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While olive fruit has been processed and consumed as food in different ways for centuries; Its leaves are also used for their therapeutic effects. Today, olive leaf, which has been the subject of many studies in terms of its health benefits, is most commonly consumed as tea. In this study, particle size and different infusion temperatures were used to determine some physical properties of infused tea, total phenolic substance (Folin-Ciocalteu method) and flavonoid amount, antioxidant capacity (ABTS•+, DPPH, FRAP) and its effects on sensory properties were investigated. Particle size and infusion methods had a statistically significant effect on all analyzed properties (p<0.01). It has been determined that grinding olive leaves increases the L* and b* values and decreases the a* value in the infusion. It was determined that the total phenolic substance amounts of infused teas varied between 128.87 and 58.04 mg GAE/L, and the total flavonoid substance amount was highest in hot infused tea (491.54 mg QE/L). It has been determined that teas infused from ground leaves have higher antioxidant activity than those infused whole. In sensory evaluation, it was determined that the overall acceptability of teas infused from whole leaves on ice and at room temperature was highest. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of the Institute of Science & Technology / Iğdır Üniversitesi Fen Bilimleri Enstitüsü Dergisi is the property of Igdir University, Institute of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, some physiochemical properties (color, pH, total and soluble solid, titratable acidity, glucose, fructose and total sugar content, water activity, hydroxymethyl furfural (5-HMF) as well as antioxidant activity and phenolic composition of traditionally produced rosehip (Rosa canina L.), cornelian cherry (Cornus mas L.), blackthorn (Pyrus elaeagrifolia) and Ahlat pear (Pyrus elaeagrifolia) marmalades were determined. In research, the following data were determined that all marmalade samples' total and water soluble dry matter contents were over 55%; water activity and total sugar contents were over 0.79 and 47 g/100g and HMF contents were found between 10.95 and 1094.11 mg/kg. All samples contained gallic acid, catechin, epicatechin, vanillin, chlorogenic acid, caffeic acid, coumaric acid, p-coumaric acid, hesperidin, routine, ellagic acid and quercetin in different ratios. Phenolic substance values of marmalade samples were between 64.67-205.75 µg GAE/g. The highest DPPH radical scavenging activity belonged to the cornelian cherry marmalade (%3.72±0.09). Because of the high phenolic composition and antioxidant activities of rosehip, blackthorn, cornelian cherry and Ahlat pear marmalades besides their significant health benefits may be used for developing functional foods. High HMF contents in blackthorn and Ahlat pear marmalades could be due to long processing time and boiling process at high temperature during conventional production, and consumers should be aware of this problem. [ABSTRACT FROM AUTHOR]