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Polyphenolic Content and Antioxidant Capacity of White, Green, Black, and Herbal Teas: a Kinetic Study
Shannon, Emer; Jaiswal, Amit Kumar; Abu-Ghannam, Nissreen
Camellia sinensis teas, and tisanes derived from herbs or fruit, are rich in polyphenolic, antioxidant compounds. This study compared the total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), DPPH radical scavenging capacity, and caffeine content of teas (black, green, white, chamomile, and mixed berry/hibiscus) over a range of infusion times (0.5–10 mins) at 90°C. Green, followed by black tea, respectively, had the greatest TPC (557.58 and 499.19µg GAE/g), TFC (367.84 and 325.18µg QE/g), FRAP (887.38 and 209.38µg TE/g), and DPPH radical scavenging capacity (1233.03 and 866.39µg AAE/g). Caffeine content per cup (200mL) in black, green, and white tea was 63, 51, and 49mg respectively. Changes in the phenolic content and antioxidant capacity of teas were modelled using zero, first, and fractional-conversion-first-order (FCFO) kinetic models. Results fitted a FCFO kinetic model, providing useful data for maximum phytochemical preservation in the optimisation of industrial and domestic processing. As a dietary comparison, green, black, and white tea were found to have a greater phenolic content and antioxidant capacity than fresh orange and apple juice. It can be concluded that green and black teas are significant sources of dietary phenolic antioxidants.
Keyword(s): Camellia sinensis; White tea; Herbal tea; Phenolic compounds; Antioxidants; Kinetic modelling; Comparative Nutrition; Food Chemistry; Plant Sciences
Publication Date:
2017
Type: Journal article
Peer-Reviewed: Unknown
Institution: Dublin Institute of Technology
Citation(s): Articles
Publisher(s): Dublin Institute of Technology
File Format(s): application/pdf
First Indexed: 2017-12-14 06:56:24 Last Updated: 2017-12-14 06:56:24