Effects of Microwave Pretreatment on Qualitative Characteristics of French Fries during Deep Fat Frying

Potato fried, despite their large proportions of oil and adverse effects on health, are one of the most popular products in the food industry. Therefore, decreasing oil absorption during frying can be an important goal of French fries processing. In this study, effects of microwave pretreatment on oil absorption and qualitative characteristics of potato fries during deep frying were investigated.

Potatoes were stored in refrigerators at temperatures higher than zero (4 ℃ ) for 24 h before beginning the experiments. Microwave pretreatment was used with powers of 200, 300, 400 and 500 W and times of 2, 4 and 6 min and the frying process was carried out at temperatures of 160 and 180 ℃ . Furthermore, moisture content, oil absorption, color component, texture hardness and, shrinkage of the samples were assessed as well as sensory evaluation of the samples.

Microwave pretreatment included significant effects on moisture content, absorbed oil, color indices and texture hardness of the samples (p < 0/05) with no effects on shrinkage (p > 0/05). Of various treatments, the greatest effect was observed with the power of 500 W for 6 min at 160 and 180 ℃  (8.105 and 11%).

Results showed that at higher powers and times, the intensity of decreases in oil absorption increased. It can be concluded that use of microwave is an appropriate, easy available pretreatment to decrease oil content and improve quality characteristics of potato fries.