Using commercial lipases from various microbial origins, medium‐chain glycerides, such as mono‐, di‐, and tricaprin, were synthesized in isooctane from glycerol and capric acid. The enzyme reaction was performed with 0.35 M capric acid, 0.025 M glycerol, and 0.46 g silica gel to remove water in 5 mL of isooctane with 30 mg lyophilized lipase. Of the 21 kinds of lipases, 11 showed good synthetic activities. Lipases fromPseudomonas aeruginosa (Lipase PS),Rhizomucor miehei lipase andChromobacterium viscosum lipase (Lipase CV) showed high activities for the production of tricaprin, while lipase OF‐360 (fromCandida rugosa) and lipase D (Rhizopus delemar) were good for dicaprin production. Lipases CC and MY fromC. rugosa (C. cylindracea) and lipase D (Rhizopus delemar) were good for dicaprin production. Lipases CC and MY fromC. rugosa (C. cylindracea) also showed high activities for dicaprin and tricaprin. Some lipases, especially lipase PS, had high thermal stability over 60°C. The optimal lyophilization pH to dehydrate the lipase coincides with the optimal buffer solution pH for hydrolysis.

To investigate the synthetic patterns of triglyceride (triacylglycerol) by lipases in organic solvent, esterification patterns of triglyceride, diglyceride, and monoglyceride were monitored at various reaction times with 10 lipases. As a model study, tricaprin was synthesized from glycerol and capric acids (C 10:0 ) in isooctane. Lipases that were known to give nonspecific hydrolysis in aqueous solvent, such as lipase from Candida cylindracea, Lipase OF-360 (from C. rugosa), and Lipase MY (C. rugosa) showed nonspecific synthesis of tricaprin in organic solvent (Group I). There are two groups for esterifying triglycerides in organic solvent with 1,3-specific lipases: one consists of the lipases from Rhizomucor miehei, Pseudomonas aeruginosa (Lipase PS), and Chromobacterium viscosum (Lipase CV) (Group II), and another (Group III) is represented by Lipase AP (Aspergillus niger), Lipase FAP-15 (Rhizopus javanicus), and Lipase D (R. delemar). Although both groups showed 1,3-specific hydrolysis in aqueous solvent, Group III has stricter 1,3-specificity for the synthesis of tricaprin from dicaprin.

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