FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Effect of storage on content of theaflavins and thearubigins in oolong teas


Theaflavins and thearubigins, which belong to a group of flavonoid pigments, have a strong impact on the gustatory properties and the colour of fermented teas. The objective of the research study was to determine the effect of packaging type as well as storage time and conditions on the content of theaflavins and thearubigins in oolong teas. The teas were stored for 12 months. The initial mean content of theaflavins was 0.30 g/100 g of oolong tea, and of thearubigins: 5.30 g/100 g of tea. After 3 months of storage, a statistically significant (p ≤ 0.05) decrease in the content of thearubigins occurred (to 4.04 g/100 g of tea on average) and after 4 months, the reported level of the decreased content of theaflavins was 0.20 g/100 g of tea on average. After 12 months of storage, the decreased level of theaflavins was 76.66 % and of thearubigins: 59.24 %. It was proved that the content of those substances fluctuated less in the case of the teas stored in original paper packaging (paper bag with an inner protective layer and a foil on its surface) and in packaging of metal boxes. The glass and paper packaging exposed to stray light were the least beneficial owing to the instability of flavonoid pigments. It was found that during storage of the teas, a degradation of pigments occurred, and the storage time and conditions determined the colour of the oolong tea.


oolong tea, theaflavins, thearubigins, colour, UV-VIS spectrophotometry