Watermelon Rind Research Articles

The Utilization of Calcium in Watermelon Rind Extract for Osteoporosis Drug Agent

Calcium is one of the essential minerals for the body, especially in the elderly and pregnant women. Using natural materials containing calcium is very important, especially natural materials that are only used as waste, such as watermelon rind. Watermelon rind has a calcium of 31 mg. Therefore, it is very efficient to be used. The manufacture of this osteoporosis drug does not refer to calcium from watermelon rind extract alone. However, it is supported by other herbal ingredients such as rhizomes (ginger, curcuma, turmeric, and fingerroot). The method of extracting calcium from watermelon rind used the destruction method. After being extracted, the extraction and some mixed with the rhizomes were tested, such as calcium levels, XRF, XRD, and FTIR tests. The result of the study showed that all samples were confirmed to have calcium. High calcium content of 13.30 percent was found in the watermelon rind extract sample from watermelon fruit measuring 6 kg mixed with rhizomes. All samples' calcium level test results had a dominant value of 495 ppm.DOI: 10.17977/um024v8i12023p001

Bioavailability of Citrulline in Watermelon Flesh, Rind, and Skin Using a Human Intestinal Epithelial Caco-2 Cell Model

Watermelon produces many byproducts (watermelon rind and skin) even though those components contain various bioactive compounds, including citrulline. This study evaluated the citrulline concentration, total phenolic content, and antioxidant activity (DPPH and FRAP assays) of different parts of watermelon and investigated the bioavailability of citrulline from different parts of watermelon using an in vitro human intestinal epithelial Caco-2 cell monolayer model. Solid-phase extracted watermelon flesh, rind, and skin samples were treated on a Caco-2 cell monolayer for 1, 2, and 4 h. The collected basolateral solution at each time point was analyzed for the percentage of citrulline transport. Watermelon flesh had the highest citrulline content, but the watermelon skin had the highest total phenolic content and antioxidant activity compared to other watermelon parts. The citrulline bioavailability showed greater % transport in watermelon skin than in watermelon flesh, rind, and L-citrulline standard. It may be due to the different food matrices of watermelon parts. This suggests that the utilization of watermelon by-products such as skin would help develop value-added products with better bioavailability of citrulline. However, since this study was conducted with an in vitro cell model, more extensive research with in vivo studies will be needed.

Valorization of Waste Watermelon Rinds as aBio-adsorbent for Efficient Removal of Methylene Blue Dye from Aqueous Solutions.

Nature-based solutions (NBSs) for remediation of various emerging contaminants have gained impetus during the last few decades. In the current study, watermelon (citrullus lanatus), a highly consumed seasonal fruit, was used as a feedstock waste biomass for biochar synthesis through valorization of watermelon rinds. The watermelon biochar (WM-BC) was synthesized through slow pyrolysis at 550°C under anoxic conditions. Langmuir model with R2>99, was found to best fit the adsorption isotherm, and the adsorption kinetics was best described by the pseudo-second-order model. Various characterization tools including FTIR, SEM, BET, XRD, and TEM were used to evaluate the surface morphology of the biochar. The removal efficiency increased from 35% (dosage = 0.4 g), to 81% at WM-BC dosage of 2 g. A maximum adsorption capacity of 115.61 mg/g was found. The results from kinetic and isotherm model model suggested that the adsorption was favorable and multilayer adsorption can be considered. The adsorption mechanism was found to be governed by the co-existing factors such as hydrogen bonding, electrostatic interactions, and aromatic interactions. Results suggest that WM-BC has high potential to be employed as an adsorbent for efficient remediation of methylene blue dyes from aqueous solutions.

Nutritional and Sensory Characterization of Watermelon Rind Powder Incorporated Crackers

Watermelon, is a seasonal fruit with 91% of waterand is relished for its taste, good appeal and nutritional properties. The rind which occupiesa huge volume of the fruit is often disposed off and contributes to a large share from fruit waste. Watermelon rind is known to be a source of moisture, carbohydrate, protein, vitamins, minerals and phytochemicals. This study was framed with the intention of incorporating the wellness of watermelon rind in the commonly consumed snack, crackers. The watermelon rind was dried and powdered by using standard procedures. The powdered rind was incorporated in the ratio of 10%, 20% and 30% to the refined wheat flour and three variations of crackers namely C1, C2 and C3 were formulated. A significant difference (P<0.05) was found in the means of all the organoleptic parameters and the highly accepted variation in terms of organoleptic evaluation namely C3, was further subjected to nutritional evaluation.When compared with the control crackers the watermelon rind flour (30%) incorporated crackers was found to be superior in nutritional aspects.

Comparison of Conventional and Microwave-assisted Extraction of Pectin from Watermelon Rind

Comparison of Conventional and Microwave-assisted Extraction of Pectin from Watermelon Rind

A pectocellulosic bioplastic from fruit processing waste: robust, biodegradable, and recyclable

Recyclable and biodegradable bioplastics made from biomass resources are urgently needed to combat the massive amount plastic packaging waste generated by the food sector. Herein, a novel “top-down” strategy is demonstrated for obtaining high-performance pectocellulosic bioplastics from fruit processing waste, specifically citrus peels rich in pectin and cellulose. The pectin, cellulose and lignin in citrus peels were separated, then the pectin and cellulose components recombined to form a pectin-cellulose film-forming slurry for casting into films. After the cast films had dried, they were then immersed in a CaCl2 solution to crosslink the pectin chains. The obtained pectocellulosic bioplastic films possessed a dense lamellae structure due to inter/intra-molecular entanglement between the cross-liked pectin and cellulose micro/nanofibers, offering excellent mechanical properties, easy recycling and rapid biodegradation. Additionally, this pectocellulosic bioplastic exhibited excellent water stability, water vapor barrier properties, and antioxidant activity. Importantly, the same protocol was applicable for the manufacture of bioplastics from other pectin- and cellulose-rich biomass raw materials (such as watermelon rind, pineapple rind and cantaloupe rind). From both an ecological and economic viewpoint, this biomass-derived bioplastics synthesized in this work offer potential as substitutes for petrochemical-derived plastics in many fields, especially active food packaging.

A Mini Review on Conventional and Alternatives Extraction Methods of Pectin from Watermelon (Citrullus lanatus) Rind

A Mini Review on Conventional and Alternatives Extraction Methods of Pectin from Watermelon (Citrullus lanatus) Rind

Pengaruh Penambahan Air Laut Terhadap Nilai Tegangan Bio Baterai Kulit Semangka (Citrullus Lanatus)

The purpose of this study was to analyze the stress value of a mixture of watermelon rind with mineral water and a mixture of watermelon rind and seawater concerning time. The benefit of this research is to provide information about the stress value of the mixture of watermelon rind with mineral water and to provide information about the stress value of the mixture of watermelon rind and seawater. The method that will be used is experimental by testing its tension using a multimeter. The results obtained in this study are: A mixture of watermelon rind with mineral water produces a voltage value in the range of 568 mV - 4280 mV, but the research data has not shown a pattern. The mixture of watermelon rind with seawater produces a voltage value in the range of 338 mV-4240 mV. At the same time of measurement, the number of cells is proportional to the voltage value. The value of the voltage is inversely proportional to the length of the measurement.
 Keywords: voltage, watermelon, mineral water, sea waters

Formulasi dan Uji Sifat Fisik Sediaan Krim dari Ekstrak Watermelon Rind ((Citrullus lanatus).(Thunb)).

Indonesia has a tropical climate which makes the body produce excess oil. This triggers the occurrence of acne, because it can clog skin pores and cause the formation of bacterial colonies. Watermelon is a fruit that has many health benefits. Generally, people consume the contents and throw away the white flesh and skin (watermelon rind), even though this part has good benefits for the skin because it contains several biochemical compounds that act as antibacterial. One of the preparations used for skin problems is cream. This study aims to produce a formula for the preparation of watermelon rind extract cream that complies with pharmaceutical requirements and is stable in storage. Watermelon rind cream preparation is made with a concentration of watermelon rind extract, namely FI 7.5%; FII 12.5%, and FIII 20%. Finished preparations were tested for physical stability which included organoleptic tests, homogeneity, pH, irritation tests, cream type tests, spreadability and stability tests. The watermelon rind extract cream obtained is green in color, has a distinctive smell of extract and rose oil, is homogeneous, and is of the M/A type. The pH of the watermelon rind extract cream is in a range that is still acceptable to the skin and has good spreadability and does not cause irritation to the skin. During the storage period, the watermelon rind extract cream did not experience physical changes and homogeneity, and did not experience a significant decrease in pH and spreadability with a p-value > 0.05. This shows that the preparation of watermelon rind extract cream meets pharmaceutical requirements and is stable during storage.

Graphene oxide nano-layers functionalized/reduced by L-Citrulline/Pectin bio-molecules for epoxy nanocomposite coating mechanical properties reinforcement

In this work, graphene oxide (GO) was reduced/modified by an eco-friendly route using L-Citrulline molecules extracted from the watermelon rind. Before and after the modification/reduction process, the rGO layers were characterized by different spectroscopy techniques. In addition, the mechanical properties of the epoxy-rGO reinforced coatings were evaluated by tensile and dynamic mechanical thermal analysis (DMTA) tests. The characterization results have demonstrated that the GO nanosheets were successfully reduced/modified by the extracted compounds. DMTA analysis showed that the values of storage modulus at glassy and rubbery regions for the neat epoxy sample incorporated with the rGO nanosheets were increased by about 39 % and 97 %, respectively. Moreover, the glass transition temperature (Tg) was increased from 76.8 °C for the neat epoxy (EP) to 84.0 °C for the EP/modified-reduced GO nanocomposite. Tensile tests showed that the values of tensile strength, maximum strain, elastic modulus, and toughness of the epoxy-based coating were respectively increased by about 142 %, 266 %, 46.7 %, and 388 % after incorporation of the rGO nanosheets compared to the EP sample.

Genetic Mapping of a Candidate Gene ClIS Controlling Intermittent Stripe Rind in Watermelon

Rind pattern is one of the most important appearance qualities of watermelon, and the mining of different genes controlling rind pattern can enrich the variety of consumer choices. In this study, a unique intermittent rind stripe was identified in the inbred watermelon line WT20. The WT20 was crossed with a green stripe inbred line, WCZ, to construct F2 and BC1 segregating populations and to analyze the genetic characterization of watermelon stripe. Genetic analysis showed that the intermittent stripe was a qualitative trait and controlled by a single dominant gene, ClIS. Fine mapping based on linkage analysis showed that the ClIS gene was located on the 160 Kb regions between 25.92 Mb and 26.08 Mb on watermelon chromosome 6. Furthermore, another inbred watermelon line with intermittent stripe, FG, was re-sequenced and aligned on the region of 160 Kb. Interestingly, only two SNP variants (T/C, A/T) were present in both WT20 and FG inbred lines at the same time. The two SNPs are located in 25,961,768 bp (T/C) and 25,961,773 bp (A/T) of watermelon chromosome 6, which is located in the promoter region of Cla019202. We speculate that Cla019202 is the candidate gene of ClIS which controls the intermittent stripe in watermelon. In a previous study, the candidate gene ClGS was proved to control dark green stripe in watermelon. According to the verification of the two genes ClIS and ClGS in 75 watermelon germplasm resources, we further speculate that the ClGS gene may regulate the color of watermelon stripe, while the ClIS gene regulates the continuity of watermelon stripe. The study provides a good entry point for studying the formation of watermelon rind patterns, as well as providing foundation insights into the breeding of special appearance quality in watermelon.

Extraction and characterization of pectin from watermelon rind using acetic acid

In this work, watermelon rind was used for extraction of pectin with acetic acid solution. The effects of pH, temperature and extraction time on the pectin yield were investigated. Response surface based on Box-Behnken model was employed to optimize the extraction parameters. The model shows an optimum pectin yield of 18.21%, which is in agreement with the value confirmed through experiment (18.20%). The moisture content, ash content, degree of esterification, degree of methylation, equivalent weight, methoxy content, and anhydrouronic acid of the extracted pectin were determined. The values of the moisture content, ash content, degree of esterification, degree of methylation, equivalent weight, methoxy content, anhydrouronic acid are 8.42%, 5.1%, 57.30%, 23.5%, 983.9 mg/mol, 7.3% and 72.36%, respectively. The results show watermelon peel can be an alternative source for pectin production with reasonable pectin yield and pectin quality.

Watermelon rind derived carbon monolith as potential regenerable adsorbent for perchlorate

Present work describes the preparation of porous carbon block from watermelon rind, as an efficient adsorbent for perchlorate contaminant. Freeze drying, followed by carbonization yielded a highly mesopore dominated porous carbon block, will suitable for water purification. Carbon block (WRPC-Mag), with high surface area of 867 m2g−1 showed highest ever reported perchlorate removal efficiency of 1496 mg g−1. The highest efficiency is attributed to the presence of naturally occurring hetero atoms present in the raw material, which act as in-situ chemical activating agent. Easy recovery of spent adsorbent is achieved by magnetic functionalization of carbon block. Watermelon rind derived carbon block is an efficient, economic, handy and novel candidate for perchlorate removal.

Tailoring structural, rheological and gelling properties of watermelon rind pectin by enzymatic treatments

In this work, pectin extracts from watermelon rind (WRP) were enzymatically treated to evaluate their potential for preparing hydrogels with the addition of CaCl 2 . Based on a previous work, two different conditions were selected to obtain WRP extracts according to the 1) highest yield (OP) or 2) highest yield without negatively affecting the branching and native structure of pectin (OPA). Firstly, both WRP extracts were enzymatically modified using different treatments (de-esterification and/or de-branching of galacturonic and arabinose side chains, and deproteinization), and their impact on the esterification degree, monosaccharide composition and changes on their structural properties (linearity and branching degree) were deeply analysed. Then, the effect of the structural properties of the resulting pectin on the rheological behaviour and nanostructure of the hydrogels was investigated. The presence of long branched side chains and high methyl-esterified galacturonic acid chains promoted the formation of weaker hydrogels whereas de-esterification of the original pectin enabled intermolecular association giving rise to stronger hydrogels with the formation of ordered and densely packed structures (as deduced from SAXS results). However, the presence of small arabinogalactans side chains in the de-branched and de-esterified pectin extracts acted as reinforcement agents, inducing the formation of more densely packed networks and stronger hydrogels than their less-branched counterpart. These results demonstrated the impact of the pectin structure on the hydrogel-forming capacity. • Two watermelon rind pectin extracts were enzymatically modified. • Enzymes acting on neutral sugar side chains did not significantly de-branch the pectin structure. • Weaker gels were obtained when pectins were treated with de-branching enzymes. • Stronger gels were produced when pectin was de-esterified. • The strongest gels were produced when de-esterification and de-branching enzymes were combined.

Fungal Production of Cellulase Using Fruit Waste as Economical Growth Substrates

Background: Vegetables and fruits are playing an important role in human life and diet. For eco-friendly usage the fruit peel wastes can be used as nutrients for microorganisms and animals as they consist of various growth promoting factors. Cellulolytic enzymes convert cellulose into simpler sugars. Due to suitable cellulase titers and rapid growth bacteria and fungi are becoming choice of interest. Aim: Production of fungal cellulase by using different types of fruit wastes. Method:This descriptive study was conducted by collecting the Fruit wastes (mango peels, melon peels, orange peels and watermelon rind) from fruit processing shops and transported to Applied and Environmental Microbiology laboratory.Inoculum was prepared by using basal medium and fruit peel powder.Descriptive statistical analysis of data will be performed. One way Analysis of Variance (ANOVA) will be applied for comparing mean values among species using Minitab 16. P < 0.05 will be considered significant. Result: The statistical analysis showed that in solid state fermentation the enzyme summary within 10 days was (181.32±0.00 μg/ml/min) after every 24 hour was (9.40±1.22μg/ml/min) and (0.39±0.05μg/ml/min) after every 1 hour and (0.01±0.00μg/ml/min) at 1 minute. The statistical analysis showed that in sub-merged fermentation the enzyme summary within 10 days was 191.83±4.96 after every 24 hour was (7.12±0.76μg/ml/min) and (0.30±0.03μg/ml/min) after every 1 hour and (0.0.00±0.00 μg/ml/min) at 1 minute. Conclusion: The present study clearly indicates the potential of Rhizopussp as the best producer of cellulolytic enzymes. Regarding the substrate fruit peels (mango peels, melon peels, orange peels, and watermelon rind) can be used for the efficient production of cellulase. Keywords: Rhizopus, cellulolytic enzymes, fruit peels, fungal production.

Customized oxygen-rich biochar with ultrahigh microporosity for ideal solid phase microextraction of substituted benzenes

The synergistic effect of high microporosity and abundant heteroatoms is important for improving the performance of biochar in various fields. However, it is still challenging to create enough micropores for biochar, while simultaneously retaining the heteroatoms from biomass. A series of biochar with variable microstructures was successfully prepared by carbonization and following ball milling on lotus pedicel (LP), watermelon rind (WR), and litchi rind (LR). The pore structures and heteroatoms of biochar were characterized in detail. Notably, high microporosity could be realized by the carbonization of LR, and further ball milling resulted in a higher microporous surface area (1323.4 m2·g−1) and richer oxygen. Furthermore, the obtained biochar was fabricated as solid phase microextraction (SPME) coatings with uniform morphologies and similar thicknesses to deeply investigate the relationships between the microstructures and extraction performance. The best performance was demonstrated by the LR800BM, with enrichment factors from 1780 to 155,217. Finally, it was coupled with gas chromatography–mass spectrometry (GC–MS) to develop an analytical method with a wide linear range (1–50,000 ng·L−1), low limits of detection (0.10–1.4 ng·L−1), good repeatability (0.83 %–7.5 %) and reproducibility (4.2 %–8.9 %). This work provides valuable insights into the structure-performance relationship of biochar, which is important for the design of high-performance biochar-based adsorbents and their applications in the environment.

Bioethanol and biomethane production from watermelon waste: A circular economy strategy

In the present study, bioethanol and biogas were produced from watermelon waste aiming at the integral use of residual biomass in a circular economy context. Watermelon pulp was processed and used as the culture medium for ethanol production with the yeast Wickerhamomyces sp. UFFS-CE-3.1.2 and watermelon rinds were used for biochemical biogas production (BBP) assays. For the ethanol production step from watermelon pulp, the results demonstrate that there was no requirement to supplement the medium with nitrogen sources to achieve satisfactory yields and cell viability. With this, a sequential batch configuration with cell recycling was conducted for thirty cycles, with fermentation yields of around 90% during all recycling, high cell density and viability, and reduced fermentation time from 9 h to 3 h. The results of the biogas production step from watermelon rinds indicate that the biomass performed well, with biogas and methane production of 581 ± 11 mLN·gVS and 290.63 ± 5.63 mLCH4·gVS, respectively, and energetic potential of 15,461.54 kJ·kgbiomass−1. Our data provide a perspective on using watermelon waste for biofuel production to reduce the environmental impacts of this biomass disposal, thus contributing to the circular economy and the advances in the field of renewable energy.

Bio-mass derived hierarchically porous and high surface area carbon as an efficient sulfur host for lithium-sulfur batteries

Lithium–sulfur (Li-S) batteries are attractive candidates for electric vehicles and grid storage applications due to their high energy density than Li-ion batteries. Development of high energy Li-S batteries employing eco-friendly, and bio-waste derived materials will further increase the sustainability of the energy storage devices. Herein, we utilize porous carbon derived from waste watermelon rind for Li-S battery application. The porous carbon with hierarchal architecture, and functional heteroatoms can efficiently infiltrate the sulfur cathode and overcomes the major challenges in the Li-S battery, namely (i) poor electronic conductivity of sulfur cathode, and (ii) dissolution of long-chain polysulfides. The Li-S cell with a sulfur-infiltrated porous carbon delivered a high initial discharge capacity of 1176 mAh g−1 at 0.5C rate with a low capacity fading rate of 0.057% over 500 cycles. The strong carbon framework can accommodate the volume changes during the sulfur conversion reaction, and the unoccupied pores in porous carbon can function as polysulfide reservoir to efficiently trap polysulfide migration to achieve a high stability. The highly inter-connected hierarchical pores further facilitated a faster electronic and ionic transport to achieve a high rate performance, higher than pristine sulfur cathode. These results demonstrate the potential to develop high-performance energy storage devices using eco-friendly and renewable materials for electric vehicles and other energy storage systems.

Pectin-based aerogel particles for drug delivery: Effect of pectin composition on aerogel structure and release properties

In this work, nanostructured pectin aerogels were prepared via a sol-gel process and subsequent drying under supercritical conditions. To this end, three commercially available citrus pectins and an in-house produced and enzymatically modified watermelon rind pectin (WRP) were compared. Then, the effect of pectin's structure and composition on the aerogel properties were analysed and its potential application as a delivery system was explored by impregnating them with vanillin. Results showed that the molecular weight, degree of esterification and branching degree of the pectin samples played a main role in the production of hydrogels and subsequent aerogels. The developed aerogel particles showed high specific surface areas (468–584 m2/g) and low bulk density (0.025–0.10 g/cm3). The shrinkage effect during aerogel formation was significantly affected by the pectin concentration and structure, while vanillin loading in aerogels and its release profile was also seen to be influenced by the affinity between pectin and vanillin. Furthermore, the results highlight the interest of WRP as a carrier of active compounds which might have potential application in food and biomedical areas, among others.

The effect of microencapsulated watermelon rind (Citrullus lanatus) and beetroot (Beta vulgaris L.) ingestion on ischemia/reperfusion-induced endothelial dysfunction: a randomised clinical trial.

Endothelial dysfunction is commonly associated with a cardiovascular event, such as myocardial infarction. Myocardial infarction is marked by an ischemia/reperfusion (IR) phenomenon associated with endothelial dysfunction, contributing even more to future cardiovascular events. Although the supplementation with L-citrulline and nitrate from watermelon and beetroot have been used to improve vascular function, the effect of microencapsulated watermelon rind (WR) or its co-ingestion with beetroot (WR + B) on endothelial IR injury has not been addressed. Therefore, this study aimed to investigate the effect of a single dose of WR and WR + B on IR-induced macro-and microvascular dysfunction. In a randomized, crossover, placebo-controlled study, 12 volunteers underwent macro (flow-mediated dilation) and microvascular (muscle oxygen saturation) assessment and blood collection (to measure L-citrulline, L-arginine, nitrate and nitrite) before and after 20 min of blood occlusion in WR, WR + B and placebo conditions. Prolonged ischemia induced endothelial dysfunction in the macro but not in the microvasculature. The WR and WR + B supplementation significantly restored FMD after IR injury compared to the placebo (p < 0.05). However, there was no significant difference between WR and WR + B in the macrovascular function (p > 0.05). Plasma L-citrulline, L-arginine, nitrate, and nitrite significantly increased (p > 0.05) after WR and WR + B supplementation compared to the placebo. A single dose of WR and WR + B effectively minimizes IR-induced macrovascular endothelial dysfunction in healthy individuals. Beetroot co-ingestion with watermelon did not provide an additional effect of endothelial dysfunction induced by IR (NCT04781595, March 4, 2021).