EFFECT OF ENZYMATIC TREATMENT OF CORN GLUTEN MEAL ON LUTEIN, ZEAXANTHIN AND β‐CRYTOXANTHIN EXTRACTION

ABSTRACT Response surface methodology was used to optimize some operating parameters on the effects of alcalase treatment extraction of lutein, zeaxanthin and β ‐cryptoxanthin from corn gluten meal (CGM) on the yield of total xanthophylls. Three independent variables tested were enzyme concentration, substrate concentration and hydrolyzing time. The t ‐test and P value indicated that the quadratic of the three variables, enzyme concentration and hydrolyzing time were important linear variables affecting the total xanthophyll yield ( P < 0.005), followed by substrate concentration ( P < 0.01). The interaction effect between enzyme concentration and hydrolyzing time was also significant ( P < 0.005). Considering the efficiency, the economy of materials and the feasibility of experiment, the technique parameters were optimized by constrained complex method. The optimum conditions were obtained as follows: the enzyme concentration, the substrate concentration and the hydrolyzing time were 4,367 U/g, 11.3% and 2.4 h, respectively. The highest total xanthophyll yield was predicted of 65.69 µ g/g when CGM was hydrolyzed under the optimum condition. The suitability of the model equation for predicting the optimal response values was tested using the selected optimum conditions; the experimental yield was 65.06 ± 0.78 µ g/g, which was found to be in agreement with the predicted yield. PRACTICAL APPLICATIONS Corn gluten meal (CGM), a major by‐product of corn wet milling, contains (on a dry basis) 200–400 µ g/g carotenoids. There are ∼840,000 tons of CGM produced in China every year. If a part of CGM produced was manufactured further to produce carotenoids as foods, materials of foods and additives of pharmaceutical products, its value and presence in the marketplace would be increased.