Interaction of thiol and disulfide flavor compounds with food components

When a commercial savory flavoring containing thiol and disulfide flavor components was heated at 100 degrees C in aqueous solution with egg albumin, considerable changes in the relative concentration of the sulfur compounds were observed. Apparent redox interactions with the protein caused disulfide reduction and formation of the corresponding thiol. Heating bis(2-furanylmethyl) disulfide or bis(2-methyl-3-furanyl) disulfide with albumin in aqueous solution resulted in over 100-fold decreases in disulfide concentrations with a large proportion of the disulfides converted to the corresponding thiols. It is suggested that this was caused by interchange of thiol and disulfide groups with sulfhydryl and disulfide groups of proteins. This was substantiated by observing the effect in water or maltodextrin solutions where no loss of disulfide was observed. In systems containing casein, which has a very low proportion of sulfhydryl groups, only a small amount of disulfide reduction occurred.