Extrusion improved the physical and chemical properties of dietary fibre from bamboo shoot by‐products

Summary Bamboo shoot by‐products are regarded as waste and environmental pollutant. This study aimed to improve the functional properties of dietary fibre from bamboo shoot by‐products. After CO 2 extrusion, the particle size of CO 2 ‐extruded bamboo fibre was 17.6% lower than that of the control, and its specific surface area was 2.85 times that of the control. The soluble dietary fibre content was significantly increased from 5.64 g/100 g to 11.05 g/100 g ( P < 0.05), and the capacities for water holding, swelling and oil holding were remarkably improved. The cholesterol adsorption of CO 2 ‐extruded bamboo fibre was increased from 96.54 μg g −1 to 174.65 μg g −1 (pH 7.0), and its nitrite ion adsorption capacity was increased from 503.33 μg g −1 to 657.27 μg g −1 (pH 2.0). In summary, the structural changes of bamboo fibre such as internal porosity, surface roughening and low crystallinity indicated that its functional properties were improved after CO 2 extrusion.