TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Process: In the process above, step (a) is catalyzed by a lipase. The triglyceride feedstock is a vegetable oil. The alcohol having 1 to 6 carbon atoms (C1-C6) is selected from methanol; ethanol; propanol; butanol; isobutanol; pentanol; pentanediol; isopentanol; hexanol; and their combination. At least 50% of the alcohol having 1 to 6 carbon atoms (C1-C6) is obtained from unreacted alcohol isolated from the alcoholysis reaction mixture, and/or from generated alcohol isolated from the condensation reaction mixture, and recycled to step (a). The fraction comprises unsaturated C18 fatty acid alkyl esters is further enriched in unsaturated C18 fatty acid alkyl esters by removal of saturated C18 fatty acid alkyl esters. The fraction comprises unsaturated C18 fatty acid alkyl esters is further enriched in specific unsaturated C18 fatty acid alkyl esters selected from C18:1 (mono-unsaturated) fatty acid alkyl esters; C18:2 (di-unsaturated) fatty acid alkyl esters; C18:3 (tri-unsaturated) fatty acid alkyl esters; and their combination. At least one further fraction is separated from the reaction mixture, where the at least one further fraction is selected from alcohol; glycerol; and C16 fatty acid alkyl esters. The separation of fractions is conducted with a method selected from distillation, crystallization, centrifugation, urea precipitation, membrane filtration; molecular sieve; and their combination. The lipase used in step (a) and (c) is selected from Aspergillus lipase; Aspergillus niger lipase; Thermomyces lanuginose lipase; Candida antarctica lipase A; Candida antarctica lipase B; Candida cylindracae lipase; Candida deformans lipase; Candida lipolytica lipase; Candida parapsilosis lipase; Candida rugosa lipase; Corynebacterium acnes lipase; Cryptococcus spp. S-2 lipase; Fusarium culmorum lipase; Fusarium heterosporum lipase; Fusarium oxysporum lipase; Mucor javanicus lipase; Rhizomucor miehei lipase; Rhizomucor delemar lipase; Burkholderia cepacia lipase; Pseudomonas camembertii lipase; Pseudomonas fluorescens lipase; Rhizopus lipase; Rhizopus arrhizus lipase; Staphylococcus aureus lipase; Geotrichium candidum lipase; Hyphozyma sp. lipase; Klebsiella oxytoca lipase; and their wild-type orthologs and homologs; and their variants that have an amino acid sequence that is at least 60-99% identical to any of those wild-type enzymes. The lipase is immobilized. The amount of C18:1 (mono-unsaturated) fatty acid residues is higher than the amount of C18:p (poly-unsaturated) fatty acid residues in the triglyceride product. A fraction of saturated fatty acid alkyl esters are separated from the reaction mixture. EXAMPLE - No suitable example given.