Determination of total color and brightness preference of tea among Ankara inhabitants and according to these data evaluation of the effects on human health by determining fluoride ion content of tea infusions prepared

Tea, whose homeland is Southeast Asia, has been a beverage consumed all over the world since the day it was discovered. Take into account that tea consumption in Türkiye is at all times of the day and every season of the year, the consumption frequency reaches quite high rate. For this reason, it has been the subject of many studies to evaluate the effects of the compounds it contains on human health, one of which is fluorine. Within the scope of this thesis, 43 granulated tea samples were collected from various retail department store chain in Ankara. Total fluorine contents of these teas were determined and then tea infusions were prepared with a ratio of 6/250 (g/ml) based on traditional brewing method. Total Color, % Brightness and Color Scales were analyzed from the fluoride ion content and optical densities at 460 nm of these infusions. In addition, tea infusions were supplied from 63 teahouse in Ankara, which were brewed with Türk traditional methods and served to customers in traditional tea glasses. And the fluoride ion content and Color Scale analyzes of these 63 tea infusions were analyzed. The total fluorine content of granulated tea samples, the average fluorine in Black Sea region tea was 183.93 mg/kg (Min: 135.87; Max: 327.86), the average fluorine in imported teas was 105.02 mg/kg (Min: 75.40; Max: 151.32), is detected. The variance value of this data was calculated as 2156.25. The fluoride content of tea infusions brewed from these granulated teas at a rate of 6/250 (g/ml) with the traditional method is 3.32 mg/L (Min: 2.15; Max: 4.40) in domestic tea, while the average fluoride content in imported tea is 2.06 mg/L ( Min: 1.46; Max: 3.08) was found. The variance of these data was calculated as 0.49, and it was also found that the fluoride in granulated tea was extractable at a rate of 52.94% to 93.79% (Average: 78.24). The variance of these values is 114.28, and it is concluded that they are distributed within a wide range, although not as much as the fluoride content of granulated tea. According to the Sperman correlation analysis results, a highly positive and significant (r = .753; p < .01) relationship was found between the fluoride content of the tea infusion and the fluorine content of the granulated tea, as expected. According to the results of simple linear regression analysis, the model was found to be significant (p<.001). The fluoride contained in granulated tea predicts the fluoride ion in tea infusions positively and significantly, as expected (β = .811, t (43) = .143, p < .001). %66,0'ini (R2adjusted= .658) of the fluoride ion contained in tea infusions associated with the fluoride in granulated tea. In addition, as a result of the Sperman correlation analysis, there was a small positive difference between the Color Scale and % Brightness data (r = .292; p < .01) and a large negative direction between the Total Color data (r = -.883; p < , 01) correlation was found. With this study, Color Scale is recommended as an accurate, effective and fast analysis method that can be used in brewed tea samples. As the scale increases, the darkness of the tea color decreases. According to the data of 63 tea infusions served for final consumption in Ankara, the average fluoride ion content of the samples obtained was determined as 2.61±0.57 mg/L (min=1.22; max=3.49) and the variance was 0.329. An average value of 8.97±0.44 (min=7.84; max=10.15) was obtained for the Color Scale. The variance of the Color Scale is 0.192. When the max, min and average fluoride ion concentrations obtained and the Adequate Intake (AI) and Hazard Quotient (HQ) depending on tea consumption from two glasses to 30 glasses (1 glass = 100 ml) are evaluated, women over 15 years of age and 15-24 years old living in Ankara are evaluated. It was concluded that consuming eight, 24 and 11 cups of tea, respectively, would be appropriate for AI for women over the age of 15 and men between the ages of 15-24 living in Ankara. For HQ>1 possible, in the same order; calculated as 10, 28 and 13 glasses. In order to reach adequate intake for men over the age of 24 living in Ankara, 11 cups of tea for maximum concentration and 15 cups of tea for average concentration should be consumed. However, at the minimum concentration, it is seen that sufficient intake cannot be reached even in the 30th glass. HQ>1 can be reached by consuming 13 glasses of tea at maximum concentration, more than 30 glasses for minimum concentration, and 18 glasses for average fluoride concentration.