2.2. Obtaining fibre concentrates
All co-products were washed twice with warm water (30 C)
1:1 (v:w) and then dried at 60 C for 12 h in an air tunnel drier before
being ground to a particle size of 220–640 lm.
Materials were then washed under mild conditions to minimise
losses of soluble fibre components (such as pectins and pentosans)
as well as bioactive compounds (such as flavonoids, phenolic acids
and tannins). Washing reduced free sugar and ash contents, while
drying at temperatures below 65 C avoided changes in the functional
properties and in the contents of bioactive compounds.
Grinding to a relative large particle size was done to maintain
the hydration characteristics and the textures of the fibre
concentrates.