The best foods for long-term storage are freeze dried items prepared to US Military specifications, sealed in tins. Outer cardboard packaging should be shrink-wrapped in plastic and treated to protect against moisture, rodents and insects.
Properly prepared goods maintain their taste and nutrition for up to 30 years, but not all brands are equal. Mountain House and Oregon Freeze Dried Foods are two suppliers to the US military who have been in business for many years and their shelf life has been verified both by the military and through independent lab tests.
With suppliers recently new to the business your mileage may vary.
Flexible aluminized Mylar plastic packaging is OK for a few years, but not for long term storage. It is necessary that such items be over-packed in rigid, rodent and insect-proof containers.
Food storage info from the archive of Howard Godfrey's blog:
http://preparednessadvice.com/food_stora...3T6LoFdVRo
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