Production of structured lipids in a packed‐bed reactor with thermomyces lanuginosa lipase

Lipase‐catalyzed interesterification between fish oil and medium‐chain TAG has been investigated in a packedbed reactor with a commercially immobilized enzyme. The enzyme, a Thermomyces lanuginosa lipase immobilized on silica by granulation (lipozyme TL IM; Novozymes A/S, Bagsvaerd, Denmark), has recently been developed for fat modification. This study focuses on the new characteristics of the lipase in a packed‐bed reactor when applied to interesterification of TAG. The degree of reaction was strongly related to the flow rate (residence time) and temperature, whereas formation of hydrolysis by‐products (DAG and FFA) were only slightly affected by reaction conditions. The degree of reaction reached equilibrium at 30–40 min residence time, and the most suitable temperature was 60°C or higher with respect to the maximal degree of reaction. The lipase was stable in a 2‐wk continuous operation without adjustment of water content or activity of the column and the substrate mixture.