Abstract:

Objective: This work aimed to optimize the conditions for the degradation of astaxanthin by a purified carotenoid
cleavage enzyme from Staphylococcus pasteuri. Methods: The degradation products were measured by HPLC. Orthogonal
arrays design combined with quadratic polynomial stepwise regression analysis was applied to optimize the conditions for
astaxanthin degradation. Results: The HPLC analysis showed that this carotenoid cleavage enzyme had the ability to degrade
astaxanthin. pH, time, temperature and their interactions had significant effects on the contents of degradation products
(P < 0.01). The interaction between pH and time showed the most significant contribution to the contents of degradation
products under the optimized conditions with a value of direct path coefficient of 12.726 9. The optimal reaction conditions
were determined as follows: pH 4.5, and incubation at 50 ℃ for 7 min. Under these conditions, the total yield of degradation
products was 1.75 times higher than the defined apocarotenoids yield. Conclusion: This carotenoid cleavage enzyme has a
high ability to cleave astaxanthin. The optimal conditions for maximum yield of products have been obtained.

Key words: a carotenoid cleavage enzyme, astaxanthin, yield of apocarotenoids, quadratic polynomial stepwise regression analysis