Browsing by Author "Yavas, Berfin"

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Antioxidant Activity, Total Phenolic Content, and Volatile Component Profiles of Propolis From Eight Turkish Regions
(Wiley-v C H verlag Gmbh, 2025) Basturk, Ayhan; Yavas, Berfin
This study aimed to evaluate the volatile component profiles and antioxidant activities of propolis samples collected from eight regions of T & uuml;rkiye. The total phenolic content of propolis samples was found to vary between 5333 and 36967 mg GAE/100 g. 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity of the samples varied from 10.9% to 92.2%, while 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activity varied from 193.8 to 1026.0 mu mol Trolox/g. Six of the eight samples exhibited higher antioxidant activities than butylated hydroxytoluene. The predominant volatile components identified in the majority of the propolis samples were alpha-pinene, limonene, bornyl acetate, caryophyllene, alpha-humulene, delta-cadinene, isopentyl acetate, acetic acid, nonanal, m-cymene, and pinocarvone. Principal component analysis (PCA) and hierarchical cluster analyses were applied to the GC-MS data to investigate the trends and clustering in the propolis samples. The propolis samples were divided into four groups using cluster analysis. In the PCA, the first two factors represented 56.39% of the variance. These findings revealed that Turkish propolis has significant antioxidant properties and also contains important volatile compounds. Consequently, Turkish propolis could be considered a potential candidate for incorporation into pharmaceutical and food products.
Identification of Volatile Compounds and Evaluation of Certain Phytochemical Properties of Turkish Propolis
(Wiley, 2024) Yavas, Berfin; Basturk, Ayhan
The purpose of this study was to assess volatile component profiles and the antioxidant activity of propolis samples from eight different locations in T & uuml;rkiye. alpha-Pinene, beta-pinene, 3-carene, limonene, 2-acetylfuran, benzaldehyde, acetic acid, benzoic acid, longifolene, isopentyl acetate, m-cymene, styrene, and delta-cadinene were the most common volatile components found in the most of propolis samples. Principal component analysis (PCA) and hierarchical cluster analysis were performed on the gas chromatography-mass spectrometry (GC-MS) data to identify trends and clusters in the propolis samples. As a result of the PCA, the common components in all propolis were m-cymene, decanal, alpha-pinene, limonene, pinocarvone, benzaldehyde, and butanoic acid. The samples had 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) inhibition activity ranging from 19.2% to 92.5% and 2,2 '-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) values ranging from 480 to 1370 mu M trolox/g extract. The total phenolic content (TPC) ranged from 10,900 to 34,033 mg GAE/100 g. Compared with butylated hydroxytoluene (BHT) (control), all but one of the propolis samples exhibited higher DPPH activity. In addition, ABTS levels of propolis extracts were higher than those of BHT. These results unequivocally show that Turkish propolis has remarkable antioxidant qualities, which makes it a viable option for addition to food and medicine products. The total phenolic content (TPC) of the Turkish propolis under investigation was generally high. Compared to butylated hydroxytoluene (BHT), six of the eight samples had greater antioxidant activity. Propolis from various parts of Turkey contains 61 different components. Principal component and hierarchical cluster analyses were performed on the propolis samples.image
Improving Sunflower Oil Stability With Propolis: a Study on Antioxidative Effects of Turkish Propolis During Accelerated Oxidation
(Wiley, 2024) Basturk, Ayhan; Yavas, Berfin
Propolis, a natural resinous substance collected by bees, is known for its potent antioxidant properties. This study investigates the antioxidant activities and total phenolic contents of propolis samples from 16 provinces of T & uuml;rkiye and their effects on the oxidative stability of sunflower oil. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) inhibition was in the range of 28.1%-92.5% in thirteen propolis samples, whereas this rate was 24.5% in butylated hydroxytoluene (BHT). Although 2,2 '-azino-bis(3-ethylbenzotiazolin-6-sulfonic acid) (ABTS) value was 224 mu mol trolox/g in BHT, this value was in the range of 262-1370 mu mol trolox/g in propolis samples, except for one. Propolis methanol extracts 13 applied to sunflower oil at a concentration of 1000 ppm were more efficient than BHT added at 200 ppm for inhibiting the production of peroxide value (PV). Similarly, most propolis extracts (1000 ppm) demonstrated antioxidant activity against the production of p-anisidine (p-AV) in sunflower oil under accelerated oxidation conditions. It was determined that Turkish propolis had strong antioxidant properties and delayed oxidation and may be utilized commercially in the food sector to delay the oxidation of fats and oils.