Pressure Effect on Deep Fat Frying of Apple Chips

Abstract

Predicting moisture loss is important when developing a model for vacuum frying, because one of its objectives is to remove food moisture. A diffusion model was considered to describe moisture transfer during vacuum frying. Granny Smith apple slabs were processed at 16.6, 13.3, and 8 kPa and between 80 and 120°C. Moisture diffusivity was determined, obtaining a close fit between the model and the experimental data. Diffusivity increased with temperature and decreased when pressure increased. A direct proportionality between heat and mass transfer was observed. Temperature influence was interpreted by the Arrhenius relationship and there was no observed effect of pressure on the activation energy.

Keywords:

• Apple
• Diffusion
• Frying
• Vacuum
• Water loss

ACKNOWLEDGMENT

This work was supported by the European Commission Alfa II Contract AML/B7-311-97/0666/11-0121-FA.

Notes

^a Data at 101.3 kPa from Bravo et al.^{[ 22 ]}.