NOVELTY - Production of esters of ricinoleic acid from a vegetable oil comprises: (a) an enzymatic transesterification reaction performed in the presence of an alcohol and lipase to form a mixture (M) comprising mono-, di- and triglycerides of ricinoleic acid, esters of fatty acid other than ricinoleic acid, and alcohol; (b) separation of the mixture into at least two fractions comprising fraction A rich in glycerides of ricinoleic acid and fraction B rich in esters of fatty acid other than ricinoleic acid; (c) transformation of the ricinoleic acid glyceride into ester of ricinoleic acid.    USE - The fraction enriched with ricinoleic acid ester is useful for obtaining 11-amino undecanoic acid and the fraction enriched with esters of fatty acid other than ricinoleic acid is useful for obtaining biodiesel (all claimed). The 11-amino undecanoic acid is useful for the synthesis of Rilsan 11 (RTM: Polyamide).    ADVANTAGE - The process allows the bioselective extraction of ricinoleic acid ester at high yield.    DETAILED DESCRIPTION - Production of esters of ricinoleic acid from a vegetable oil containing ricinoleic acid, preferably castor oil, comprises: (a) a first enzymatic transesterification reaction performed in the presence of a lightweight alcohol and lipase extracted from Geotrichum candidum to form a mixture (M) comprising mono-, di- and triglycerides of ricinoleic acid, esters of fatty acid other than ricinoleic acid, and alcohol; (b) separation of the mixture (M) into at least two fractions comprising fraction A enriched with glycerides of ricinoleic acid and fraction B rich in esters of fatty acid other than ricinoleic acid; (c) transformation of the ricinoleic acid glyceride content in fraction A into ester of ricinoleic acid to form fraction C enriched with esters of ricinoleic acid and a fraction rich in alcohols. An INDEPENDENT CLAIM is included for the fraction enriched with ester of ricinoleic acid obtained by the process, where the raw material is: a pure castor oil, and the fraction contains at least 94 wt.%, preferably 95-98 wt.% of ricinoleic acid methyl ester; or an oil poor in ricinoleic acid, and the fraction contains at least 75 wt.%, preferably 82-91 wt.% of ricinoleic acid methyl ester.