The impact of pulsed electric fields and ultrasound on water distribution and loss in mushrooms stalks

- Microstructural changes in mushroom stalks were studied.
- PEF and US were evaluated when applied at both low and high temperatures.
- A good correlation between disintegration index and water distribution was recorded.
- PEF was more effective than US in extracting intracellular water.
- A selective release of inner compounds was noticed with the different technologies.

Pulsed electric fields (PEF) and ultrasound (US) are promising innovative technologies with the potential to increase mass transfer when combined with further processes which in turn can provide potential benefits in the recovery of valuable compounds from food by-products. To provide evidence of the mechanism of mass transfer enhancement, the present study assessed the impact of PEF and US treatments, applied individually and in combination, at low and high temperatures, on the tissue microstructure of mushroom stalks. Different indices such as quantitative water redistribution, water loss and qualitative release of compounds were evaluated. The combination of these physical methods demonstrated that PEF redistributed a greater proportion of intracellular water into extracellular spaces than US. However, the application of high temperature treatments alone showed an even greater proportion of intracellular water migration compared to PEF. When PEF was combined with US at low temperatures the difference was not significant.