Chlorophyll as an indicator of green tea quality

Abstract

The objective of this work was to study the changes in chlorophyll contents in green teas stored under different conditions and to suggest the most suitable way and length of green tea storage. A secondary aim was to evaluate the possibility of using the chlorophyll content as an indicator of tea freshness. Samples for analysis were obtained from a range of tea-growing regions. Chlorophyll contents were measured using UV-vis spectrophotometry. Chlorophyll absorbance was measured at 642.5 and 660 nm. Prior to storage, chlorophyll concentration in teas ranged from 1.12 to 1.89 mg per 1 g of tea, which corresponded to data given by other authors. Storage was found to lead to a decline in chlorophyll concentration. From the 6 th month of storage onwards, a significant decrease (P < 0.05) was observed in all samples, irrespective of storage conditions. Based on the findings of this study, original and metal packaging can be considered the most chlorophyll-friendly. On the other hand, glass and paper packaging stored in direct daylight were found to have the strongest impact on chlorophyll concentration. Overall, it can be concluded that the storage time can have a strong influence on oolong green tea colour as an important qualitative variable. Thus, the shelf-life of tea should be shorter than the 12 months claimed by most manufacturers. Once the relationship between changes in chlorophyll concentration and length of the storage period had been established, the chlorophyll content was suggested as an indicator of the storage time (freshness) of a tea substance.

Synergisms in alpha-glucosidase inhibition and antioxidant activity of Camellia sinensis L. Kuntze and Eugenia uniflora L. Ethanolic Extracts

“…The total content of chlorophylls was proposed as quality parameter for C. sinensis and the concentration found among 14 samples ranged from 1.18 ± 0.16 to 1.98 ± 0.11 mg/g of sample. [ 48 ] Thus, the value found in the present study was in agreement with the reported value. No report was found about the chlorophyll content in E. uniflora as far as we known.…”

Effects of gardenia seed, green tea, and cactus pear in rice batter on the chemical quality of lotus root bugak and frying oil

“…Pigment and antioxidant contents of food materials No pigment was detected in lotus root, but powdered gardenia seed, green tea, and cactus pear contained chlorophylls and/or carotenoids. Chlorophylls a and b were detected only in green tea powder at 59.46±0.77 and 151.91±7.26 mg/kg, respectively, which were lower than the reported values (11). A wide range of the chlorophyll contents in green tea depending on the cultivating area and processing method has been previously reported (12,13).…”

(−)-Epigallocatechin Gallate Stability in Ready-To-Drink (RTD) Green Tea Infusions in TiO2 and Oleic-Acid-Modified TiO2 Polylactic Acid Film Packaging Stored under Fluorescent Light during Refrigerated Storage at 4 °C

“…The a-value of the color change results agreed with previous research findings that green tea color becomes more reddish as a result of the oxidation of polyphenolic compounds. Chlorophyll is a green pigment in green tea, and its amount decides the final color of green tea infusion [ 23 ]. Light may degrade chlorophyll in RTD green tea infusions during storage because light absorptions of the photosensitizer chlorophyll are at the wavelength of 430 and 660 nm [ 12 , 23 ].…”

“…Chlorophyll is a green pigment in green tea, and its amount decides the final color of green tea infusion [ 23 ]. Light may degrade chlorophyll in RTD green tea infusions during storage because light absorptions of the photosensitizer chlorophyll are at the wavelength of 430 and 660 nm [ 12 , 23 ]. Hence, the light may reduce the green color of RTD green tea infusions in the packaging during storage.…”