Cured fish

[4] "Saline salts from this area contained impurities such as nitrates that contributed to the characteristic red colour of cured meats.

The Romans (200 BC) acquired curing procedures from the Greeks and further developed methods to "pickle" various kinds of meats in a brine marinade.

Saltpeter (potassium nitrate) is mentioned as being gathered in China and India prior to the Christian era for use in meat curing...

[8] Nitrates and nitrites have been used for hundreds of years to prevent botulism in fish and ensure microbial safety.

Nitrates help kill bacteria, produce a characteristic flavor, and give fish a pink or red color.

[9] Nitrite is commonly used to speed up the curing of meat and also impart an attractive colour while having no effect on the growth of the Clostridium botulinum bacteria which causes botulism.

A 2007 study by Columbia University suggests a link between eating cured meats and chronic obstructive pulmonary disease.

Smoking helps seal the outer layer of the food being cured, making it more difficult for bacteria to enter.