I mentioned this bag back in April. I bought a bag of the chips this weekend and what I didn't mention earlier was this: it is a seriously LOUD bag. There is no chance that you will be able to sneak a few chips from this without anyone knowing.
The noise reminds me very much of the noise that you get from a polyester blister pack - minus the cussing from the individual attempting to open the package! Polylactic acid (PLA) is a polyester (aliphatic instead of aromatic) but still, polyester linkages unite the monomers along the backbone. I'm not sure that I want to go out on a limb and attempt to correlate noise profiles with specific linkages however.