Abstract

The impact of temperature on the functionality of fruits purees is critical. Hence the objective of this research is to investigate the effect of temperature on the rheological properties of three Li, SW, and TT of Jujube varieties. The raw Jujubes fruits were peeled, pureed, and pasteurized. The samples were subjected to rheological tests using a controlled shear stress-strain rheometer at 5, 25, and 50°C. The results revealed that the Jujube purees exhibit an elastic behavior with G' > G". Except for the Li as the frequency increases beyond 1 Hz the purees losses its structural integrity, hence transformed into a viscous fluid as shown by the crossover point at 10 Hz for SW and 4 Hz for TT. The crossover occurs when the full elastic structure is broken and the puree becomes more viscous in the region where G” > G’. The modulus of each variety significantly (p < 0.05) varied at different temperatures. The steady shear viscometry (0.1 to 1000 s-1), generally showed a more pronounced pseudo-plastic (n < 1) behavior and the presence of yield stresses. Herschel-Bulkley model was found to fit adequately (R2 ≥ 0.90) over the entire shear rate range.