Antioxidant properties and phytochemicals of three brown macro algae from the Dardanelles (Çanakkale) Strait

A.K. Ilknur1*, G. Turker2

1Department of Aquaculture, Faculty of Marine Sciences and Technology, Canakkale Onsekiz Mart University, 17100 Canakkale, Turkey 2Department of Food Technology, Canakkale School of Applied Sciences, Canakkale Onsekiz Mart University, 17100 Canakkale, Turkey

((Manuscript received 17 May 2018; accepted for publication 26 August 2018))

Abstract. This study was conducted to determine antioxidant properties and phytochemicals of brown algae Scytosiphon lomentaria (Lyngbye) Link, Cystoseira barbata (Stackhouse) C. Agardh, and Padina pavonica (Linnaeus) Thivy, collected from the Dardanelles (Çanakkale) Strait, Turkey, in February 2018. The antioxidant activity, total carotenoids, condensed tannins, and total content of phenolics and flavonoids in ethanol extracts were quantified. P. pavonica showed the highest antioxidant potential as well as the maximum content of phenolics and carotenoids. The total flavonoid contents changed from 1375.43±2.37 μg/g Ext. (C. barbata) to 2250.92±46.60 μg/g Ext. (S. lomentaria). The highest condensed tannins were found in C. barbata. According to results obtained, C. barbata, S. lomentaria and P. pavonica possess antioxidant activity and could be used in the food and feed industries.

Influence of different factors on tannins and flavonoids extraction of some thyme varieties representatives of thymol, geraniol and citral chemotype

G. Zhekova, D. Pavlov
Abstract. Three chemotype thyme – thymol “Nemska zima”, citral – “Slava” and geraniol – “Pagane” with purpose obtaining of extract for cosmetics and pharmaceutics application were investigated in the present work. The extraction was carried out as stationary periodical process with ratio between dry herb and solvent 1:10, temperature from 20ºC to 60ºC, duration from 1 to 5 hours with solvents – 60% ethanol and 85% glycerin. The obtained extracts were determined the content of tannins and flavonoids. The data were presented as four factors analysis – type of solvent, thyme variety, temperature and duration of process. The results showed that the thyme variety has the strongest influence on extracted tannins and flavonoids, followed by solvent type, temperature and duration of the process. The extract obtained from variety “Nemska zima” has the highest content of derived substances followed by “Slava” and “Pagane”. The ethanol derives tannins and flavonoids in bigger extent than the glycerin. The differences between the two solvents are most significant at temperature 20ºC.