Nutritional targeting modification of silkworm pupae oil catalyzed by a smart hydrogel immobilized lipase

Immobilization of glycosyltransferase into a hydrophilic metal-organic framework for efficient biosynthesis of chondroitin sulfate

Chondroitin sulfate (CS) is a structurally complex anionic polysaccharide widely used in medical, cosmetic and food applications. Enzymatic catalysis is an important strategy for synthesizing CS with uniform chain lengths and well-defined structures. However, the industrial application of glycosyltransferases is hindered by limitations such as low expression yields, poor stability, and challenges in reuse. We developed a mild and rapid one-step synthetic method for the efficient immobilization of chondroitin synthase (KfoC). The resulting KfoC@ZIF-90 composite exhibits high catalytic activity, thermal stability, and pH adaptability. Notably, KfoC@ZIF-90 exhibited 5-fold enhanced thermal stability at 40°C and retained 86 % relative activity at pH 10, while also maintaining 90 % activity in organic solvents, surpassing the performance of free KfoC. Molecular docking analysis revealed that the binding capability of encapsulated KfoC with substrate was stronger than that of free KfoC, thereby improving catalytic performance. Furthermore, KfoC@ZIF-90 can be easily separated from the reaction solution by centrifugation, simplifying product isolation and purification while enabling enzyme reuse. These attributes significantly enhance operability and reduce processing costs, making enzymatic CS synthesis more feasible for industrial applications.

Computer-Aided Lipase Engineering for Improving Their Stability and Activity in the Food Industry: State of the Art

As some of the most widely used biocatalysts, lipases have exhibited extreme advantages in many processes, such as esterification, amidation, and transesterification reactions, which causes them to be widely used in food industrial production. However, natural lipases have drawbacks in terms of organic solvent resistance, thermostability, selectivity, etc., which limits some of their applications in the field of foods. In this systematic review, the application of lipases in various food processes was summarized. Moreover, the general structure of lipases is discussed in-depth, and the engineering strategies that can be used in lipase engineering are also summarized. The protocols of some classical methods are compared and discussed, which can provide some information about how to choose methods of lipase engineering. Thermostability engineering and solvent tolerance engineering are highlighted in this review, and the basic principles for improving thermostability and solvent tolerance are summarized. In the future, comput er-aided technology should be more emphasized in the investigation of the mechanisms of reactions catalyzed by lipases and guide the engineering of lipases. The engineering of lipase tunnels to improve the diffusion of substrates is also a promising prospect for further enhanced lipase activity and selectivity.

The enzymatic synthesis of EPA-rich medium- and long-chain triacylglycerol improves the digestion behavior of MCFA and EPA: evidence on in vitro digestion

Medium-chain triglyceride (MCT) and eicosapentaenoic acid (EPA) have been widely applied in nutritional supplementation. However, when administered individually or mixed, they were unable to maximize their nutritional value. Hence, EPA-rich medium- and long-chain triacylglycerol (MLCT) was synthesized from MCT and EPA-rich fish oil (FO) by enzymatic transesterification. The fatty acids in triglyceride (TAG) were rearranged which resulted in significant changes in TAG profiles compared to the physical mixture of MCT and FO (PM). EPA-containing MML (MML, MLM and LMM) and LLM (LLM, LML and MLL) type TAGs account for 70.21%. The fate of different oils (MCT, FO, PM, and MLCT) across the gastrointestinal tract was subsequently simulated using an in vitro digestion model. The results showed that the physical and structural characteristics of different oils during digestion depended upon the oil type and the microenvironment they were in. After 120 min of small intestine digestion, the degree of hydrolysis for MLCT was higher than that for the other three oils. The final FFA release level was in the following order: MLCT (102.79%) > MCT (95.20%) > PM (85.81%) > FO (74.18%). This can be attributed to the composition and positional distribution of fatty acids in TAGs. What's more, LCFAs (EPA) in MLCT mainly existed in the form of sn-2 MAG, which was conducive to their subsequent absorption and transport. These results may aid in the future rational design of structural lipids, thereby regulating lipid digestion and maximizing the nutritional value of oils.