Soluble fiber
Soluble fiber; the term has never made any sense to me.
If a fiber is truly soluble then it would break up into it’s constituent molecules and the fact that it started life as a fiber would mean nowt.
What they actually mean is ‘water dispersible’ fiber. In water such a fiber would be substantially extended and free of entanglement with it’s brethren.
And only a chemist would care about such definitions.
offshore westerly 
‘Fibre’ here has a nutritional specialist meaning which is a different from the synthetic polymer specialist meaning – both insoluble and soluble fibres in the nutritional sense are water dispersible, but insoluble ones are dispersible as lyophobic colloids, while soluble ones are dispersible as lyophilic colloids. YMMV. 😉