Flax is the common name for Linum usitatissimum, a member of the Linaceae Family. Flax, also known as linseed, used to be one of the major sources of cloth fibre (linen) until the cotton industry took over. Flax seed is the source of linseed oil, which is used as an edible oil, as a nutritional supplement and as an ingredient in many wood finishing products.
Flax is native to the region extending from the eastern Mediterranean to India. It was extensively cultivated in ancient Ethiopia and ancient Egypt. Now the most significant linseed producing countries are Canada and China.
Over-heating through cooking can destroy essential fatty acids in foods. Frying is the worst method as the extremely high heat of the oil accelerates free radical oxidation, destroying the essential fats. They may also be leeched out of the food and lost.
Oxygenation of the oil will turn it rancid through free radical production. Products containing unstable oils should be nitrogen flushed to prevent air in the packaging oxygenating and damaging the oil. Alternatively, antioxidants should be added.