Producing lower-calorie deep fat fried French fries using infrared dry-blanching as pretreatment

The main objectives of this work were to study the suitability of using infrared (IR) heating as a dry-blanching pretreatment prior to frying and to investigate its potential to reduce the oil uptake in French fry production. It was observed that by using IR heat complete inactivation of polyphenol oxidase enzyme could be achieved in 3 min with 4.7% moisture loss for 9 mm French fries. Following IR dry-blanching, the samples were fried at 146, 160, and 174 °C for 1, 3, 5, and 7 min. At the end of 7 min frying, compared to unblanched samples, dry-blanched samples had 37.5%, 32% and 30% less total oil at the frying temperatures of 146, 160 and 174 °C, respectively. The final moisture contents of unblanched and dry-blanched samples were between 50% and 60% after 7 min frying. The L*a*b* colour values of both unblanched and dry-blanched samples decreased initially and then increased as the frying progressed. The sensory evaluation revealed that panelists mostly favored the IR dry-blanched French fries in terms of taste, texture, colour and appearance.