Short answers, pulled from the story.
The French Navy began feeding its sailors meat and fruit preserved in sealed containers in 1806. This initiative was part of a chemical experiment that eventually saved millions of lives through the development of canning.
Nicolas Appert invented the process of canning by discovering that heating food and sealing it in glass jars could prevent spoilage. Louis Pasteur connected the dots between microorganisms and food spoilage in 1864, explaining why Appert's method worked.
Rural Afghanistan uses kangina vessels to store grapes for up to six months by passively controlling gas exchange and water loss. In Odisha, India, rice is buried underground to store it for three to six months during the dry season using the cool, dry conditions of the soil.
The International Agency for Research on Cancer classified processed meat as carcinogenic to humans in 2015. The use of nitrites in curing raises health concerns, and smoking deposits pyrolysis products that act as antimicrobial agents.
Food irradiation exposes food to ionizing radiation such as beta particles or gamma rays to kill bacteria, molds, and insect pests. Irradiated food does not and cannot become radioactive despite consumer fears.
Lactic acid bacteria produce active antimicrobials such as lactic acid, acetic acid, hydrogen peroxide, and peptide bacteriocins. These substances create an environment toxic for other microorganisms and extend the shelf life of food.