Investigation Of Physicochemical And Functional Properties Of Green Tea Powder Affected By Temperatures And Carrier Concentrations Using Spray - Drying Technique

Abstract

The present study aimed to investigate the effects of inlet air temperatures and the carrier concentration on the physicochemical and functional properties of green tea powder during the process of spray-drying. Two independent variables including inlet air temperatures (110°C, 130°C, 150°C) and mixtures of carrier agents (Gum Arabic and gelatin) were studied. The concentrations of mixture carrier agent added were 5%, 10%, 15% (w/v). The powder was obtained from the Lab Plant SD06 spray dryer. The results revealed that moisture content (MC), solubility, scavenging activity, total flavonoid content (TFC) and total catechin content (TCC) of samples varied in the range of 2.86 – 10.59%, 59.24 – 76.51%, 20.47 – 42.92%, 2.59 – 7.08 mg RE/g and 0.95 – 2.41 mg CE/g, respectively. Color values of tea powder (L, a and b) were 44.6 – 49.54, -17.83 to -12.47 and 19.57 – 31.39, respectively. The study on temperatures showed that all of the analyzed parameters were significantly affected by the shift in temperatures. However, the quality of the green tea powders was also influenced by different concentrations of carriers. From the results of this study, the powder produced by mixing with GA and gelatin at the concentration of 10% at 130°C retained the relatively low moisture content (5.87%); high levels of scavenging activity (41.60%), TFC (6.86 mg RE/mg) and TCC (2.24 mg CE/mg) with a high-water soluble ability (70.94%) as compared to the others, matching well with quality requirements for an instant powder product.