Химия - Декофеинизирование - Триглицеридный метод
01 марта 2011Оглавление:
1. Декофеинизирование
2. Процесс Розелиуса
3. Прямой метод
4. Процесс CO2
5. Триглицеридный метод
6. Содержание кофеина в декофеинизированном кофе
7. Влияние декофеинизированного кофе на здоровье
Green coffee beans are soaked in a hot water/coffee solution to draw the caffeine to the surface of the beans. Next, the beans are transferred to another container and immersed in coffee oils that were obtained from spent coffee grounds.
After several hours of high temperatures, the triglycerides in the oils remove the caffeine—but not the flavor elements—from the beans. The beans are separated from the oils and dried. The caffeine is removed from the oils, which are reused to decaffeinate another batch of beans. This is a direct-contact method of decaffeination.
Декофеинизированный чай
Tea may also be decaffeinated, usually by using processes analogous to the Direct Method or the CO2 process, as described above. Fermentation does not affect the amount of caffeine in the tea, though tea-plant species may differ in natural caffeine content. Younger leaves and buds contain more caffeine per weight than older leaves and stems. Also, certain processes during production might lend a hand in either decreasing the caffeine content directly or simply lowering the rate at which it is released throughout each infusion. Several instances in China where this is evident is in many cooked pu’er teas, as well as more heavily fired Wuyi Mountain oolongs; commonly referred to as 'zhonghuo' or 'zuhuo'. A generally accepted statistic is that a cup of tea contains 40-50 mg of caffeine, roughly half the content of a cup of coffee. Although a common technique of discarding a short steep is believed to reduce caffeine content in a subsequent brew by 80-90 %, research suggests that a five-minute steep yields up to 70 % of the caffeine, and a second steep has one-third the caffeine of the first.
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