Response surface methodology in rheological characterization of Papaya puree

The individual and interactive effects of temperature (5-65degreesC), total soluble solids (TSS) (10-30degreesBrix), pH (3-7), and g-amylase concentration [(0.25-1.25)kg 100 kg(-1) puree] on rheological characteristics of papaya (Carcia papaya L.) puree were studied by the application of the response surface methodology (RSM) using a computer controlled rotational viscometer. Papaya puree exhibited pseudoplasticity with yield stress and flow following Herschel-Bulkley model. A quadratic model developed for rheological parameters met all the criteria of good fit and provided information for characterizing the effect of different variables. It was observed that temperature, TSS and pH individually and in combination affected consistency index (P < 0.05) while flow behavior index was significantly influenced by all four factors (P < 0.05). The temperature and enzyme concentration considerably affected apparent viscosity.