4.1 Key findings
Organic peppermint tea required an average of 15.33 drops and therefore it has the least caffeine. In an ascending order of caffeine content after organic peppermint tea, japan green tea with matcha required an average of 9.33 drops, ceylon tea required an average of 9.00 drops, lavender tea required an average of 4.33 drops, raspberry tea required an average of 4.00 drops, kiwi & strawberry tea required an average of 3.33 drops, peach and passionfruit tea required an average of 3.33 drops, blackcurrant tea and jasmine tea required an average of 3.00 drops, gunpowder tea required an average of 2.67 drops, lemon tea required an average of 1.33 drops, black tea required an average of 1.00 drop and therefore has the most caffeine.
4.2 Explanation of key findings
Tannic acid is a polymer of gallic acid molecule and glucose. Tannic acid will hydrolyze into glucose and gallic, or ellagic acid units that is odorless but has a very astringent taste. Tannic acid is also a commercial form of tannin that is not a true acid but is an acid like substance called polyphenol. Caffeine is the name of 1, 3, 7 caffeine and a water soluble alkaloid. Both tannic acid and caffeine are phytochemicals. Traditionally, many people have thought of teas' caffeine levels as being associated with tea "types," such as black tea, green tea and white tea. More recently, scientific testing has shown that variations in caffeine levels of different tea types have more to do with how they are brewed than how they were processed into tea.
4.3 Evaluation of hypothesis
Our hypothesis was “If I use blackcurrant tea, then the least caffeine will be present as compared to the other drinks.” Our hypothesis was proven wrong as based on our experiment. Organic peppermint tea had the least amount of caffeine, not blackcurrant tea. When we tested organic peppermint tea, we got an average of 15.33 drops of tannic acid solution before a white precipitate formed, however when we tested blackcurrant tea, we got an average of 3 drops of tannic acid solution. Thus organic peppermint tea had the least amount of caffeine, not blackcurrant tea.
4.4 Areas for improvementWhen we were adding tannic acid into the different teas, we used a plastic dropper and counted the number of drops it take, for a more accurate result, we can use a micropipette to measure the actual amount of tannic acid needed.