Portal de Periódicos da CAPES

VISCOSITY and SURFACE TENSION of CORN OIL AT FRYING TEMPERATURES

1995; Wiley; Volume: 19; Issue: 4 Linguagem: Inglês

10.1111/j.1745-4549.1995.tb00293.x

1745-4549

Marta Gomes Da Silva, R. Paul Singh,

Food Chemistry and Fat Analysis

Surface active properties and viscosity changes of corn oil were determined under controlled frying conditions. Viscosity of corn oil was measured at a temperature range of 100–200C. Surface-active properties of thermally degraded corn oil were determined by measuring the stationary contact angle () of oil droplets placed on a low energy surface (polystyrene). the viscosity of oil decreased as temperature increased. At 200C, the kinematic viscosity had decreased 69% when compared with its initial value of 7.50 mm2/s at 100C. Oil was degraded by frying 400 g of potatoes for 5 min each hour for 36 h (low load frying). the experiment was repeated with 1200g of potatoes (high load frying). the viscosity of the oil increased 9.4% and 28.6% for low and high load fryings, respectively. the surface tension of the oil and its degradation time were inversely proportional (at high load frying) lowering the surface tension of the oil by 2.0%. A high correlation (r2= 0.90) between the viscosity and surface tension of oil was obtained.