Tea or coffee is certainly a philosophical question. What is the first thing you drink when you arrive at work? In all cases, it's about getting the day off to a good start. But is too much caffeine good? Can't you do something with chitosan? We looked around and found what we were looking for in South Korea. A new type of tea bag that decaffeinates the tea in the cup itself. An alginate-chitosan hydrogel was used for this.