Biology subjects

Khongkomolsakul, W.

Publications and source records attributed to Khongkomolsakul, W..

3 recordsLinked to original sources

bioRxiv2025

Core-shell microparticle encapsulation for pH-responsive and targeted delivery of lactoferrin and ferrous sulfate

Microgel beads of amidated low methoxy pectin and bovine lactoferrin were formed by external gelation of a water in oil emulsion with ferrous sulfate. The stability of the lactoferrin to gastric digestion and proteolysis by pepsin was determined by gel electrophoresis. The microparticles were then dispersed in chitosan and the resulting mixture was spray dried to form a shell that is insoluble at neutral pH conditions. The iron content of the microparticles without chitosan was 34 mg g-1 and with chitosan was 27 mg g-1. The addition of chitosan lead to reduced iron release at pH 7 (30%) compared to 60% iron release without chitosan, but did not prevent iron from releasing in acidic conditions (pH 1). The core shell microparticle system shows promise as an iron fortificant in food applications.

biochemistry↗

bioRxiv2025

Improving Thermal and Gastric Stability of Phytase via pH Shifting and Coacervation: A Demonstration of Bayesian Optimization for Rapid Process Tuning

Phytase (phyA) breaks down phytate, which can help with nutrient absorption in a plant-based seed diet or high-phytate food. Unfortunately, it is prone to denaturation at food preparation temperatures and is easily inactivated by pepsin during gastric digestion. To protect phyA for use in high-temperature processes (100 {degrees}C) and gastric digestion, chitosan (CS) was used to complex phyA. Bayesian optimization, a machine learning technique, was used to demonstrate how to expedite the optimization process. Thermal stability of the optimized complex increased from 20% (Control: phyA in the native state) up to 74% at 4:1 CS to phyA (CS-phyA) complex and 52% at the 1:1 CS-phyA complex as measured by phytase activity assay. Chitosan complexation also improved the retention of enzyme activity after thermal and gastric digestion by 13-fold, retaining residual activity at 40% for the 4:1 CS to phyA and 22% for the 1:1 CS-phyA complexes compared to the enzyme itself, which only retained 3% residual activity. Molecular docking and circular dichroism were used to investigate the underlying interaction mechanism between CS and phyA and the secondary structure of the enzyme after heat treatment. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) confirmed the complexation of phyA with CS and revealed complex morphology. With improved enzyme stability, there is great potential for efficiently expanding phytase applications in a high plant-based seed food matrix. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=121 SRC="FIGDIR/small/649602v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@889b76org.highwire.dtl.DTLVardef@969ed3org.highwire.dtl.DTLVardef@953e55org.highwire.dtl.DTLVardef@2f5864_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIThermal stability of phytase improved from 20% to 74% using chitosan C_LIO_LIpH shifting increased enzyme complexation efficiency and thermal stability (100 {degrees}C) C_LIO_LIBayesian optimization (BO) is a promising optimization tool for complexation conditions C_LI

biochemistry↗

bioRxiv2025

Core-Shell Hydrogel System to Protect the Enzyme Activity of Phytase from Environmental Stress

Fortification of phytase from Aspergillus niger (phyA) in a vegetarian diet is a practical strategy to solve mineral deficiencies induced by the presence of phytate. To protect phyAs activity and retention from environmental stress such as heat and acidic conditions, we evaluated the use of a core-shell hydrogel bead, where the core is composed of a phyA-chitosan complex, and the shell is formed by cross-linking alginate with {kappa}-carrageenan. The phyA loading capacity is 52.2%, with high encapsulation efficiency (82.6%). When forming the hydrogel beads, a needle diameter of 0.5 mm can create a 2.5 mm bead. The beads were found to remain intact during dehydration under a vacuum at 30 . The formed hydrogel beads protected 79.7% of the phyA activity after heating at 100 {degrees}C for 12 min. The beads protected their cargo against salt, pH changes, and protease. These results suggest that core-shell beads are suitable for protecting enzyme activity against various processing stresses, which makes them useful as a delivery method for phytase in food applications.

biochemistry↗