Effect of processing temperature on dynamic rheological properties and color degradation kinetics of bael fruit pulp

A lack of knowledge about the dynamic rheological properties and color degradation of bael fruit pulp gives rise to many problems during thermal processing for the preparation of bael fruit products. In this research, the effects of processing temperature (30-75 °C) on dynamic rheology and color degradation kinetics of bael fruit pulp were studied and analyzed.

Bael fruit pulp showed more elastic behavior than viscous behavior by analyzing the storage modulus, loss modulus and phase angle over oscillatory frequency range 0.06-300 rad s^-1 . The dynamic rheological study classified the bael fruit pulp as a weak gel (G' > G″). The values of first-order degradation rate constant (k) were determined to be 0.07, 0.011, 0.018 and 0.023 for 30, 45, 60 and 75 °C, respectively. The first-order color degradation kinetics of bael fruit pulp has given a higher value of activation energy (E_a = 23.83 kJ mol^-1 ) with coefficient of determination (R² ) of 0.99, which indicated a higher sensitivity for treatment temperature and time during processing.

The results obtained would allow simplification of processes for easier formulation of quality products from bael fruit pulp. This study has the potential to increase the processing ability of bael fruit, which will encourage a greater production of bael fruits. © 2020 Society of Chemical Industry.