Investigation on Natural Color Extraction from Black Tea Waste

Tea is a source of natural color. Extraction of colored as a byproduct will make tea more remunerative. This study suggested the optimal conditions for natural color extraction from black tea waste. Tea manufacture waste was used in different concentration of solvent ethanol: water (۵۰:۵۰, ۳۰:۷۰, ۱۰:۹۰, and ۰:۱۰۰), time (۳۰, ۶۰, and ۹۰ min) and temperature (۲۰, ۵۰, and ۸۰°C). Factorial experiment with three factors (solvent, time and temperature) was performed in a completely randomized design with three replications. Extracted color was used in jelly compared to commercial color. According to the results, the total color extracted from ۵۰:۵۰ ethanol: water at ۸۰°C was more than the other conditions (p ≤۰.۰۱). In ۸۰°C, time has no significant effect on color extraction in different solvent ratios. Extracted color had antioxidant activity in compared to commercial color. The taste of jelly colored by extracted color was no significant difference in compared with the jelly colored by commercial color (p≤۰.۰۵). Although the difference in outward appearance was easily detected by panelists, they preferred tea extracted color jelly in compared to commercial colored.

Keywords:

Black tea waste , Color extraction , Jelly , Sensory evaluation