Annatto seeds: Extraction of essential oil of four cultivars, characterization by LC-MS/MS and non-destructive NIR Spectrometer

In annatto seeds, we find a healthy and nutritious pigment in the diet. Annatto seeds are grown in South and Central America and have been used for centuries as a natural food coloring. The Bixin pigment can be extracted after extracting the essential oil, adding more value to the seed. Essential oil also has great value in the industry. The identification of four cultivars of annatto seeds in the trade is important, and quick evaluation whit preserving the seeds as near-infrared techniques can be a good alternative. The current work investigated near-infrared spectroscopy (NIRS) for annatto seeds and essential oil. The essential oil was extracted with the Clevenger apparatus and analyzed by gas chromatography coupled with mass spectroscopy. NIR spectra were obtained from fresh seeds and after the essential oil extraction. The best pre-treatment was the second derivative for fresh seeds, and after oil extraction both the first and second derivatives are adequate. NIR spectroscopy showed the potential for discrimination of annatto seeds cultivars non-destructively.