore, efforts have been made by fruit producers to ensure a high-quality final product, which in terms of melon include parameters like pH, color, total soluble solid content, and sweetness (KYRIACOU et al., 2018; THAKUR et al., 2019). Although the nutritive value of melons is extensively reported, it is well known that the bioactive composition of natural materials is influenced by diverse factors, such as genetics, soil nutrients, light exposure, and climate conditions, among others (LESTER et al., 2007; KYRIACOU et al., 2018; THAKUR et al., 2019; PULELA et al., 2022). Thus, it is worth investigating each specific type of sample to provide comprehensive information.

In this context, this study characterized commercial orange-fleshed non-netted honeydew melons marketed in Brazil by their proximate composition, pH, color, and sugar amount, as well as determine their contents of carotenoids and phenolic compounds. Besides, the antioxidant potential of samples was also assessed in vitro by the DPPH and FRAP assays.

MATERIALS AND METHODS

Orange-fleshed honeydew melons

Orange-fleshed non-netted honeydew melons (Cucumis melo L. cv Honeydew) were cultivated in a commercial farm located in Mossoró, Rio Grande do Norte, Brazil (05º11’S 37º20’O). The fresh samples, a total of eighteen melons, were obtained from a national retailer (Grupo Benassi, CEASA, Rio de Janeiro, Brazil). They were selected from six different boxes at the retailer and classified by size (14 to 16 cm diameter), weight (1800 to 2000 g), maturity level (9 to 11 ºBrix), and physical damage. Subsequently, the samples were washed, sanitized using a 200 ppm solution of sodium hypochlorite for 10 minutes, and stored under refrigeration (4-6 ºC) until analyses, which were carried out within a week. For analyses, different cuts were obtained from the melon mesocarp.

Physico-chemical characterization

The contents of moisture and ash, pH, and soluble solids (ºBrix) were determined according to the methodology described by the Association of Official Analytical Chemists (AOAC, 1997). The moisture was determined by drying the samples in an oven at 105 ºC until constant weight. Ash content was determined by incinerating the samples in a muffle at 550 ºC for 6 h. The soluble solids content was measured at 25 ºC in a benchtop Abbe refractometer (Quimis - model Q767B, São Paulo, Brazil) and the pH in a benchtop pH meter (Analyser - model pH300, São Paulo, Brazil) at 25 ºC. The results were expressed in grams per 100 grams of fresh weight (g/100 g FW).

Total carotenoids content

The total carotenoid content was assessed according to FLESHMAN et al. (2011), considering the absorption coefficient (A _1cm(1%) ) of 2592 obtained by using a spectrophotometer (Beckman Coulter, model DU 640, CA, USA) and quartz cuvettes with a 1-cm light path regarding β-carotene at a given wavelength at 449 nm. The results were expressed in µg β-carotene/g of dry weight (DW).

Sugar content

The extraction was carried out with 1 g of ground melon mesocarp and an ethanol/water solution (5 mL, 80:20, v/v). The sugar composition (fructose, glucose, and sucrose) was determined by gas chromatography and the procedures described by DE LA FUENTE et al. (2011) were used to prepare the trimethylsilyl derivatives (TMS). The TMS solution (1 µL) was injected into a Shimadzu 2010 GC (Tokyo, Japan), equipped with an AOC-20i auto-sampler, a split-splitless injector, a flame ionization detector, and fused-silica capillary column (30 m x 0.25 mm i.d.; 0.25 µm film thickness) coated with 65% diphenyl-polysiloxane-35% dimethyl-polysiloxane (Rtx 65MS, Restek, Bellefonte, PA, USA). The injector (split 1:20) and detector temperatures were both set at 280 ºC. The oven temperature was programmed to 160 ºC for 3 min, raised to 200 ºC at 2 ºC/min and from 200 to 280 ºC at 5 ºC/min and held for 5 min. Hidrogen was used as carrier gas at a flow rate of 4 mL/min. The identification and quantification of the peaks were carried out by comparing the peak retention times with those of the commercial standards and by internal standardization, respectively. The response factors of each sugar (0.1 to 1.0 mg) were evaluated with respect to the methyl-α-D-glucopyranoside.

Total phenolic compounds content and antioxidant capacity

Extract preparation

The extract preparation was performed as described by RUFINO et al. (2010), with minor modifications. The sample (7 g) was stirred in water:acetone:methanol solution (35 mL, 40:30:30, v/v/v) at 25 ºC for 1 hour. The mixture was filtered under vacuum through a paper filter (19 µm). Subsequently, the residue was washed twice with 5 mL of the extraction solution and filtered. The supernatants combined in a 50 mL volumetric flask and the volume was completed with the extraction solution.

Content of total phenolic compounds

The total phenolic content was assessed using the Folin-Ciocalteu reagent as described by SWAIN & HILLIS (1959), with minor modifications. The Folin-Ciocalteu reagent (1 mL) was mixed with 1 mL of extract and 10 mL of distilled water. After 3 min, 1.5 mL of 10% sodium carbonate solution was added to the mixture, which was homogenized and incubated for 2 hours at room temperature in the dark. The absorbance was determined at 725 nm using a spectrophotometer (Beckman Coulter, model DU 640, CA, USA). The results were determined using standard curves and expressed as: trolox (Abs = 0.00126 x + 0.124, R² = 0.978, x: 50 - 1000 µM of TE, n = 7), ascorbic acid (Abs = 0.00486 x + 0.0389, R² = 0.998, x: 10 - 600 µM of AAE, n = 12) and gallic acid (Abs = 0.00454 x + 0.0107, R² = 0.998, x: 30 - 200 µM of GAE, n = 7), i.e. TE, AAE, and GAE, respectively, in µmol of each compound per kg of dry weight. “n” is the number of different concentrations (x, in µM of each antioxidant compound) evaluated in the evaluated range.

DPPH free radical scavenging assay

The DPPH assay was performed according to RUFINO et al. (2010). The DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging was determined by adding the extract (100 μL) to a 0.06 mM methanolic DPPH solution (3.9 mL). The mixture was homogenized and left resting for 1 hour in the dark at room temperature. The absorbance was measured at 517 nm using a spectrophotometer (Beckman Coulter, model DU 640, CA, USA). The results were expressed in terms of TE (Abs = -0.00101 x + 0.668, R² = 0.999, x: 10 - 600 µM of TE, n = 9), AAE (Abs = -0.00106 x + 0.680, R² = 0.999, x: 10 - 600 µM of AAE, n = 12), and GAE (Abs = -0.00343 x + 0.672, R² = 0.998, x: 30 - 200 µM of GAE, n = 6).

Ferric reducing antioxidant power (FRAP) assay

For the FRAP assay, 2.7 mL of freshly prepared FRAP reagent (TPTZ, FeCl_3, and acetate buffer) was mixed with the extract (90 μL) and distilled water (270 μL). The mixture was heated at 37 ºC for 30 minutes (THAIPONG et al., 2006). The absorbance was determined at 595 nm with a spectrophotometer (Beckman Coulter, model DU 640, CA, USA) and the results were expressed in terms of TE (Abs = -0.000962 x + 0.00857, R² = 0.999, x: 50 - 400 µM of TE, n = 5), AAE (Abs = 0.00170 x -0.00630, R² = 0.998, x: 10 - 200 µM of AAE, n = 8), and GAE (Abs = 0.00206 x - 0.0112, R² = 0.994, x: 30 - 200 µM of GAE, n = 7).

Instrumental color analysis

Three samples were taken and ten measurements were made on the pulp from the equatorial area of each fruit, using a Color Quest II bench spectrophotometer (Hunter Lab, Reston, USA) with six readings for each sample at 10º angle and the D65 light source. The CIELab coordinates (a^*, b^*, L^*) were read directly on the equipment, and the chroma (C ^* ) and hue angle (h _ab) were calculated according to BARRET et al. (2010).

Statistical analysis

All analyses were performed in triplicate. All data are presented as mean values ± standard deviations. For sugar analysis using GC-FID, each calibration curve was evaluated using the average relative error (P), according to Equation 1.

$P\left(\%\right)=\frac{100}{N}\sum _{i=1}^N\left|\frac{Y-Ȳ}{Y}\right|$(1)

where Y and Ȳ are experimental and predicted values, respectively. N represents the number of experimental points.

RESULTS AND DISCUSSION

The results obtained for moisture and ash content, pH, and total soluble solids of orange-fleshed honeydew melons are presented in table 1. The moisture content was 92.06 ± 0.63 g/100 g FW, which was higher than the values determined by MALLEK-AYADI et al. (2022) (83.05 g/100 g) for ripe melons belonging to “Maazoun” cultivar obtained from Skhira (Sfax, Tunisia). In general, lemons contain high water content, which makes them suitable fruits for preventing dehydration and having a refreshing sensation. However, the moisture level of fruits may be influenced by numerous factors, including cultivar and ripening stage. It was demonstrated by VILLANUEVA et al. (2004), who reported values ranging from 83.60 to 94 g/100 g for melons from the Piel de Sapo cultivar evaluated at different ripening stages. Moreover, this study showed that moisture gradually decreased with ripening. The ash level assessed for the commercial melons was 0.56 ± 0.09 g/100 g FW, which was in agreement with the results reported by VILLANUEVA et al. (2004): from 0.41 g/100 g (early immature) to 0.68 g/100 g (ripe).

Table 1
Physico-chemical characterization of commercial orange-fleshed honeydew melons.

Parameter	----------------------------------------Value----------------------------------------
Moisture (g/100 g, FW)	92.06 ± 0.63
Ash (g/100 g, FW)	0.56 ± 0.09
pH	6.5 ± 0.30
Soluble solids (g/100 g, FW)	9.2 ± 0.80
Total carotenoid (µg β-carotene/g, DW)	207.59 ± 5.05

• Results presented as mean ± standard deviation, n = 3.
• DW = dry weight; FW = fresh weight.

The pH value determined in melon samples was 6.5 ± 0.30, which corresponds to the values reported for some melon varieties in which pH values ranged from 5.44 to 6.55 (VILLANUEVA et al., 2004; MILLER et al., 2018; MALLEK-AYADI et al., 2022). The soluble solids content was 9.2 ± 0.80 g/100 g FW. The total soluble solid content is an important quality attribute that indicates sugar level, being directly linked to fruit sweetness and acceptability. Thus, values above 8 °Brix have been described as the minimum recommended value for melon fruits (VILLANUEVA et al., 2004), regarding the characteristic desired for marked. However, it is known that consumers’ preferences may vary depending on several parameters, especially the ones related to cultural habits.

The total carotenoid content of melon samples was 270.59 µg/g DW (1640 µg/100 g FW), higher than the values reported by FUNDO et al. (2018) (68.92 µg/g) and MALLEK-AYADI et al. (2022) (41.72 µg/g) when evaluating ripe Cucumis melo L. var. reticulatus and Cucumis melo L. belonging to “Maazoun” cultivar, respectively. In addition, MARTUSCELLI et al. (2016) investigated the effect of phosphorus fertigation on melon fruits and determined levels ranging from 101.2 to 162.9 µg/g DW. Indeed, as the biosynthesis of molecules, like carotenoids, is strongly related to agri-environmental factors, variable results can be found in the literature.

Carotenoids are isoprenoids synthesized by all photosynthetic organisms. In plants, carotenoids are important pigments, contributing to yellow, orange, and red coloration. In terms of human health, the consumption of carotenoids has been linked to numerous bioactivities, primarily attributed to their antioxidant potential (YOUNG & LOWE, 2018; SUN et al., 2022). Carotenoids consist of a series of conjugated C - C bonds that allows their action as singlet molecular oxygen quenchers and free radical scavengers (YOUNG & LOWE, 2018). They are divided into two major groups. Therefore, the literature has reported the presence of hydrocarbon carotenoids, such as β-carotene, and oxygenated derivatives, like lutein (LECHOLOCHOLO et al., 2022; PULELA, et al., 2022) in melons. Besides, carotenoids are critically relevant for humans as precursors of vitamin A, which is one of the most important micronutrients affecting human health (SLOTKOWSKI et al., 2023).

Regarding the instrumental color analysis, the honeydew melon samples presented L^*, a^*, and b^* values of 61.79, 17.20, and 35.95, respectively. The L^* value, which indicates the lightless of samples, is in agreement with the one determined for Italian melons (61.60) by MARTUSCELLI et al. (2016). However, melons studied by MALLEK-AYADI et al. (2022) showed 64.76, being more light-colored. The higher b^* value indicates the great yellow contribution. A similar trend was observed by other authors (MALLEK-AYADI et al. 2022; JIANG et al., 2023). However, variable values can be found for parameters a^* and b^*. MALLEK-AYADI et al. (2022), for example, determined − 3.58 and 7.94 for a^* and b^* values, respectively.

The orange color of honeydew melon was also noticeably related to C^* (39.85) and h _ab values (64.46). LESTER & SATFNER (2008) reported values of C^* from 37.2 to 38.4 and of h _ab from 70 to 71 for hybrid melons from different years of cultivation. C^* values lower than the one found in the present study were assessed by ERCAN et al. (2023) (from 11 to 14.9) and by FALAH et al. (2015) (33.2), who reported higher values for hue angle. The color attribute is an important quality parameter of foods, and, in orange-fleshed melons, this property is mainly related to the carotenoid content. It is consistent with previous studies that reported that the intensity of the orange color in the pulp of different melons is primarily due to their β-carotene content (FLESHMAN et al., 2011; PULELA et al., 2022).

Another characteristic of honeydew melon is its sweetness. The sugar content, consisting of glucose, fructose, and sucrose, determined in orange-fleshed melons was 765.3 mg/g, dry basis. It was lower than that found by LESTER (2008) in the same variety (847 mg/g, dry basis), but higher than the one reported in a study by LESTER et al. (2005) for cantaloupe melons (499-594 mg/g, dry basis).

Sucrose was the main sugar, representing 49% of total sugar, followed by fructose (30%) and glucose (21%), respectively. A similar sugar profile was reported by other authors, who also describe sucrose as the predominant sugar in orange-fleshed melons (WU et al., 2020; ERCAN et al., 2023). ERCAN et al. (2023) showed that the irrigation regime had a significant effect on sucrose and total sugar content. However; although different contents were detected in samples, sucrose remained as the main contributor to total sugar content. The influence of organic fertilization was demonstrated by BILEVA et al. (2020), who observed a similar trend regarding the sugar profile.

Additionally, figure 1 shows a chromatogram obtained for sugar TMS-derivates from orange-fleshed honeydew melon. All the chromatographic graphs obtained have shown high separation efficiency, sensitivity, and resolution. Despite the main fructose TMS-derivatives (peaks 3 and 4) have presented an overlap between them, the quantitative purpose was achieved for each sugar evaluated. Thus, it is important to highlight the high separation efficiency for fructose, glucose, and sucrose in studied samples by GC-FID technique used.

Figure 1
GC-FID chromatogram obtained for sugar extract from commercial orange-fleshed honeydew melons. Peak identification: hexane (peak 1); fructose (peaks 2-5); methyl α-D-glucopyranoside (peak 6); glucose (peaks 7-8) and sucrose (peak 9).

Honeydew melon is primarily valued due to its rich composition in bioactive antioxidant compounds. Thus, the total phenolic content and the results obtained by DPPH and FRAP assays are presented in table 2. The results were expressed in terms of ascorbic acid (AAE), Trolox^® (TE), and gallic acid (GAE) equivalents.

Table 2
Antioxidant capacities (DPPH and FRAP assays) and total phenolics content (TPC) of commercial orange-fleshed honeydew melons.

	DPPH	FRAP	TPC
Ascorbic acid equivalent (µmol AAE/ g, DW)	3.03 ± 0.13	12.11 ± 0.70	16.40 ± 0.21
Trolox® equivalent (µmol TE/g, DW)	2.11 ± 0.14	20.00 ± 1.24	56.98 ± 0.80
Gallic acid equivalent (µmol GAE/ g, DW)	0.72 ± 0.04	10.22 ± 0.58	18.11 ± 0.22

• DPPH = 2,2-diphenyl-1-picrylhydrazyl; FRAP = Ferric reducing antioxidant power. TPC = Total phenolics content. Results presented as mean ± standard deviation, n = 3. DW = dry weight.

For phenolic compounds, contents of 16.40 ± 0.21 µmol AAE/g (DW), 56.98 ± 0.80 µmol TE/g (DW), and 18.11 ± 0.22 µmol GAE/g (DW) were determined in orange-fleshed honeydew melon samples, revealing higher levels when Trolox was used as standard. Analyses performed to determine the total content of phenolic compounds are commonly carried out in studies aiming to characterize the antioxidant potential of natural materials, such as orange-fleshed melons. However, results are expressed using different units and standards, making it difficult to compare data from the literature to the values found herein.

Samples presented lower antioxidant capacity by the DPPH method compared to FRAP. Therefore, lower values for all equivalent standards utilized were determined: 3.03 ± 0.13 µmol AAE/g, 2.11 ± 0.14 µmol TE/g, and 0.72 ± 0.04 µmol GAE/g (DW), with the highest antioxidant capacity when ascorbic acid was used as standard. Conversely, the FRAP assay presented a similar pattern to the total phenolics content, where using Trolox as standard provided the greatest result: 20.00 ± 1.24 µmol TE/g (DW), while values of 12.11 ± 0.70 µmol AAE/g (DW) and 10.22 ± 0.58 µmol GAE/g (DW) were assessed for ascorbic acid and gallic acid, respectively. Thus, regardless of the antioxidant assay considered, the lowest results were achieved when gallic acid was used.

Vegetables present a diversity of bioactive compounds with varied chemical structures and antioxidant characteristics. Furthermore, antioxidant assays rely on different mechanisms. Therefore, complex samples have diverse activity patterns in each method, providing different results for the different assays (GULCIN, 2020). In this way, using methods based on distinct principles is a suitable strategy to achieve more accurate and comprehensive results.

The DPPH method is based on the scavenging of this radical (DPPH^*) through the addition of a radical species or an antioxidant that decolourizes the DPPH solution. In turn, the FRAP assay measures the ability of antioxidants to reduce a ferric tripyridyltriazine complex. Thus, FRAP assesses the reduction of the Fe(III) complex to Fe(II), which occurs due to the presence of reducing agents (GULCIN, 2020). Additionally, phenolic compounds are the main class of antioxidant compounds present in natural materials (NARDINI, 2022). Although, other classes, such as carotenoids, tocopherols, and ascorbic acid, also have antioxidant properties, high contents of phenolic compounds have shown a strong positive correlation with the great antioxidant capacity of natural extracts (BILEVA et al., 2020; BUTKEVIČIŪTĖ et al., 2022).

The antioxidants reported in natural extracts are represented by a heterogeneous category of molecules that may present synergistic, antagonistic, and/or additive antioxidant effects. Indeed, each vegetable species will present a different antioxidant capacity, contributed by different antioxidant components (OLSZOWY-TOMCZYK, 2020). Furthermore, there is a wide degree of variation concerning the contents of bioactive compounds since they are highly affected by factors such as maturity stage, climate, cultivation conditions, and genetics, among others (MARTUSCELLI et al., 2016; BILEVA et al., 2020; PULELA et al., 2022).

In the present study, the orange-fleshed melon extract showed antioxidant capacity for both methods applied (DPPH and FRAP), as well as the presence of phenolic compounds. These findings are in agreement with the literature that describes the antioxidant potential of this fruit (BILEVA et al., 2020; PULELA et al., 2022; RODRÍGUEZ-RICO et al., 2022).

CONCLUSION

The overall results highlight the quality attributes of the studied samples in terms of pH and soluble solid contents. The GC-FID technique was adequate to quantify the main sugars in orange-fleshed honeydew melons, showing sucrose as the major one. Additionally, the antioxidant potential presented by the fruit extract for both methods applied may be supported by the levels of carotenoids and phenolic compounds assessed in this study. As DPPH and FRAP assays are based on different mechanisms great results were determined, revealing the free-radical scavenging and metal ion chelator potential of melon extracts, although higher values have been reported for the FRAP assay. Therefore, given the economic and nutritional relevance of honeydew melons and the valuable results presented herein, further studies regarding evaluating commercial samples of fruits must be encouraged.

ACKNOWLEDGEMENTS

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The authors are also grateful to Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Programa de Extensão Universitária/Ministério da Educação/Secretaria de Educação Superior (PROEXT/MEC/Sesu).

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• 0
  CR-2024-0253

Edited by

• Editors: Alessandro Dal’Col Lúcio (0000-0003-0761-4200) Ivo Oliveira (0000-0002-0866-953X)

Publication Dates

• Publication in this collection
  25 Oct 2024
• Date of issue
  2025

History

• Received
  03 May 2024
• Accepted
  19 June 2024
• Reviewed
  16 Aug 2024