Differential Bacillus fermentation modifications of bamboo shoot shell dietary fiber: Evaluating physicochemical...

The effects of Bacillus coagulans, B. subtilis, and B. licheniformis fermentation on the physicochemical, structural, and heavy metal adsorption of bamboo shoot shell dietary fiber (BSSDF) were investigated. All samples contained five monosaccharides-xylose, glucose, arabinose, galactose, and rhamnose-in descending order of abundance. After modification, the contents of soluble dietary fiber (SDF) and xylose increased, while glucose content decreased. The BSSDF fermented by B. coagulans (BC-BSSDF) had the highest SDF content (19.92 %). Compared with BSSDF, the particle sizes of BC-BSSDF, BS-BSSDF, and BL-BSSDF decreased by 24.63 %, 12.76 %, and 6.82 %, respectively. The water-holding, swelling, oil-holding, nitrite ion adsorption, and cholesterol adsorption abilities followed the order: BC-BSSDF > BS-BSSDF > BL-BSSDF > BSSDF. The relative crystallinity of BC-BSSDF, BS-BSSDF, and BL-BSSDF decreased by 26.86 %, 21.11 %, and 16.08 %, respectively, in comparison with BSSDF. Thermogravimetric analysis reveals that BL-BSSDF exhibited the highest thermal stability among the modified samples. Scanning electron microscopy showed that Bacillus coagulans created a rougher, more porous surface with greater disruption than the other Bacillus strains, enhancing BSSDF's properties. Moreover, BC-BSSDF had the strongest Cd²⁺ and Pb²⁺ adsorption, with chemisorption being the dominant mechanism in the adsorption process across all four BSSDF samples. This study provides new insights into dietary fiber modification and improves the utilization value of bamboo shoot shells.