Vegetables that were too unripe or mature when picked causing poor re-hydration and taste. Rice with too much polish which foamed during cooking. Many times these poor products are returned to the market only to be resold to other users and tucked away in cans, never to be discovered until years later. The Perma-Pak cannery is also one of the leading national dehydrator's of fruit and processes large amounts for companies such as Pillsbury, Quaker Oats, Heinz, Kellogg's and many others. Perma-Pak brand food products are only a small portion of their yearly volume.
Many small canneries have no quality control technicians.
It's those quality control technicians which refused the twelve truckloads of bulk material, mentioned earlier, that would not pass their inspection. If tests were not conducted by trained quality control technicians, this merchandise would have been canned, sold, and stored by people who were relying on it for their storage needs. Dehydrated foods ire often canned in sealed containers from which most of the residual oxygen has been removed and replaced with nitrogen. Newer technology also adds oxygen absorbing packets. When canned in this way, most foods sustain higher levels of vitamin stability than is possible with other canning methods.