Reduction of acrylamide formation in potato chips by low-temperature vacuum frying

Potatoes and other foods that have a high content of the amino acid asparagine and a high accumulation of reducing sugars are subject to the formation of acrylamide upon frying. The objectives of this research were (1) to analyze the level of acrylamide formed during deep-fat frying of potato chips and (2) to evaluate means of reducing acrylamide in potato chips by using different potato cultivars and vacuum frying. Several potato cultivars were used in this research, including Innovator (I), NDTX 4930-5W (N), ATX 854 04-8W (ATw), Atlantic (A), Shepody (S), ATX847806-2Ru (ATr), and White-Rose (W). An electric bench-top (atmospheric conditions)-type fryer was used to fry the potatoes. Three temperatures were used: 150 degrees C, 165 degrees C, and 180 degrees C. The vacuum frying experiments were performed at 118 degrees C, 125 degrees C, and 140 degrees C and a vacuum pressure of 10 Torr. The potatoes were sliced (1.5-mm thick) and fried for different lengths of times. For potatoes fried at 165 degrees C (for 4 min) at atmospheric conditions, the acrylamide contents were 5021 +/- 55 ppb (W), 552 +/- 25 ppb (I), 358 +/- 50 ppb (N), 397 +/- 25 ppb (ATw), 646 +/- 55 ppb (A), 466 +/- 15 ppb(S), and 537 +/- 14 ppb (ATr). Vacuum frying reduced acrylamide formation by 94%. Results showed that both cultivar and modified frying systems can play an important role in reducing acrylamide formation in fried potatoes. As the frying temperature decreased from 180 degrees C to 165 degrees C, acrylamide content in potato chips reduced by 51% during traditional frying and by 63% as the temperature decreased from 140 degrees C to 125 degrees C in vacuum frying. Increased frying time increased acrylamide formation during traditional frying for all temperatures and frying methods analyzed. However, the effect on acrylamide concentration was greater for the traditional frying than the vacuum frying.