...Other oxidation reaction...
Patents for the oxidation of sulfites began appearing as early as 1965.when Bloch propoed the use of bisulfite salts in cloth or paper bags for insertion into cans. This patent wae assigned to the US government. He saw the need for prevention of oxidation of dehydrated products in particular,and noted the capability of a variety of sulfite froms to be useful in the presence of an acid such as lactic acid.The reactions required the presence of water and thir could be added,even though some might be available as waterof crystallization in one or more of the salts.It is clear that the use of oxidase enzymes was already being discussed, and Bloch noted the reactivity of bisulfites at refrigerator temperatures when enzymes were ineffcint.It is interesting to note that that he recognized the need for intimate mixing of the bisulfite with an activator such as an iron salt,particularly in the presence of a porous support such as carbon or silica gel.Another useful feature was his recommendation of the inclusion of a carbonate sale to release carbon dioxide to maintatain pressure in flexible packe as the oxygen is removed. Most of these considertions are emphasized in the more recent literature of oxygen is absorers. Perhaps most important was his recognition that the relative rates of bisulfite oxidation and food important was his recognition that the relative rates of bisulfite oxidation and food degradation might be different.