In cellulose, there are several alcohol groups - the two on the ring being secondary alcohols, and the one on the branch being a primary alcohol. I would expect all of these to be oxidised in the presence of any oxidising agent, such as heating under reflux with acidified potassium dichromate - this would give an aldehyde, and then a carboxyl group on the branch, whilst the two on the ring would be oxidised to ketones. However, as you can see in the diagram below (ignoring the sulfonation step which is irrelevant to the question), this is not the case with cellulose.
Further to this, the oxidation of these groups in paper causes discolouration. Is this because the double bonded oxygen atom then joins the delocalised system, increasing the size of the chromophore and hence bringing the frequency at which the material absorbs into the visible region? Or is there a different reason?