Intermittent frying effect on French fries in palm olein, sunflower, soybean and canola oils on quality indices, 3-monochloropropane-1,2-diol esters (3-MCPDE), glycidyl esters (GE) and acrylamide contents

This study was carried out to determine the effect of intermittent frying of French fries using four different types of frying media on the media quality as well as 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters (GE) in frying oils and acrylamide contents in finished product. A total of 80 h of heating (control) and frying experiments at 180 °C was conducted, from which the heated and frying oil samples, as well as French fries were collected every day for 10 consecutive days. The oil samples were subjected to oil quality assessment as well as 3-MCPDE and GE in oils and acrylamide content in fried foods. A significant reduction of more than 80% in the 3-MCPDE content of palm olein was observed as compared to the other oils. The final 3-MCPDE levels in all oils were below 0.5 mg kg−1; whilst the GE levels were between 0.5 and 2.0 mg kg−1. For acrylamide analysis, oil type and lipid oxidation profile play an important role in the acrylamide concentration in the fried products. As for oil quality parameters, palm olein showed better frying performance due to the fact that it contains balanced proportion of saturated and unsaturated fatty acid composition. Edible oils with high unsaturated fatty acid are more susceptible to oxidation. In general, frying conditions affect the formation of 3-MCPDE and GE in all oils under extended frying time.