The application of pretreatments for producing low-fat fried foods: A review

Consumption of edible oils and saturated fats in high amounts is linked with numerous health issues. Consumer demand for high-quality, healthy foods has led to continuous attempts to produce fried products with less fat content. Different pretreatments such as batter and breading coatings, ultrasound, blanching, freezing, pulsed electric fields, microwave, hot-air drying, and osmotic dehydration have been applied before frying to lower oil absorption. There are some review articles in the literature about frying food products, mainly on a single frying technique such as vacuum frying, single food such as French fries, and single pretreatment such as coating with hydrocolloids. This review covers all the available pre-frying treatments to reduce oil absorption during various frying techniques, including batter and breading coatings, ultrasound, blanching, heating, freezing, pulsed electric field, drying, and combined methods, including vacuum, hot-air, microwave, and ultrasound as well as drying, coating, and pulsed electric fields. Due to considerable thermo-gelling characteristics, hydrocolloids are widely used to lower oil absorption during the frying process. The high dehydration effectiveness of ultrasound has resulted in its application to reduce oil uptake during frying. Besides, blanching leads to develop food products with low moisture, lowering frying time and oil absorption. Heating and drying alter the structural properties of foods and, by crust formation, decrease oil uptake. Moreover, the pulsed electric field intensifies the porosity of foods, leading to enhanced movement of water vapors, leading to the development of lower voids for oil absorption.