Enzymatic modification of sterols using sterol-specific lipase

Process for the in situ enrichment of a fat-based product with esterified phytosterol ester(s), comprising the steps of:

• (a) adding at least one phytosterol to a fat-based product;
• (b) adding to the mixture of (a) an immobilized-surfactant coated lipase complex possessing a high level of sterol-specific, selective alcoholytic activity and minimal acidolytic and interesterfication activities;
• (c) incubating the reaction mixture, for a time sufficient for maximal alcoholysis of said free sterol to occur;
• (d) optionally removing the immobilized lipase complex upon completion of the reaction;
• and
• (e) optionally removing the esterified cholesterol obtained in (d).

(New) Process for the in situ enrichment of a fat-based product with esterified phytosterol esters(s), comprising the steps of:

• (a) adding at least one phytosterol to a fat-based product;
• (b) adding to the mixture of (a) at least one carboxylic fatty acid or ester derivative thereof;
• (c) adding to the mixture of (b) an immobilized-surfactant coated lipase complex possessing a high level of sterol-specific esterification activity and minimal acidolytic and interesterification activities, said complex optionally being surfactant-coated;
• (d) incubating the reaction mixture, for a time sufficient for maximal esterification of said free sterol to occur;
• (e) optionally removing the immobilized lipase complex upon completion of the reaction;
• and
• (f) optionally removing the esterified cholesterol obtained in (d).