33G-25 |
|
N. PANDJAITAN and L. R. Howard. Dept. of Food Science, Univ. of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704 The increasing demand for natural b-carotene and lutein in the food and nutraceutical industries has resulted in efforts to identify alternative extraction methods, since conventional methods are expensive and use toxic organic solvents. Spinach is an excellent source of b-carotene and lutein, which have numerous purported health benefits. Although supercritical carbon dioxide extraction (SCCO2) has been used to efficiently extract carotenoids from plants and foods, optimal SCCO2 parameters for extracting carotenoids from spinach are unknown. The objectives of this research were to maximize SCCO2 extraction efficiency of b-carotene and lutein from spinach by optimizing three factors: temperature, pressure and ethanol as a polar modifier. SCCO2extraction of carotenoids from freeze dried spinach was conducted using three levels of pressure (30, 40 and 50MPa), temperature (40, 55 and 70 oC) and ethanol concentration (0, 7.5 and 15%). b-carotene and lutein contents of the extracts were determined by HPLC. Response surface models were used to determine optimum conditions. Insignificant terms were excluded from the final models. Ethanol concentration and pressure were found to be the two most important factors influencing extraction of lutein (R2=0.90), with maximum extraction efficiency obtained at the highest level of ethanol and pressure. A second-order response surface in terms of ethanol concentration, pressure and temperature were used to predict extraction of b-carotene. The final model included all linear, quadratic and linear by linear interaction terms (in terms of each of the three factors) except the quadratic effect of temperature and the temperature by pressure interaction (R2=0.99), with maximum extraction efficiency obtained at the highest level of each factor. Our results demonstrate that high efficiency extraction of lutein and b-carotene from spinach is feasible by SCCO2 using ethanol as a modifier.
Session 33G, Nutraceuticals & Functional Foods: Lipid and probiotic functional foods
|