Naslov
Determination of thermal conductivity and convective heat transfer coefficient during deep fat frying of "Kroštula" dough

Autori
Šeruga, Bernarda ; Budžaki, Sandra

Izvornik
European Food Research and Technology (1438-2377) 221 (2005), 3-4; 351-356

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Deep fat frying; Heat transfer coefficient; Thermal conductivity; Dough

Sažetak
In this study, the influence of oil temperature, water migration and surface temperature of “ Kroštula” dough on convective heat transfer coefficient was investigated. The convective heat transfer coefficient during deep fat frying was determined at temperatures 160 °C, 170 °C, 180 °C and 190 &plusmn ; ; ; ; ; ; 1°C. Heat transfer coefficient was the highest at the start of deep fat frying process 579.12&plusmn ; ; ; ; ; ; 2.46, 583.88&plusmn ; ; ; ; ; ; 1.81, 597.05&plusmn ; ; ; ; ; ; 1.10 and 657.91&plusmn ; ; ; ; ; ; 0.95 W/m2K for 160, 170, 180 and 190 °C of oil temperature, respectively. The smallest heat transfer coefficient was in the case of setting up a uniform period of water migration from sample, which corresponded to surface temperatures slightly higher than 100 °C 26.53&plusmn ; ; ; ; ; ; 0.63, 14.42&plusmn ; ; ; ; ; ; 0.56, 56.78&plusmn ; ; ; ; ; ; 0.49 and 37.52&plusmn ; ; ; ; ; ; 0.54 W/m2K for 160, 170, 180 and 190 °C of oil temperature, respectively. Higher oil temperature for deep fat frying increased values of heat transfer coefficient. A steady state method was used to determined thermal conductivity of "Kroštula" dough in temperature range of 40 to 70&plusmn ; ; ; ; ; ; 1 °C. The thermal conductivity first increased with temperature and than after reaching maximum values decreased. The maximum value 0.5985&plusmn ; ; ; ; ; ; 0.0196 W/mK was determined at 47.5 °C. The minimal value 0.4723&plusmn ; ; ; ; ; ; 0.0192 W/mK was determined at 65 °C.

Izvorni jezik
Engleski

Znanstvena područja
Prehrambena tehnologija

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