Physical properties of pre-treated potato chips

The objective of this research was to study some physical properties of pre-treated potato slices such as moisture and oil content, texture and color during frying at 120, 140, 160 and 180 °C. Slices (Desiree variety, diameter: 30 mm, width: 2.0 mm) blanched in hot water at 85 °C for 3.5 min were considered as the control. NaCl soaked chips were previously blanched as indicated before and immersed in a 3% NaCl solution for 5 min at 200 rpm of agitation and 25 °C. The moisture loss profiles were similar for chips pre-treated in the two ways during frying. Oil uptake increased up to ∼20% as the frying temperature decreased; soaking of blanched chips in the NaCl solution decreased slightly the oil absorption in ∼7%. Color values in L∗a∗b∗ units were recorded at different sampling times during frying at the four mentioned temperatures using the total color difference (ΔE) and a Minolta colorimeter. Soaking of blanched slices in the NaCl solution producer paler chips after chips diminishing the final values of ΔE in 6%, 16%, 9% and 23 % with respect to those corresponding to control chips after frying. Textural changes in fried potato slices were followed by the parameter maximum force (MF). Soaking in NaCl of blanched chips increased its crispness after frying at 120, 140, 160 and 180 °C in 15%, 13%, 11% and 11%, respectively.