Effects of different extraction methods on structure and functional characteristics of soluble dietary fiber from Dendrocalamus brandisii Munro shoots

The extraction of soluble dietary fiber (SDF) from bamboo shoots was influenced by various techniques, including enzyme extraction (E), ultrasound-assisted enzyme extraction (UE), deep eutectic solvent extraction (D), and ultrasound-assisted deep eutectic solvent extraction (UD). While these methods were known to impact the yield and functional properties of SDF, it remained unclear how different extraction techniques affect the efficiency of SDF's bioactivity at the molecular level. In this study, we used a comparative approach to assess the physicochemical properties, microstructure, and functional properties of SDF obtained by these extraction methods. The results showed that UE-SDF achieved the highest yield (9.72 +/- 1.01 g/100 g). Compared to E-SDF and D-SDF, both UE-SDF and UD-SDF exhibited a porous structure, lower molecular weight, and lower crystallinity after ultrasonic pretreatment, significantly enhancing their physical and chemical properties. Notably, UE-SDF demonstrated the best in vitro antioxidant effect and thermal stability, whereas UD-SDF excelled in water-holding, oil-holding, swelling, and bile acid adsorption capacities. In addition, significant differences in monosaccharide composition and molecular weight were observed between the four SDFs. Overall, our study provided valuable insights into how different extraction techniques affected the bioactivity of bamboo shoot-derived SDF, highlighting potential applications in the food industry.