Relationship between crust characteristics and oil uptake of potato strips with hot-air pre-drying during frying process.

Crust property is an important factor in affecting the oil absorption of potato strips. The present study aimed at illustrating detailed crust characteristics in relation to oil uptake of potato strips during frying as a function of hot-air pre-drying time. Results showed that oil content decreased with the increasing hot-air pre-drying time. Oil distribution determined by LF-NMR and CLSM confirmed pre-drying could reduce oil uptake of potato strips. Structural and textural analysis of crust revealed the increase in crust ratio, roughness and texture (Fm, Nwr, fwr, Wc), and decrease in crust uniformity. Results of microscopic structure unraveled that the crust of fried strips after pre-drying for 180 min became thick and compact with almost no pores. Our results suggested that hot-air pre-drying caused the formation of harder and denser crust, and oil uptake of fried potato strips after pre-drying largely depended on crust texture rather than morphology.