IMPACT OF BLENDING OF FRYING OILS ON VISCOSITY AND HEAT TRANSFER COEFFICIENT AT ELEVATED TEMPERATURES

Abstract

ABSTRACT In the present work, the effect of binary blending of five frying oils on kinematic viscosity ( ν ) and convective heat transfer coefficient ( h ) was studied at elevated temperatures (170, 180 and 190C). A Cannon Ubbelhode calibrated capillary viscometer (Cannon Instrument Company, State College, PA) in a custom‐designed and fabricated convective air bath heater and a highly conductive cylindrical metal transducer were used for generating ν and h data, respectively. The value of ν decreased from 3.617 × 10 ‐ 6 to 2.062 × 10 ‐ 6 m 2 s ‐ 1 , and h increased from 221.0 to 301.2 Wm ‐ 2 C ‐ 1 by increasing the aforementioned oil temperatures. A good correlation between ν ( R 2 > 0.996) or h ( R 2 > 0.987) of these frying oils and their selected binary blends with the previously mentioned temperature range was observed. Significant difference ( P < 0.05) was found between different levels of parameters when treatments were compared using Tukey's test. PRACTICAL APPLICATIONS In food engineering applications, the physical properties of foods play an important role in the analysis of process parameters and in the design and fabrication of processing equipment. Determination of kinematic viscosity and convective heat transfer coefficients of frying oils and their selected blends at elevated temperatures are useful from an industrial point of view. In the present work, the effect of blending different edible oils on the kinematic viscosity and convective heat transfer coefficients at elevated temperatures was studied. Because selected blended oils provided lower levels of viscosities and higher levels of heat transfer coefficients, these results may be an attractive proposition in improving the quality of fried products and cost‐effectiveness in the fried food industry.