The effect of green tea extract on some qualitative and rheological properties of Rosette

In this research the effect of green tea extract on some qualitative and rheological properties of rosette was studied. Green tea extract with percentages of 0.5, 1 and 1.5 wet basis were used. Rosette dough rheological behavior measured by rotational viscometer at 20, 35 and 50 ° C and speeds10-200 rpm. The effect of temperature on the viscosity and stability of rosette was evaluated using the Arrhenius equation and then activation energy was calculated. The results of this research showed that with increasing temperature, viscosity significantly decreased. Mathematical calculations of finding in basis of Mitchka method showed that the rosette dough was non-Newtonian fluid and the shear thinning. Then the rosette dough was fried for two minutes at 150 ° C. Then oxidative stability index, peroxide and acid index were measured for samples. Results showed using green tea extract caused reduce the peroxide value, acid value and increase oxidative stability index. Use of green tea extract had postponed oil hydrolysis rate and increase the acid value.