Vacuum frying of parsnip slices: Optimization by taguchi and response surface methodology and modeling the kinetics of water loss

Abstract

We examined the optimization feasibility of frying conditions at 3 phases to produce crisp fried parsnip slices. In the first phase, the time of ultrasound-assisted osmotic dehydration, time of pre-drying by microwave, and frying pressure were considered as response-affecting factors and Taguchi technique effectively used in analyzing multiple parameters. The impact of process parameters (frying time, thermal driving force, & slice thickness) over the quality fried features parsnip slices (crispness, oil uptake, & optical features) was examined in the second phase. Cooling was performed in different conditions in the third phase. The vacuum frying’s optimal condition to produce fried parsnip slices was determined (parsnip slice thickness of 4.553 mm, ultrasound-assisted osmotic dehydration (immersed for 60 min in fructose solution), frying at 56.273 °C thermal driving force (146.2 °C) for 2.746 min at 70.1 frying pressure (kPa), & removing surface oil by centrifuging at 1200 rpm for 4 min). In this setting, the breaking force, oil uptake, and total color difference were predicted to be 12.217 %, 21.524 N, and 13.394, respectively. The impact of optimum frying conditions on the frying kinetics of parsnip slices was investigated. According to the findings, the model of Midilli et al. was considered the best.

Keywords

• Deep-fat frying
• Kinetics
• Oil uptake
• Optimization