Innovative pressure-controlled modification of insoluble dietary fiber from Dendrobium Devonianum Paxt stem residues: Enhancing functional properties through differential pressure explosion puffing

Differential pressure explosion puffing regulated fiber structure from DPSR. • Puffing converted insoluble dietary fiber from a compact structure to a porous architecture. • Treatment at 1.0 MPa achieved optimal balance between structural disruption and functionality. • Modified insoluble dietary fiber showed improved hydration and nitrite and cholesterol adsorption. • Electronic structure analysis revealed pressure-induced weakening of intermolecular interactions. This study investigated the modification of insoluble dietary fiber (IDF) from Dendrobium devonianum Paxt stem residues (DPSR) using differential pressure explosion puffing (DPEP). IDF samples were treated at different puffing pressures (0.6, 0.8, 1.0, 1.2, and 1.4 MPa), and their structural characteristics, physicochemical properties, and functional adsorption capacities were systematically evaluated. DPEP transformed the compact IDF matrix into a loose and porous structure, accompanied by reductions in particle size, molecular weight, and crystallinity, while preserving the basic polysaccharide backbone. These structural changes improved the water-holding and swelling capacities of IDF. Among the tested pressures, 1.0 MPa provided the best balance between structural disruption and functional enhancement, reducing the median particle size (D50) from 197.65 μm to 82.01 μm and increasing the water-holding capacity to 8.52 g/g. The functional adsorption properties were also enhanced. IDF-1.0 showed the highest nitrite ion adsorption capacity at pH 2.0 (6.49 μg/g), the strongest cholesterol adsorption capacity at pH 7.0 (0.11 mg/mL), and a glucose adsorption capacity of 22.77 mmol/g. Electronic structure analysis further showed that the degree of electron sharing and integrated crystal orbital Hamilton population of xylose reached their minimum values at 1.0 MPa, indicating that pressure-induced weakening of intermolecular interactions was associated with structural loosening. These findings indicate that DPEP is a promising physical strategy for improving the functionality of plant-derived IDF and provides a new route for the high-value utilization of medicinal-edible plant by-products in functional food applications. Download: Download high-res image (339KB) Download: Download full-size image