Red yeast -carotene content: developing extraction and determination for improving poultry nutrition

Vitamin A is an essential nutrient, for both production and reproduction of farm animals, however, most animals are unable to synthesize de novo precursors of vitamin A (fl-carotene), and dietary supplementation is mandatory. The current paper aims to evaluate the analytical parameters and to improve the method efficiency for determining fl carotene content in red yeast and the internal laboratory validation protocol. Our method stands for the ultraviolet visible spectrophotometric uses, having the Lambert-Beer law as the basis. To determine the fl-carotene content, dimethyl-sulfoxide was employed as a solvent, calibration curve, and visible spectra were evaluated (300-900 nm). The linearity of beta carotene measured at 465 nm using the UV-Vis method linearity range was 6.1-36.6 mu g/ml, R2=0.997, LOD = 5.39 mu g/ml, LOQ = 16.32 mu g/ml, SD less than 5% and RSD in between 1-15%. In conclusion, the fl-carotene spectroscopic method determination is a cheap, and efficient method, suitable for fl-carotene determination and retinol and retinoic acid estimation for nonconventional feed additives such as yeasts.