Распад нелетучих веществOne sensory indicator of coffee’s flavour degradation due to storage is an increase in its harsh, sour, and bitter qualities. Ted Lingle attributes this flavour change to the breakdown of chlorogenic acids in the brew as it is stored. Chlorogenic acids (CGAs) are the most abundant type of acid found in brewed coffee. Lingle tells us the content of CGAs in the finished brew reach as high as 15% of the total dissolved solids (The Coffee Brewing Handbook, 1985).
Молекулярная структура хлорогеновой кислоты и ее составных частей, хинной и кофейной кислот (Сантос и др., 2006)