Extraction of natural blue dyes from clitoria ternatea

Natural colorants can be alternative to synthetic colorants where they do not pose health hazards. However the production of colorants from natural sources are more difficult to handle and less stable. The usage of Clitoria ternatea flowers as natural sources of colouring materials in food industries is also still uncommon. So, this study was conducted to investigate the effect of different drying methods, size reductions, temperatures, solvents, static versus stirring conditions, concentrations (amount of flowers) and pH on the extraction of natural blue dyes from Clitoria ternatea. Fresh flowers were selected and undergone different drying processes namely sun, oven and vacuum drying at 50 °C. Those sample alsdliad been reduced their sizes by whole flower, cutting, grinding and pounding. The faster in drying rate was using vacuum oven at 50 °C by grinding the sample. Then, 95% ethanol and water were used as solvents in extraction process using water bath and by applied with the different temperature at (25, 50, 75) °C. It was shown that higher temperature gave the best extraction for water which is at (50 and 75) °C. The same results show water has the higher dyes absorbance during extraction in static and stirring conditions compared to 95% ethanol. The λmax of water was at 600nm while for 95% ethanol was at 400nm. For concentration of flower amounts (5, 10, 15, 20 and 30) g show the absorbance increase with the increasing concentration against time. The pH extraction was stable in medium condition which is at pH 6.7 with the values L*(45.53±2.87ab), a*(4.80±0.03b) and b*(0.05±0.97c) because it displays the blue colours. Analytical studies such as colour and UV-Visible spectrophotometer analysis were performed on the extract. The findings show that all parameters displayed significant effects on the extraction of natural blue dyes from Clitoria ternatea.