High yielding and direct enzymatic lipophilization of ferulic acid using lipase from Rhizomucor miehei

•Ferulic acid was efficiently esterified with primary alcohols by R. miehei lipase.•Yields were 76% and 88% for ethyl ferulate and decyl ferulate at optimized conditions.•The syntheses of C3, C4, C6, C8, C14 and C18 ferulate esters were also successful.•Short alcohols were preferentially esterified with ferulic acid by R. miehei lipase.

Ferulic acid is an abundant phenolic acid and a good antioxidant that occurs naturally in free form or esterified. The structure of this hydroxycinnamic acid, with a hydroxyl group in para-position, makes enzymatic esterification with lipases challenging. Adjusted lipophilicity of the ferulic acid as an antioxidant is crucial for complex food matrices, calling for a simple esterification method. Esterification of ferulic acid with ethanol and decanol in n-hexane using immobilized lipase from Rhizomucor miehei was optimized using surface response methodology. After 72 h, the yields were 76% and 88% for ethyl ferulate and decyl ferulate, respectively. Furthermore, ferulate esters of primary alcohols with varying chain lengths from C-2 to C-18 were also synthesized, with yields ranging from 76% to 92%. Finally, ferulic acid was preferably esterified to short chain alcohols in a mixture of primary alcohols. This study provides simple and efficient methods for the enzymatic esterification of ferulic acid.

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