Impact of pulsed electric fields, high hydrostatic pressure, and thermal pasteurization on selected characteristics of Opuntia dillenii cactus juice. (June 2017) - Moussa-Ayoub, Tamer E.
Abstract: Besides its bioactivity, Opuntia dillenii cactus juice exhibits desirable physicochemical properties. In the present study, impact of innovative pasteurization techniques – pulsed electric fields (PEF) and high hydrostatic pressure (HHP) – on the microbial inactivation, selected physicochemical properties and rheological characteristics, ascorbic acid, flavonols, betacyanins, and the antioxidant activity was evaluated in comparison to the non-pasteurized fresh juice. Results showed that PEF and HHP, as well as thermal pasteurization (TP), reduced the microbial populations found in juice from 10 3 to less than 10 cfu/mL. The non-Newtonian pseudoplastic flow behaviour of juice was maintained by all three methods. PEF and HHP resulted in a better retention of ascorbic acid, while TP reduced 22% of the ascorbic acid content. In contrast, TP caused a slight transformation of isorhamnetin glycosides. PEF and HHP maintained antioxidant activity of juice comparatively better than TP. Highlights: Opuntia dillenii juice possesses high bioactivity and promising characteristics. O. dillenii juice is a viscous non-Newtonian pseudoplastic fluid. HHP, PEF, and thermal pasteurization achieved a similar microbial inactivation. HHP and PEF preserved the physicochemical properties of the fresh juice. HHP and PEF were effective in preserving bioactive compounds such as ascorbic acid.