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Effect of batch extraction conditions on extraction of polyphenols from rooibos tea (Aspalathus linearis)
Author(s) -
JOUBERT E.
Publication year - 1990
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.1990.tb01090.x
Subject(s) - polyphenol , extraction (chemistry) , flavonoid , chemistry , phenols , chromatography , extraction ratio , food science , phenol , biochemistry , antioxidant , organic chemistry
Summary The effects of extraction temperature (23, 50, 60, 70, 80 and 90°C), mass ratio of extract: dry tea leaf (5:1 and 10:1) and flow rate of water (0.1 and 0.2m 3 /h) on extraction of total polyphenols, flavonoids and non‐flavonoid phenols from rooibos tea were determined with a single‐stage batch‐extraction system. Extraction of the different phenolic groups from tea leaves increased significantly with increasing temperature. The increase in total polyphenol extraction was due mainly to increasing extraction of flavonoids. Increasing mass ratio and decreasing flow rate resulted in better extraction of the different phenolic groups. The phenolic content of extract soluble solids also increased significantly with temperature. At extraction temperatures 23 and 50°C, increasing mass ratio resulted in a significant increase in total polyphenol and flavonoid content of the soluble solids. The non‐flavonoid phenol content increased significantly with increasing mass ratio at temperatures above 23°C. Flow rate did not significantly affect the total phenolic and flavonoid content of soluble solids.