Impact of pulsed electric fields, high hydrostatic pressure, and thermal pasteurization on selected characteristics of Opuntia dillenii cactus juice

- 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.

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 103 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.