Abstract

Acrylamide formation in French fries was investigated in relation under different processing conditions and the content of glucose and asparagine of the strips before frying. Potato strips (0.8 × 0.8 × 5 cm) of Bintje variety were fried at 150, 170 and 190 °C until reaching moisture contents of ∼40 g water/100 g (total basis). Prior to frying, potato strips were treated in one of the following ways: (i) immersed in distilled water for 0 min (control), 60 min and 120 min; (ii) immersed in a citric acid solution of 10 g/L for an hour; (iii) immersed in a sodium pyrophosphate solution of 10 g/L for an hour; (iii) blanched in hot water at six different time-temperature combinations (50 °C for 40 and 80 min; 70 °C for 10 and 45 min; 90 °C for 3 and 10 min). Acrylamide content was determined in French fries while the glucose and asparagine content in the potato strips before frying. Immersed strips in water for 120 min showed a reduction of acrylamide formation of 33%, 21% and 27% at 150, 170 and 190 °C, respectively, when they were compared against the control. Potato strips blanched at 50 °C for 80 min had the lowest acrylamide content when compared against strips blanched at different conditions and fried at the same temperature (135, 327 and 564 μm acrylamide/kg for 150, 170 and 190 °C, respectively). Potato strip immersion in citric acid solution of 10 g/L reduced much more the acrylamide formation after frying than the strip immersion in sodium pyrophosphate solution of 10 g/L (53% vs. 17%, respectively-average values for the three temperatures tested). Acrylamide formation decreased dramatically as the frying temperature decreased from 190 to 150 °C for all the pre-treatments tested. Color represented by the total color difference showed high correlation (r 2 of 0.854) with the acrylamide content of French fries. © 2006 Elsevier Ltd. All rights reserved.