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

Dietary-Fibre-Rich Fractions Isolated from Broccoli Stalks as a Potential Functional Ingredient with Phenolic Compounds and Glucosinolates

“…Galactose and uronic acids were found in a higher proportion in TF B , whereas IF B was mainly composed of rhamnose, fucose, arabinose and xylose. The high content of uronic acids in the DF from broccoli stalks deserves a mention, ranging from 30% for DBS to 49.3% for TF B ( Table 2 ); these results are in agreement with those reported by other authors for different parts of broccoli plants and their fibre residues [ 10 , 27 ]. By contrast, Schäfer et al (2017) [ 22 ] reported that arabinose and glucose were the main components of the insoluble fibre obtained from broccoli stalks by methanolysis and acid hydrolysis, respectively, which shows that the extraction method used to isolate the DF from broccoli stalks determines the final composition of the fibre-rich fractions.…”

“…The FAC represents the capacity to retain fat or oil, an attribute that is used in industry to stabilise fatty products and which depends on the chemical and physical structure of the fibre. The highest value was obtained for DBS (4 g of oil/g), being similar to that obtained for broccoli stalk (6.7 g of oil/g) and for an alcohol-insoluble residue from broccoli by-products (4.8 g of oil/g) by other authors [ 10 ]. Regarding the osmotic pressure, the lowest value was obtained for TF B (157 mmol/kg) and the highest for DBS (225 mmol/kg), but none of them should induce diarrhoea after consumption as these values are below the physiological values reported previously (290 mmol/kg) [ 35 ].…”

“…However, the higher WRC and SWC of DBS, when compared with TF B , could be related also to the retention of water by other components, such as starch, since the content of carbohydrates was highest in this sample ( Table 1 ). The WRC values of the samples from broccoli stalks (3.9–8.2 g of water/g) were similar to that reported for a mixture of broccoli stalks and leaves (8.8 g of water/g) [ 1 ] and for the alcohol-insoluble residue from a mixture of broccoli by-products (12.5 g of water/g) [ 10 ]. These results are also similar to those for other fibre-rich ingredients derived from tomato peels (6.7 g of water/g) [ 34 ] and raspberry (5–10 g of water/g) [ 31 ].…”

“…However, our values are higher than those reported for some fruit by-products, such as apple pomace and grapefruit peels: 1.6 and 2.3 g of water/g, respectively [ 30 ]. The SWC of DBS and IF B —17.1 and 20.3 mL water/g, respectively, was higher than the values reported by Rivas et al (2022) [ 10 ], and only TF B showed values similar to those reported by these authors for different DF fractions isolated from broccoli by-products (5–13 mL water/g) [ 10 ].…”

“…There are several studies about the use of plant by-products for the extraction of DF using different methods [ 8 , 9 ], but the extraction of fibre from broccoli by-products has been scarcely investigated. A recent study has described the composition of DF obtained from broccoli by-products (a mix of florets, leaves and stalks) using different extraction methods, but the authors did not investigate the content of antioxidant bioactive compounds that remained in the isolated DF [ 10 ].…”