>Thiamine in foods can be degraded in a variety of ways. Sulfites, which are added to foods usually as a preservative,[34] will attack thiamine at the methylene bridge in the structure, cleaving the pyrimidine ring from the thiazole ring.[13] The rate of this reaction is increased under acidic conditions. Thiamine is degraded by thermolabile thiaminases (present in raw fish and shellfish[12]). Some thiaminases are produced by bacteria. Bacterial thiaminases are cell surface enzymes that must dissociate from the membrane before being activated; the dissociation can occur in ruminants under acidotic conditions. Rumen bacteria also reduce sulfate to sulfite, therefore high dietary intakes of sulfate can have thiamine-antagonistic activities.
Is this perhaps due to sulfate pollution (bunker oil?) and acidification of the oceans?
The heavy fuel oil sulfur pollution situation has improved in Europe massively since 2015 when the emissions controls started. By now we should see an effect.
>Thiamine in foods can be degraded in a variety of ways. Sulfites, which are added to foods usually as a preservative,[34] will attack thiamine at the methylene bridge in the structure, cleaving the pyrimidine ring from the thiazole ring.[13] The rate of this reaction is increased under acidic conditions. Thiamine is degraded by thermolabile thiaminases (present in raw fish and shellfish[12]). Some thiaminases are produced by bacteria. Bacterial thiaminases are cell surface enzymes that must dissociate from the membrane before being activated; the dissociation can occur in ruminants under acidotic conditions. Rumen bacteria also reduce sulfate to sulfite, therefore high dietary intakes of sulfate can have thiamine-antagonistic activities.
Is this perhaps due to sulfate pollution (bunker oil?) and acidification of the oceans?