Effect of infusion time on black tea quality, mineral content and sensory properties prepared using traditional Turkish infusion method

Abstract

Tea is not only just a beverage in Turkey, it is but also a considerable part of the Turkish culture. With this study, it is aimed to reveal the best infusion time in the traditional Turkish type infusion method by evaluating the quality parameters, mineral content and sensory parameters of infusion depending on the increasing infusion time. Transition rate of the quality parameters to the infusion were between 69.8% and 90.2% on average, theaflavin (TF) was the highest on the other hand, the total polyphenols were the lowest. Transition rate of minerals was not higher as much as quality parameters and varied between 25.1% and 41.8% on average. The highest one was Zinc (Zn) and the lowest one was Calcium (Ca). All quality parameters and minerals except caffeine, TF and Cu showed a correlation with the infusion time. Extract, TP, TR, TC, turbidity, Zn, Ca and Mn were positively correlated, on the other hand brightness, L, a*, b* and Al showed negative correlation relationship. In terms of sensory evaluation, colour and bitterness showed positive correlation with increasing infusion time, while brightness, clarity, astringency, aroma and overall evaluation showed negative correlation. When the quality parameters, minerals and sensory parameters of the infusions are evaluated, it has been seen that the ideal infusion time is 15 min according to the traditional Turkish type black tea infusion method and infusion time should not exceed 30 min.