ARS | Publication request: Producing lower-calorie deep fat fried french fries using infrared dry-blanching as pretreatment

Submitted to: Journal of Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 18, 2011
Publication Date: May 15, 2012
Repository URL: http://dx.doi.org/10.1016/j.foodchem.2011.10.055
Citation: Bingol, G., Ang, Z., Pan, Z., Mchugh, T.H. 2011. Producing lower-calorie deep fat fried french fries using infrared dry-blanching as pretreatment. Journal of Food Chemistry. 132(2):686-692. DOI:10.1016/j.foodchem.2011.10.055.

Interpretive Summary: A global shift in diet towards increased intake of energy-dense foods that are high in fat and sugars but low in vitamins, minerals and other micronutrients is among the major reasons of obesity. Therefore, eating low calorie foods is important in controlling the body weight. Approximately half of the calories of French fries are due to its fat content. This study investigated the use of infrared energy to pretreat potato strips prior to deep fat frying. We found that the oil content of French fries could be reduced up to 37.5% depending on the frying temperature. The taste, texture, color and appearance of infrared pretreated French fries were favored by panelists in sensory evaluation.

Technical Abstract: 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. We 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 50-60% after 7 min frying. The L*a*b* color values of both unblanched and dry-blanched samples decreased initially and then increased as the frying progressed. The sensory evaluation showed that panelists mostly favored the IR dry-blanched French fries in terms of taste, texture, color and appearance.