Natural colorants from cosmos sulphureus Cav. And Tagetes erecta L.: Extraction and characterization

Abstract

The objective of this research is to determine the optimum conditions in the extraction process of carotenoid from the flower Tagetes erecta L, which are found in Yogyakarta and to use these optimum conditions for the extraction and identification of carotenoid content in Tagetes erecta L. and Cosmos sulphurous Cav., that are found in the highlands and lowlands in the area of Yogyakarta. A laboratory-scale extraction was done in a three-neck flask with a heating mantle, which was equipped with cooler, mixer, and thermometer. The temperature of the extraction process in the entire study was fixed at 50°C to avoid the colorant degradation. The carotenoid content in the extract solutions was determined using gravimetric, chromatography, and spectrometry methods. Determination of the optimum conditions was done by varying the type of solvent, extraction time (10-120 minutes), dry solid mass to solvent volume ratio (0.05 - 1.0 g/mL), and agitation speed (600 - 900 rpm). The optimum conditions for the carotenoid extraction were used for extraction of the carotenoid content of Tagetes erecta L. and Cosmos sulphureus Cav., cultivated in lowlands and highlands in Yogyakarta. Using ethanol (96%) as a solvent resulted in a higher yield compared to the use of acetone. Optimization of the extraction process and evaluation of interaction effects of different operating variables (time, dry solid mass to solvent volume ratio, and agitation speed) was obtained using the Response Surface Method (RSM) of DOE Software Minitab. The optimum conditions for extraction of carotenoid compounds from Tagetes erecta L. were found to be 81 minutes, with a solid to solvent ratio of 0.05 g/mL, and agitation speed of 800 rpm. The yield of solute (g colorant in extract solution/g dry solid sample) of extraction under these optimum conditions was found to be 10.16%. Furthermore, it was found that the carotenoid content in Cosmos sulphureus Cav. was higher than that in Tagetes erecta L., and the plants from the lowlands have a higher carotenoid content than those from the highlands.