Can chitosan affect the absorption of unsaturated fatty acid?
It seems that there is no difference in the effects of chitosan on the uptake of saturated and unsaturated fatty acids. The study cited below (which has been done on guinea pigs) fed the animals a diet which contained different digestion-resistant fibers (maltodextrin, cellulose and chitosan) and also fats. Then the fatty acid content of the feces was measured afterwards.

Only for the group which got additional feeding of chitosan showed a significant increase in the excreted fatty acids. This was true for the saturated (lauric, myristic and palmitic acid) but also for the unsaturated fatty acids (Oleic, linoleic and α-linolenic acid). This effect is specific for fatty acids, The uptake of neutral sterols and bile acids was not affected in any of the experimental groups.

The second paper suggests that chitosan forms an emulsion with fatty acids under the acidic conditions of the stomach. This emulsion is stable and later excreted with the feces.

References:


Selective in vivo effect of chitosan on fatty acid, neutral sterol
and bile acid excretion: a longitudinal study.
Interaction between chitosan and oil under stomach and duodenal
digestive chemical conditions.