You would think that everybody can taste and smell food, but some of us are much better at it than others, says Jena Roberts, vice president for business development at the NFL. The lab has 40 of these food tasters on staff.
http://www.npr.org/sections/thesalt/2012/12/26/167819082/dont-fear-that-expired-food
Preparing and Cooking Food. One of the basics of food safety is cooking food to its proper temperature. Foods are properly cooked when they are heated for a long enough time and at a high enough temperature to kill the harmful bacteria that cause foodborne illness. Minimum Cooking Temperatures. Meat and Poultry Roasting Chart.
https://www.foodsafety.gov/keep/charts/index.html
Canning low acid vegetables (like green beans and corn), meats, fish and poultry requires the use of a pressure canner. The safe canning methods available for home canning are all based on pressure canning. Clostridium botulinum can form spores that are very, very heat resistant.
https://www.foodsafety.gov/blog/home_canning.html
A best-before date applies to the quality of the product. It is safe to purchase and consume the product after its best-before date, however the food may not be at its peak quality. Read more about use-by and best-before dates. Canned foods that have a shelf-life of more than two years do not need a best before date. As long as the container remains intact, canned foods have a long shelf life even at room temperature. The sealed containers prevent contamination of food by organisms that can spoil the contents or cause illness to people.
http://www.foodstandards.gov.au/consumer/safety/cannedfoods/pages/default.aspx
Canned food, in particular, can stay safe for a really long time. In 1974, scientists at the National Food Processors Association in Washington, D.C., got their hands on several old cans of food. Janet Dudek, now semi-retired and living in Vienna, Va., was among the scientists who analyzed this old food.
http://www.npr.org/sections/thesalt/2012/12/26/167819082/dont-fear-that-expired-food
Home Canning: Keep Your Family Safe! Home canning—what better way to enjoy the fruits of your labor and save money? National movements to promote home canning are gaining momentum, and people are returning to home canning after years away or starting to can for the first time. In fact, according to one survey, 1 in 5 U.S. households can their own food, and many of those households can vegetables.
https://www.foodsafety.gov/blog/home_canning.html
A best-before date applies to the quality of the product. It is safe to purchase and consume the product after its best-before date, however the food may not be at its peak quality. Canned foods that have a shelf-life of more than two years do not need a best before date.
http://www.foodstandards.gov.au/consumer/safety/cannedfoods/pages/default.aspx
Foods are properly cooked when they are heated for a long enough time and at a high enough temperature to kill the harmful bacteria that cause foodborne illness. 1  Minimum Cooking Temperatures. 2  Meat and Poultry Roasting Chart. 3  Ham Cooking Chart.  Turkey Thawing 1  Chart. Turkey Roasting Chart.  Alternative Ways to Cook Turkey.
https://www.foodsafety.gov/keep/charts/index.html
Canned goods: Most expiration dates on foods in cans range from 1 to 4 years—but keep the food in a cool, dark place and the cans undented and in good condition, and you can likely safely double that shelf life from 3 to up to 6 years. Restock your kitchen with the Best Canned and Jarred Goods for Men.
http://www.foxnews.com/health/2014/03/16/which-expired-foods-are-okay-to-eat.html
And that food might not smell bad as it might have arrived in the store only yesterday. In 40 years, in eight countries, if I think of major product recalls and food poisoning outbreaks, I can't think of [one] that was driven by a shelf-life issue, Ruff says.
http://www.npr.org/sections/thesalt/2012/12/26/167819082/dont-fear-that-expired-food
how long is canned food safe
Canned food can be safe for at least 1 to 4 years.  Canned food is safe for 1 to 4 years.