Thermal degradation of groundnut oil during continuous and intermittent frying.

The quality of refined groundnut oil, as affected
by frying Poori, was assessed with respect to two types of
frying operations viz., continuous frying and intermittent
frying. Continuous frying was carried out consistently for
8 h, whereas intermittent frying was performed for 2 h
everyday for 4 days for a total of 8 frying hours. The
purpose of the study was to compare the level of
deterioration that occurred during the two operations.
Among the parameters studied, peroxide value (11.3±0.26
meqO2/kg), anisidine value (172.4±2.71), diene value
(1.57±0.095), oxidized fatty acid (2.6±0.17%) and viscosity
(103.8±2.5 mPa s−1), were found to be higher after 8 h due
to intermittent frying. The corresponding values 4.9±0.15,
133.3±0.49, 0.811±0.04, 0.38±0.023 and 81.8±2.02 were
observed in continuous frying. Parameters such as iodine
value, unsaturated fatty acids, saponification value and
smoke point decreased significantly (P<0.5) due to intermittent
frying. Results showed that intermittent frying
caused more quality degradation to GNO than continuous
frying.