Nuraniye Eruygur

The Effect of the Plant Age and Growth Period on the Nutritional Substance, Chlorophyll and Steviol Glycoside Rates in Stevia (Stevia Rebaudiana Bertoni) Leaves

ABSTRACT Stevia (Stevia rebaudiana Bertoni) is a perennial and subshrub herb of the Asteraceae family, which originates from South America. Stevia has long been used as a sweetener and herbal medicine throughout the world. The most important feature of stevia is its sweetness with zero calories. This natural feature of Stevia is of utmost importance to everyone, especially those with diabetes and those who diet. In this study, samples were taken from Stevia rebaudiana plants of different ages (2, 3 and 4 years) in different growth periods (H1: 1 July, H2: 1 August, H3: 1 September and H4: 1 October) and an evaluation was made on the nutritional content values, the chlorophyll and sugar rates found in these samples according to the age and growth period of the plant. It was determined that the age of the plant and the harvesting period had an effect on the macro-micro nutritional elements, and chlorophyll and steviol glycoside rates contained in the stevia plant. In addition, as a result of correlation analysis, significant correlations were determined between the parameters measured in the plant. The results of the study demonstrated that in the cultivation of stevia, the best values were obtained from plants that were 3 years old and harvested in July.

Modeling of Total Phenolic contents in Various Tea samples by Experimental Design Methods

Abstract Tea, from the old ages to the day, is widely consumed both for enjoyment and health care due to its positive effects. The consumption of these products is increasing day by day as a result of the clear presentation of the fact that tea contains high amount of antioxidant substances (such as phenolic compounds), which is important in prevention and treatment of diseases. Tea beverage is a very important source of polyphenols. In this study, phenolic content and antioxidant capacity of different tea species were calculated by modeling with experimental design method. In the experimental part, polyphenol content was determined using the Folin-Ciocalteu method. The total amount of phenolic substance content was examined by Box-Behnken design and response surface method on black tea, green tea and white tea on different extraction temperature, extraction time and solid / liquid ratio. Solid / liquid ratio was found to be the most important parameter in terms of polyphenol content extraction from different tea samples. The highest polyphenol amount (411.762 mg gallic acid / mL) was found in green tea. To the best of our knowledge, this is the first data presenting comparatively study the effect of extraction condition on amounts of phenolic compounds from different tea samples.

A study on the antioxidant, antimicrobial and cytotoxic activity of Thymbra spicata L. var. spicata ethanol extract

Department of Pharmacognosy, Cumhuriyet University Faculty of Pharmacy Sivas; Turkey Department of Pharmaceutical Microbiology, Cumhuriyet University Faculty of Pharmacy Sivas; Turkey Department of Biochemistry, Adnan Menderes University School of Medicine Aydin; Turkey Corresponding author: Nuraniye Eruygur, Department of Pharmacognosy, Cumhuriyet University Faculty of Pharmacy, Sivas; Turkey E-mail: neruygur@cumhuriyet.edu.tr; nuraniye58@gmail.com Received/Accepted: June 30, 2017 / August 23, 2017 Conflict of interest: There is not a conflict of interest.