Total Polyphenols Content Antioxidant Activity

27 temperature 180˚C. the sample cannot dry properly and it stuck in the wall and result the higher of moisture content.

2.2 Total Polyphenols Content

The Folin-Ciocalteu assay is one ofthe oldest methods developed to determine the content of total poliphenols. The total polyphenols of green tea powder variated from 27.27-30.69 ww db. The highest total polyphenols content was found in tea powder with treatment 6 solid concentration in feed and inlet air temperature 180˚C about 30.69 ± 0.17 ww db and the lowest polyphenol content was found in tea powder with treatment 3 solid concentration in feed and inlet air temperature 220˚C about 27.27 ± 0.04 ww db. An increase inlet temperature 180- 220˚C decrease polyphenols content and increase feed concentration not affects and results variated amount of total polyphenols. Another research reported a slight decrease in total polyphenols content of the spray dried soybean extract by increasing the inlet air temperature Georgetti et al., 2008.

2.3 Antioxidant Activity

Antioxidant activity DPPH free radical scavenging activity was determined with DPPH scavenging activity. The DPPH 2,2-diphenyl-1picrylhydrazyl system offers a stable radical- generating procedure. It is sensitive enough to detect active principles at low concentrations. Antioxidant activity of green tea powder variated from 218.80 - 247.77 mmol Trolox100 g db. The highest antioxidant activity was found in tea powder with treatment 6 solid concentration in feed and inlet air temperature 180˚C about 247.77 ± 5.65 mmol Trolox100 g db and the lowest polyphenol content was found in tea powder with treatment 3 solid concentration in feed and inlet air temperature 220˚C about 218.80 ± 0.98 mmol Trolox100 g db. An increase inlet temperature 180- 220˚C decrease antioxidant activity slightly, but an increase feed concentration , it will increase antioxidant activity. Based on the results, the highest antioxidant activities of green tea powder 247.77 ± 5.65 mmol Trolox100 g db due to the high content of total polyphenols compounds 30.69 ± 0.17 ww db as well as. It similar with another research that reported the total antioxidant activity of the samples can be substantially associated with the phenolic substances present in the mountain tea spray dried. There was a significant positive correlation P 0.0001 and r 2 0.98239 between the results of the Total polyphenols and antioxidant activity of the samples Nadeem et al, 2011.

2.4 Catechins and Caffeine g100g db Content of Green Tea Powder