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Product Formulation for Ohmic Heating: Blanching as a Pretreatment Method to Improve Uniformity in Heating of Solid–Liquid Food Mixtures
Author(s) -
Sarang S.,
Sastry S. K.,
Gaines J.,
Yang T. C. S.,
Dunne P.
Publication year - 2007
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2007.00380.x
Subject(s) - blanching , joule heating , food science , materials science , food products , chemistry , dielectric heating , composite material , dielectric , optoelectronics
The electrical conductivity of food components is critical to ohmic heating. Food components of different electrical conductivities heat at different rates. While equal electrical conductivities of all phases are desirable, real food products may behave differently. In the present study involving chicken chow mein consisting of a sauce and different solid components, celery, water chestnuts, mushrooms, bean sprouts, and chicken, it was observed that the sauce was more conductive than all solid components over the measured temperature range. To improve heating uniformity, a blanching method was developed to increase the ionic content of the solid components. By blanching different solid components in a highly conductive sauce at 100 °C for different lengths of time, it was possible to adjust their conductivity to that of the sauce. Chicken chow mein samples containing blanched particulates were compared with untreated samples with respect to ohmic heating uniformity at 60 Hz up to 140 °C. All components of the treated product containing blanched solids heated more uniformly than untreated product. In sensory tests, 3 different formulations of the blanched product showed good quality attributes and overall acceptability, demonstrating the practical feasibility of the blanching protocol.