Changes on catechin contents and antioxidant capacities of Bengakhan tea during production | เธเธฒเธฃเนเธเธฅเธตเนเธขเธเนเธเธฅเธเธเธฃเธดเธกเธฒเธเธชเธฒเธฃเธเธฃเธฐเธเธญเธเธเธฒเธเธดเธเธดเธเนเธฅเธฐเธเธงเธฒเธกเธชเธฒเธกเธฒเธฃเธเนเธเธเธฒเธฃเธเนเธฒเธเธญเธญเธเธเธดเนเธเธเธฑเธเธเธญเธเธเธฒเนเธเนเธเธเธเธฑเธเธเนเนเธเธฃเธฐเธซเธงเนเธฒเธเธเธฃเธฐเธเธงเธเธเธฒเธฃเธเธฅเธดเธ
2007
Varipat Areekul(King Mongkut's Institute of Technology Ladkrabang, Bangkok (Thailand). Faculty of Agricultural Industry) E-mail:[email protected] | Naraporn Phomkaivon(King Mongkut's Institute of Technology Ladkrabang, Bangkok (Thailand). Faculty of Agricultural Industry)
Changes of total catechin content and antioxidant capacity were examined as a consequence of processing steps from raw material to final tea product of Benjakhan (Gynostemma pentaphyllum (Thunb.ex Murray) Makino]. Total catechin content was evaluated by HPLC method while the antioxidant capacities were evaluated by ferric reducing antioxidant capacity (FRAP), Folin Ciocalteu reagent (FCR) and DPPH scavenging assay. The fermentation and drying steps statistically affected on the decrease in total catechin contents and antioxidant capacities whereas roasting stage significantly increased all antioxidant capacities (p LT 0.05). The total catechin contents and antioxidant capacities decreased as an increase in fermentation duration from 0 to 190 min. Drying temperatures varied from 50-80 deg C at air velocities from 0-0.6 m/s influenced the changes in total catechin contents and antioxidant capacities. The results indicated that the processing steps, in general, affected the changes on total catechin contents and antioxidant capacities of the tea.
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