Improve the functional properties of dietary fibre isolated from broccoli by-products by using different technologies

The aim of this study was to analyze the chemical composition of leaves, stems and inflorescences obtained from broccoli by-products in order to develop the improvement of the composition and functional properties of DF from broccoli by-products through treatment with different degradation methods, such as modifications with supercritical fluids, enzymatic, autoclave and ultrasound treatment. The results showed that the chemical composition of the different parts of the broccoli by-products, leaves, stems and inflorescences was significantly different, highlighting that the content of insoluble and soluble dietary fibre was higher in the stem. The enzymatic treatments decreased the content of neutral sugars and increased the content of uronic acids, which was related to the increase of specific functional activities. Cellulase and the multi-enzymatic visconzyme complex improved the solubility and glucose adsorption capacity, whereas supercritical fluids treatment improved the swelling, water retention and lipid absorption capacities. The value of non-extractable phenolic compounds was higher in the inflorescences and increased with enzyme and supercritical fluid treatments, as well as the antioxidant capacity. Enzyme treatment also had a greater effect on the stimulation of the growth of the lactic acid bacteria studied and, therefore, reached the highest values in the production of all short-chain fatty acids analysed. Therefore, the use of enzyme treatments of dietary fibre obtained from broccoli by-products improves the functional properties of broccoli fibre.