Today I bought a Jack Links beef jerky from a vending machine, and when I bit into it I got a distinct taste of something acrid and soapy. As far as I could tell the packaging was not damaged and the jerky was not rotten or spoiled. I have also had this experience once before with a package of fruit snacks, Welch's brand I believe, and when one of the pieces had a spot of something blue on it, and had the same horrible soapy taste, but only on the one piece.
My question is, are processed foods sometimes contaminated with cleaning products used to clean equipment in factories? And if so how often does this sort of thing happen?
I have already tried doing a bit of research on Google and have not found much other than a few scientific papers relating to bacterial contamination, but not contamination of cleaning products.