اثر فشار و دمای تغلیظ بر برخی خصوصیات کیفی آب هندوانه

Watermelon juice was concentrated by heating at three different temperature-pressure matches (at atmospheric, 38.5 and 7.3 kPa) and 100, 75 and 40°c. The effect of operational pressure-temperature on evaporation rate, pH, viscosity, density and lycopene content of watermelon juice versus time of concentration was evaluated. The result was shown that the higher vacuum degree lead to higher evaporation rate and better preservation of lycopene content as well. The pH of samples didn't change during heating concentration. It was shown there is a linear correlation between density and concentration degree of samples. Also viscosity of samples is independent of operational pressure and it is only depend on concentration degree.