Effective production of β‐sitosteryl oleate using a highly thermal‐tolerant immobilized lipase in a solvent‐free system

Abstract

Abstractβ‐Sitosteryl oleate, renowned for its diverse beneficial bioactivities, holds significant promise as a potential ingredient in functional foods. This study reports the superior performance of β‐sitosteryl oleate facilitated by lipase UM1 (lipase from marine Streptomyces sp. W007, immobilized on XAD1180 resin) as a biocatalyst in a solvent‐free system, in comparison to commercial enzymes Novozym 435 (lipase B from Candida antarctica, immobilized on a macroporous acrylic resin), Lipozyme TL IM (lipase from Thermomyces lanuginosus, immobilized on a non‐compressible silica gel carrier), and Lipozyme RM IM (lipase from Rhizomucor miehei, immobilized on a macroporous acrylic resin). Remarkably, an over 98% yield was achieved under the optimal conditions: a substrate molar ratio of β‐sitosterol to oleic acid of 1:4, lipase loading of 150 U, and a reaction temperature of 60°C. The process exhibited substantial resilience and effectiveness, maintaining a degree of esterification above 95% even after five recycles. Following this, the synthesis was successfully scaled up by 100‐fold, with the product isolated through molecular distillation and confirmed using ultra‐performance liquid chromatography mass spectrometry (UPLC‐MS) and Fourier transform infrared spectroscopy (FT‐IR) analytical techniques. These results underscore lipase UM1 as a promising catalyst for the industrial‐scale synthesis of β‐sitosteryl oleate, fostering expanded avenues for its utilization in the functional food industry.