Gravimetric determination of ethoxylated mono- and diglycerides in bread

A gravimetric method is described for the quantitative determination of ethoxylated mono-and diglycerides (EMGs) in bread at levels as low 0.42% (dry sample). The air-dried pulverized samples are Soxhlet-extracted 22 h with an azeotropic mixture of n-propanol-water. The contents are evaporated to dryness, and then treated with 5% HCl in methanol to trans-esterify the fatty acids present which are then removed by petroleum ether extraction. The EMGs are subsequently precipitated from aqueous solution with phosphomolybdic acid in the presence of barium ions. The precipitate is weighed and compared with known amounts of standard carried through the same procedure.