I've been finding brown-ish crumbly looking parts in spaghetti noodles Why is that?

I live alone, so of course I can't single-handedly finish a whole bag of pasta in one sitting, so I usually reseal the bags very well with tape. Still, though, I find strange looking areas randomly on different noodles. Usually I don't even find the spots until I have already put the spaghetti in the pan. What does this mean?