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Öğe Comparison of Phenolic Profile and Antioxidant Properties of Pulp and Seeds of Two Different Grapes Types (Vitis vinifera L. and Vitis labrusca L.) Grown in Anatolia: The Amount of Resveratrol of Grape Samples(Springer Science and Business Media Deutschland GmbH, 2023) Kavgacı, Merve; Yukunc, Gulsah Okumus; Keskin, Merve; Can, Zehra; Kolaylı, SevgiBackground: Grape is the most widely cultivated fruit all over the World and it is both food and a good source of antioxidants. The fruit is rich in phytochemicals and its seed is especially a source for resveratrol, a stilbene that shows health promoting effect. Objective: In this study, phenolic profile and antioxidant properties of eight grape cultivars with two species cultivated in Turkey were compared. Isabella, Razaki, Alphonse Lavalleé, Red Globe and Emir cultivars were used. Methods: Total phenolic substance (TPS), total flavonoid substance (TFS), total antioxidant capacity (FRAP) and phenolic compositions of the pulp and the seeds were determined. Phenolic composition of grapes were found by using HPLC-UV. Results: The results showed that total phenolic substances and total antioxidant capacities were richer in the seeds than in the pulps. Catechin and epicatechin are major phenolic compounds in the grape seeds, and chrysin, pinocembrin, resveratrol, luteolin and caffeic acid phenethyl ester (CAPE) were detected in the pulp as major. Resveratrol varied from 4.50 to 101.89 mg/100 g, while was equally in both the seed and pulp. It was found that all grape samples were rich in phenolic compounds and had antioxidant activity. Conclusion: It was clear that antioxidant capacity and phenolic profile of samples changes according to grape species and cultivars. © 2023, The Tunisian Chemical Society and Springer Nature Switzerland AG.Öğe Green Synthesis, Characterization, Antioxidant, Antibacterial and Enzyme Inhibition Effects of Chestnut (Castanea sativa) Honey-Mediated Silver Nanoparticles(Mdpi, 2023) Keskin, Merve; Kaya, Gulsen; Bayram, Sinan; Kurek-Gorecka, Anna; Olczyk, PawelIn this study, chestnut honey-based silver nanoparticles (CH-AgNPs) were synthesized at different temperatures (30, 60 and 90 degrees C) and these nanoparticles were characterized by different techniques such as UV-vis spectrophotometer, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The DPPH free radical scavenging assay was used to determine the antioxidant activity of the obtained nanoparticles. The inhibition effects of these nanoparticles for some clinically important enzymes such as myeloperoxidase and collagenase were investigated. In addition, the disk diffusion method (DDM), agar well diffusion (AWD), and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) techniques were used to determine the antibacterial activity of CH-AgNPs. In honey-based silver nanoparticle production processes using green synthesis, it was determined that the nanoparticle sizes decreased from 55 to 27 nm with an increase in temperature. In addition, it was determined that the rate of inhibition of myeloperoxidase (36.4% to 34.0%) and collagenase enzymes (74.2% to 68.7%) increased with a decrease in particle size. As a result of the antibacterial activity tests, it was observed that CH-AgNPs have antibacterial activity against all target pathogens including Gram-positive and Gram-negative bacteria. The obtained results show that CH-AgNPs produced using chestnut honey have the potential to be used in fields such as medicine, pharmacy and cosmetic technology.Öğe Honey: Determination of volatile compounds, antioxidant and antibacterial activities(Czech Academy Agricultural Sciences, 2021) Karlidag, Semiramis; Keskin, Merve; Bayram, Sinan; Mayda, Nazli; Ozkok, AsliHoney is an important functional food for human health and nutrition that is collected by honey bees and stored in the honeycombs. In this study, total phenolic content, antioxidant activity and volatile compounds of 13 different honey samples collected from various districts of Malatya province were investigated. As a result of this study, it was determined that the total phenolic content varied between 8.50 mg GAE 100 g(-1) and 73.90 mg GAE 100 g(-1) and it was observed that the honey samples were rich in aldehydes, aliphatic acid and esters, alcohols, hydrocarbons, carboxylic acid esters, ketones, terpenes, fatty acids and esters. In addition, the antibacterial effects of honey samples were determined against 18 different pathogenic bacteria using agar well diffusion (AWD) method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). In AWD assay, it was recorded that inhibition zone diameters varied between 9 mm and 14 mm and honey samples were found to have a partial inhibitory effect against selected target pathogens.Öğe Palynological, chemical, antimicrobial, and enzyme inhibition properties of Cannabis sativa L. propolis(Springer, 2023) Ozkok, Asli; Karlidag, Semiramis; Keskin, Merve; Bayram, Sinan; Keskin, Saban; Karabulut, Ercan; Cicek, FevziIn this study, both chemical characterization and biological activities of propolis samples obtained from Cannabis sativa L. (cannabis, hemp, marijuana) isolated colonies (research group) and obtained from colonies at a distance where the bee cannot fly to the isolation area (control group) were determined. Palynological analyses of propolis samples obtained from the research and control group colonies were made and the botanical origin of the cannabis plant and other plants in the research area and the plants in the control group were determined. Bioactive component analysis of propolis extracts was determined by the GC-MS technique. The inhibition effect of propolis samples on some enzymes of medical importance and their antimicrobial effects against many pathogenic microorganisms were also investigated. Palynological analyses showed that honey bees prefer cannabis plants (11.11%) when collecting propolis, and the dry matter percentage (94.6 +/- 1.8%), balsam (46.2 +/- 5.2%), and wax content (4.8 +/- 0.5%), total phenolic (26.44 +/- 1.08 mg GAE/mL) and total flavonoid (2.03 +/- 0.11 mg QE/mL) content and antioxidant capacity (88.16 +/- 2.27 mu M FeSO4 center dot 7H(2)O/mL(-1)) of the research group propolis samples containing hemp were found to be higher than the control group. Also, it was determined that the research group propolis sample contains cannabinoid derivatives (cannabidivarinic acid, 0.29%; delta (1)-tetrahydrocannabinolic acid, 0.59%; cannabidiolic acid, 0.48%), which are active compounds of the cannabis plant. Also, a high inhibition effect was detected on some enzymes of medical importance in propolis samples obtained from cannabis group colonies. In addition, the research group propolis samples also showed a high antimicrobial effect against many pathogenic microorganisms.
