Advancements in the Esterification of Phytosterols Catalyzed by Immobilized Lipase

Phytosterol exhibits cholesterol-lowering, cardiovascular-protecting, anti-inflammatory, and anticancer efficacies but has low bioavailability due to its high melting point and poor solubility. Esterification with fatty acids enhances liposolubility, improving absorption and utilization fivefold. Industrial production of phytosterol esters mainly relies on chemical synthesis, which faces challenges in separation, purification, and quality assurance due to side reactions. Enzymatic synthesis, featuring mild conditions, environmental friendliness, and high selectivity, has gained attention from academia and industry. Candida rugosa lipase (CRL) is widely utilized due to its high efficiency in catalyzing the esterification of phytosterol. Natural lipases are highly sensitive to changes in temperature and pH and are difficult to reuse in continuous cycles; however, certain immobilization techniques can improve their catalytic activity and stability. Furthermore, the application of immobilized lipases in the synthesis of phytosterol esters can be combined with ultrasonic treatment to enhance the efficiency of enzymatic catalysis. This paper reviews the research progress on the catalytic esterification of phytosterol by immobilized lipases, highlighting the current challenges and future research directions, thereby fostering further advancements in the field of preparing phytosterol esters through immobilized lipase catalysis. © 2025 by the authors.