Comparative analysis of the oil absorption behavior and microstructural changes of fresh and pre-frozen potato strips during frying via MRl, SEM, and XRD.

This paper aimed to clarify the oil absorption behavior and microstructural changes of fresh and pre-frozen potato strips during frying, and to discuss the effects of freeze pretreatment on the oil absorption behavior of potato strips. We investigated the oil distribution; the microstructure changes in the crust, core, and potato strip surface; and the crystal pattern changes in the potato starch during frying by using magnetic resonance imaging, scanning electron microscopy, and X-ray diffraction. We monitored the profile histories of the moisture, oil and potato strip temperature, and oil uptake during frying and cooling. Results showed that during frying, the diversification of oil content in potato and oil infiltration path was closely related to the microstructure, moisture content, and temperature changes of potato strips and the interaction between starch and oil components. Moreover, freeze pretreatment significantly decreased the moisture content (P < .05) and increased oil content (P < .05) of potato strips and affected oil infiltration, microstructural changes, and starch crystallinity (P < .05) during frying. This paper may help in the further understanding of the oil absorption behavior of potato strips during frying and cooling, and may provide ideas for effective oil control measures.