Gas chromatographic investigation of acrylamide formation in browning model systems

Acrylamide formed in browning model systems was analyzed using a gas chromatograph with a nitrogen-phosphorus detector. Asparagine alone produced acrylamide via thermal degradation at the level of 0.99 mug/g of asparagine. When asparagine was heated with triolein-which produced acrolein at the level of 1.82 +/- 0.31 (n = 5) mg/L of headspace by heat treatment-acrylamide was formed at the level of 88.6 mug/g of asparagine. When acrolein gas was sprayed onto asparagine heated at 180 degreesC, a significant amount of acrylamide was formed (114 mug/g of asparagine). On the other hand, when acrolein gas was sprayed onto glutamine under the same conditions, only a trace amount of acrylamide was formed (0.18 mug/g of glutamine). Relatively high levels of acrylamide (753 mug/g of ammonia) were formed from ammonia and acrolein heated at 180 degreesC in the vapor phase. The reaction of acrylic acid, which is an oxidation product of acrolein and ammonia, produced a high level of acrylamide (190 000 mug/g of ammonia), suggesting that ammonia and acrolein play an important role in acrylamide formation in lipid-rich foods. Acrylamide can be formed from asparagine alone via thermal degradation, but carbonyl compounds, such as acrolein, promote its formation via a browning reaction.