Comparative Study of Acrylamide Formation Induced by Microwave and Conventional Heating Methods

In this study, the formation of acrylamide upon treatment with microwave and conventional heating, boiling, or frying was investigated in both Asn/Fru and Asn/Glc model systems and in potato chips. Acrylamide levels were analyzed by HPLC method, which was confirmed by HPLC-MS/MS. Present results in model systems showed that pH value had a complex influence on the formation of acrylamide in the 2 systems during both microwaving (600 W) and boiling (120 ± 1 oC). At pH < 8.0, acrylamide content increased with increasing the pH value, reaching the maximum at pH 8.0 whereas acrylamide content decreased with the increase of pH. Regardless of pH and heating methods, acrylamide content generally increased with increasing treatment time. Surprisingly, all present results showed that microwave heating not only induced acrylamide formation in the 2 model systems but also facilitated more acrylamide to be formed as compared to the boiling method at identical pH and treatment time. At pH 4.0, 8.0, and 10.0, the larger the microwave power, the more the acrylamide content. Consistent with the above observation, treatment of potato chips with microwave heating for 2.5 to 3.5 min in the range 550 to 750 W similarly resulted in acrylamide formation. The highest acrylamide content was formed by 750 W microwave treatment as 0.897 ± 0.099 mg/kg, which was significantly higher than that produced by traditional frying (180 ± 1oC), 0.645 ± 0.035 mg/kg (P < 0.05).