Decrease in the Antioxidant Capacity in Beverages Containing Tea Extracts during Storage

Abstract

The aim of this work was to determine antioxidant capacity of beverages containing black, white, and green tea extracts using the photochemiluminescence method, and to monitor its changes based on the storage temperature and time. Samples were stored at two different temperatures (refrigerated at 4°C and laboratory temperature 22°C), analyzed after opening of the original package, and consequently after 4 and 7 days. Results of the antioxidant capacity are expressed as the standard equivalents, that is, ascorbic acid in mmol/L. The highest mean value of the antioxidant capacity was found after opening of the original package in fruit-juice-enriched samples and totaled 9.793 mmol/L. This group revealed significant dependence (P < 0.05) not only on the storage time, but also temperature. In samples without added fruit juices containing preservatives the value was 0.428 mmol/L. This group showed significant dependence (P < 0.05) on the decrease of antioxidant capacity only when based on the storage time. Samples without fruit juices or preservatives showed significant decrease in the antioxidant capacity (P < 0.05) after 4 days of storage based on the storage time. The dependence on temperature was revealed only after 7 days of storage.

Changes in phenolics and antioxidant capacity during short storage of ready-to-drink green tea (Camellia sinensis) beverage at commercial conditions

“…On the other hand, Kopjar et al (2009) reported a loss of the 10.38% in the total phenols content and the 4.07% in the DPPH antioxidant capacity after one week of storage at room temperature in water-soluble green tea extract. Although Nekvapil et al (2012) used another method, they obtained findings similar to ours in the loss of the antioxidant capacity. They observed a decrease of 16% and 24% in the antioxidant capacity at four and seven days of storage at 22 °C, respectively, in a commercial green tea with aloe vera.…”

Antioxidant Capacity of Tea

“…Storage stability of green tea infusions depending on packaging material used (glass, PET, and retortable pouch) was evaluated by Kim et al (2011b). It was reported that cold storage at 4°C of tea beverages in PET bottles ensures a slower decrease in catechin content in white, black, and green teas (Nekvapil et al, 2012). The antioxidant capacity of green tea infusions decreased by 18, 14, and 30% in glass, PET, and retortable pouch, respectively, during the 12 weeks of storage.…”

Stability of total phenolic and antioxidant capacity in ready-to-drink black and green tea formulations

“…The percentage reductions are close to those observed for the antioxidant capacity (14 and 22%) measured by the ABTS method, which suggests that the reductions in TPC were accompanied by the same proportions of loss in the capture of the free radical ABTS displayed by ready-to-drink teas. Development, v. 9, n. 10, e219108160, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i10.8160 11 No different behavior was observed on AC decay among formulations of teas added of fruit juices and the natural tea, contrary to the study of Nekvapil et al (2012) where the addition of fruit juices as lemon and peach implied in a positive impact on the antioxidant capacity of beverages containing white, black and green tea extracts.…”

“…The authors suggest that differences were caused by different oxygen and light permeability of packaging materials. Nekvapil et al (2012) reported that cold storage at 4 °C of tea beverages in PET bottles ensures a slower decrease in antioxidant capacity in white, black, and green teas, compared to mild temperatures (22 °C).…”