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16 pages, 2239 KiB

Open AccessArticle

Synthesis of Silver Nanoparticles from Bitter Melon (Momordica charantia) Extracts and Their Antibacterial Effect

by Nanh Lovanh, Getahun Agga, Graciela Ruiz-Aguilar, John Loughrin and Karamat Sistani

Microorganisms 2025, 13(8), 1809; https://doi.org/10.3390/microorganisms13081809 - 2 Aug 2025

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We utilized silver nanoparticles synthesized from bitter melon (Momordica charantia) extracts for testing against the common agricultural pathogen Escherichia coli. The synthesized nanoparticles were characterized and confirmed as silver nanoparticles by using ultraviolet spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy analysis. The results show that AgNPs were effective against E. coli ATCC25922 strain. The AgNPs had an increased potency against the E. coli strain in optimum culture media compared to silver ions alone. AgNP-treated cultures achieved a kill percentage of 100% in less incubation time and at a lower dosage than those treated with silver ions alone. The powder form of the AgNPs also showed remarkable potency against E. coli in solution. Based on these findings, the current method is suitable for the industrial-scale production of AgNPs from a commonly available edible plant with known medicinal benefits in the fight against foodborne pathogens, including antibiotic-resistant strains. Full article

(This article belongs to the Special Issue Bacterial and Antibiotic Resistance in the Environment (Second Edition))

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12 pages, 1981 KiB

Open AccessFeature PaperArticle

Self-Assembled Fullerene Crystals as Excellent Aromatic Vapor Sensors

by Natsumi Furuuchi, Rekha Goswami Shrestha, Yuji Yamashita, Tetsuji Hirao, Katsuhiko Ariga and Lok Kumar Shrestha

Sensors 2019, 19(2), 267; https://doi.org/10.3390/s19020267 - 11 Jan 2019

Cited by 41 | Viewed by 4573

Abstract

Here we report the aromatic vapor sensing performance of bitter melon shaped nanoporous fullerene C₆₀ crystals that are self-assembled at a liquid-liquid interface between isopropyl alcohol and C₆₀ solution in dodecylbenzene at 25 °C. Average length and center diameter of the crystals were ca. 10 μm and ~2 μm, respectively. Powder X-ray diffraction pattern (pXRD) confirmed a face-centered cubic (fcc) structure with cell dimension ca. a = 1.4272 nm, and V = 2.907 nm³, which is similar to that of the pristine fullerene C₆₀. Transmission electron microscopy (TEM) confirmed the presence of a nanoporous structure. Quartz crystal microbalance (QCM) results showed that the bitter melon shaped nanoporous C₆₀ performs as an excellent sensing system, particularly for aromatic vapors, due to their easy diffusion through the porous architecture and strong π–π interactions with the sp²-carbon. Full article

(This article belongs to the Section Biosensors)

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20 pages, 1042 KiB

Open AccessArticle

Optimising the Encapsulation of an Aqueous Bitter Melon Extract by Spray-Drying

by Sing Pei Tan, Tuyen Chan Kha, Sophie Parks, Costas Stathopoulos and Paul D. Roach

Foods 2015, 4(3), 400-419; https://doi.org/10.3390/foods4030400 - 9 Sep 2015

Cited by 42 | Viewed by 8590

Abstract

Our aim was to optimise the encapsulation of an aqueous bitter melon extract by spray-drying with maltodextrin (MD) and gum Arabic (GA). The response surface methodology models accurately predicted the process yield and retentions of bioactive concentrations and activity (R² > 0.87). The optimal formulation was predicted and validated as 35% (w/w) stock solution (MD:GA, 1:1) and a ratio of 1.5:1 g/g of the extract to the stock solution. The spray-dried powder had a high process yield (66.2% ± 9.4%) and high retention (>79.5% ± 8.4%) and the quality of the powder was high. Therefore, the bitter melon extract was well encapsulated into a powder using MD/GA and spray-drying. Full article

(This article belongs to the Special Issue Food Modelling)

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16 pages, 612 KiB

Open AccessArticle

An Optimised Aqueous Extract of Phenolic Compounds from Bitter Melon with High Antioxidant Capacity

by Sing Pei Tan, Costas Stathopoulos, Sophie Parks and Paul Roach

Antioxidants 2014, 3(4), 814-829; https://doi.org/10.3390/antiox3040814 - 2 Dec 2014

Cited by 62 | Viewed by 12740

Abstract

Bitter melon (Momordica charantia L.) is a tropical fruit claimed to have medicinal properties associated with its content of phenolic compounds (TPC). The aim of the study was to compare water with several organic solvents (acetone, butanol, methanol and 80% ethanol) for its efficiency at extracting the TPC from freeze-dried bitter melon powder. The TPC of the extracts was measured using the Folin-Ciocalteu reagent and their antioxidant capacity (AC) was evaluated using three assays. Before optimisation, the TPC and AC of the aqueous extract were 63% and 20% lower, respectively, than for the best organic solvent, 80% ethanol. However, after optimising for temperature (80 °C), time (5 min), water-to-powder ratio (40:1 mL/g), particle size (1 mm) and the number of extractions of the same sample (1×), the TPC and the AC of the aqueous extract were equal or higher than for 80% ethanol. Furthermore, less solvent (40 mL water/g) and less time (5 min) were needed than was used for the 80% ethanol extract (100 mL/g for 1 h). Therefore, this study provides evidence to recommend the use of water as the solvent of choice for the extraction of the phenolic compounds and their associated antioxidant activities from bitter melon. Full article

(This article belongs to the Special Issue Analytical Determination of Polyphenols)

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16 pages, 2564 KiB

Open AccessArticle

Effect of Superfine Grinding on Antidiabetic Activity of Bitter Melon Powder

by Ying Zhu, Ying Dong, Xiwen Qian, Fengjie Cui, Qin Guo, Xinghua Zhou, Yun Wang, Yi Zhang and Zhiyu Xiong

Int. J. Mol. Sci. 2012, 13(11), 14203-14218; https://doi.org/10.3390/ijms131114203 - 2 Nov 2012

Cited by 61 | Viewed by 9489

Abstract

The antidiabetic activities of bitter melon powders produced with lyophilization/superfine grinding and hot air drying/normal grinding were investigated in vivo for selecting a suitable bitter melon processing procedure. After a five-week treatment, bitter melon lyophilized superfine grinding powder (BLSP) had a higher antidiabetic activity with reducing fasting blood glucose levels from 21.40 to 12.54 mmol/L, the serum insulin levels from 40.93 to 30.74 mIU/L, and restoring activities of SOD compared with those in the bitter melon hot air drying powder (BAP) treated group. Furthermore, BLSP protected pancreatic tissues including islet beta cells and reduced the loss of islet cells. Combined with the difference of compositions in BLSP and BAP, it could be concluded that superfine grinding and lyophilization processes were beneficial for presenting the antidiabetic activity, which will provide a reference for direct utilization of bitter melon as a suitable functional food to relieve symptoms of diabetes. Full article

(This article belongs to the Section Biochemistry)

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