| 摘要 |
A method of increasing a fraction of free carotenoids in a source of carotenoids in which at least some of the carotenoids are fatty acid esterified carotenoids is disclosed. The method is effected by contacting th e source of carotenoids with an effective amount of an esterase under conditio ns effective in deesterifying the fatty acid esterified carotenoids, thereby increasing the fraction of free carotenoids in the source of carotenoids. In specific embodiments, the enzymatic reaction is carried out in the presence of cellulose degrading enzymes, or protein degrading enzymes, or protein degrading enzymes, or emulsifiers, or metal ions. The esterase can be in immobilized forms. The deesterification product mixture can be extracted wit h ethyl acetate under alkakine conditions and/or subjected to a chosmatographi c extraction in order to reduce the Vitamin E content. Method for determining the esterase efficiency in the carotenoid ester transformation are disclosed together with methods of screening for suitable esterases and methods of determining the optimal reaction conditions. In one embodiment, the composition of enzymatically deesterified red carotenoids comprises at least about 40 percent by weight capsanthin, at least 15 percent by weight zeaxanthin and capsolutein, at least about 2 percent by weight violaxanthin, at least about 1 percent by weight capsorubin, at least about 5 percent by weight beta cryptoxanthin, at least about 3 percent by weight beta carotene, and eventually about 1 percent of vitamin E. Said composition of matter has antioxidant activity. The application also relates to a method of extracting red pepper oleoresin, the method comprising: homogenizing red-pepper fruits in water into a juice; centrifuging the juice so as to obtain a pellet; mixing the pellet with ethanol and ethyl acetate; homogenizing the pellet with the ethanol and the ethyl acetate; removing dry materials; and evaporating solvents so as to obtain red pepper oleoresin. |
