Recent advances in microstructure characterization of fried foods: Different frying techniques and process modeling

Background: Due to the increasing trend in consumer habits to use healthy food products with low fat content, reduction of oil uptake during different frying processes is necessary. Recent studies have clearly revealed that microstructural changes occurred during frying operations significantly impact oil uptake. These variations are assessed for better comprehension of the mechanisms involved in oil absorption of fried products to minimize oil uptake without sacrificing organoleptic and textural properties of the foods. Different strategies such as state-ofthe-art computational simulations based on numerical analysis of simultaneous momentum, heat and mass transfer modeling during frying have been attempted by several researchers to better control the process. Scope and approach: This review paper presents a comprehensive and up-to-date review of microstructure variations covering all existing methods of frying operations comprising deep-fat frying, vacuum frying, hot-air frying, non-fat frying and microwave frying together with post-frying treatments and process modeling of frying. Key findings and conclusions: Oil uptake can be controlled during frying by proper process design regarding different products and frying operations. Textural and organoleptic characteristics of fried foods are affected by applying various frying processes. Microstructural changes and post-frying treatments influence oil uptake during frying. In addition, suitable design and optimization of frying using process modeling is important to produce fried food products with high quality.