Influência da temperatura no comportamento reológico da polpa de jabuticaba

Abstract

The steady state and dynamic rheological behavior of jaboticaba pulp was studied at different temperatures (5, 25, 45, 65 and 85°C). Flow curves were obtained from 0 to 300 s-1 and the data were fitted to different models. The Herschel-Bulkley model showed the best fit (R2 > 0.98) to the experimental data. Increasing the temperature caused a decrease in the consistency index (k) and a slight increase in the flow index (n). Oscillatory rheological measurements were taken in the viscoelastic region to obtain mechanical spectra. The storage modulus (G′) of samples stored at 5°C was much higher than that recorded at other temperatures, indicating more intense particle interactions at this temperature, which contributed to strengthen the elastic network. At 45°C, the jaboticaba pulp showed a distinct behavior, possibly indicating the beginning of gelation of the pulp's natural pectin.