Deoxybenzoin Impurity

I've had some deoxybenzoin of approximately 98-ish% purity stored in an amber bottle for many months (but less than a year) and it has also been kept cool, dry, dark, etc. Nevertheless what started out as nice clean white crystals has now taken on a deep orange color and a rather bad smell.

I decided to recrystallize a sample from boiling water to salvage what I could, if anything, and see what the situation was. The orange impurity was completely insoluble in the boiling water, melted somewhere in the range of 90-100C, and formed a liquid layer beneath the water with a dark orange-red color. After separating the deoxybenzoin solution and recrystallizing it I turned my attention back to the impurity, which was now a solid mass at the bottom of my test tube. I did a quick check to see if it was soluble in toluene, which it was.

Anyone have any ideas what this orange substance might be? I assume it is some kind of decomposition/polymerization/oxidation product of deoxybenzoin. I'll do some more tests later when I recrystallize the rest of the batch and isolate more to work with.