Effects of Different Treatments on the Structure and in Vitro Hypolipidemic Function of Soluble Dietary Fiber from Rosa roxburghii Tratt Pomace

Rosa roxburghii Tratt pomace was used as raw material after general grinding (GG), superfine grinding (SG), high-pressure homogenization (HPH), and superfine grinding synergistic high-pressure homogenization (SG-HPH) treatments. Four R. roxburghii pomace soluble dietary fibers (RRTSDFs) were then obtained by enzymatic extraction and named RRTSDF, S-RRTSDF, H-RRTSDF, and SH-RRTSDF. The yield, structure, and in vitro hypolipidemic function of the four dietary fibers were investigated. Compared with general grinding, the other three treatments increased the RRTSDF yield, with the highest yield at 20.48%±0.48% obtained using SG-HPH. The median particle sizes of the four dietary fibers were 19.88 μm<89.49 μm<103.69 μm<107.74 μm for SH-RRTSDF, S-RRTSDF, H-RRTSDF, and RRTSDF, respectively. The microstructural results revealed that SG combined with HPH treatment resulted in porous and wrinkled RRTSDF surfaces. Fourier transform infrared spectroscopy and X-ray diffraction analyses showed that none of the four treatments changed the functional groups and crystalline shape of the RRTSDF. However, the SG, HPH, and SH treatments reduced the thermal stability of the RRTSDF, with the SH-RRTSDF being the least thermally stable. The oil-holding capacity, cholesterol adsorption capacity in simulated gastric and intestinal environments, and adsorption rates of taurocholate and sodium glycylcholate of SH-RRTSDF obtained by ultra-micro-milling in combination with high-pressure homogenization were 4.59 g/g, 4.03±0.21 mg/g (pH2.0), 10.87±0.20 mg/g (pH7.0), 23.69%±0.06% (sodium taurocholate) and 33.37%±0.04% (sodium glycylcholate), respectively. These values were significantly higher than those of the other three pulverization methods. In conclusion, SG-HPH effectively improves the structure and physicochemical properties of RRTSDF, which not only establishes a dependable modification approach for dietary fiber from R. roxburghii, but also provides theoretical guidance for value-added processing of R. roxburghii. © The Author(s) 2025.