Improvement of bixin extraction yield and extraction quality from annatto seed by modification and combination of different extraction methods

Bixin from annatto seed was extracted by submerging the seeds in acetone and by combined extractions using sodium hydroxide and soybean oil in the dark to improve extraction yield and reduce content of volatile compounds in annatto extracts. The exclusion of light from acetone extraction did not significantly improve bixin extraction yield (68.5%) compared to the process carried out under daylight (67.3%), but it remarkably reduced contents of toluene and m-xylene in annatto extracts. Combined extraction using sodium hydroxide solution at 50 degrees C for 40 min and soybean oil at 100 degrees C for 20 min resulted in very low level of volatile compounds. Significantly higher extraction yield (53.7%) could be achieved by such a process as compared to a single extraction sodium hydroxide (31.8%) or soybean oil (42.9%) alone. In conclusion, the exclusion of light from acetone extraction and combined extraction significantly reduced concentration of undesirable volatile compounds. The combined extraction significantly improved bixin yield compared to the original extraction methods.