Oil absorption mechanism of fried food during cooling process

Abstract

The objective of this study was to investigate critical parameters affecting oil absorption and provide promising clues for reducing oil absorption in the deep-fat fried potato products. Driving forces of oil absorption in deep-fried potato cylinders were analyzed during a post-frying cooling. Results revealed that a pressure difference (Patm - Pv), which was formed by vapor condensation, played a key role in the oil uptake into microstructure of the fried potato products. Based on the experiments conducted in the different vacuum environments, it was found that less oil was absorbed by the potato cylinders when they were cooled under 80 kPa after frying, in which a delayed initiation of oil uptake and a reduced driving force for oil absorption were noticed. Therefore, lowering the pressure difference (P atm - Pv) with pressure-vacuum method can change the equilibrium existing between oil uptakes and adhesion, which promoted the oil drainage at the early stage of cooling period and led to a low amount of oil uptake into the fried food. PRACTICAL APPLICATIONS These results can provide a reference for reducing oil uptake of deep-fat frying process in the food industry. © 2012 Wiley Periodicals, Inc.