Potential of high isostatic pressure and pulsed electric fields to improve mass transport in pea tissue

• High pressure, pulsed electric fields and heat affected the cell walls in pea tissue.
• Warm air drying and rehydration at ambient temperature could be improved by all treatments.
• Treatments led to an enhanced removal of flatulence causing oligosaccharides while preserving most of the extractable protein.
• Pulsed electric fields can serve as a tool for a selective extraction of small cell compounds without affecting protein quality.
• High isostatic pressure can improve mass transport from whole peas and contemporaneously modify their functional properties.

The aim of this study was to investigate and evaluate the potential of high isostatic pressure (HP) and pulsed electric fields (PEF) for implementation in innovative legume processing concepts. Whole peas were subjected to HP (400 MPa, 40 °C, 10 min) and PEF (5 kV cm− 1, 125 kJ kg −1) treatments. The impact on the pea tissue was assessed by means of microscopic changes, release of protein and oligosaccharides during treatment and rate of subsequent drying and rehydration steps. HP and PEF resulted in altered cell wall structures and improved mass transport in comparison to the control samples (20 °C, 10 min). Effects on the extent of diffusion depended on the molecular size of the cell compounds. More than 10% of raffinose equivalent sugars were removed during treatments while preserving more than 99.9% of nutritionally valuable protein. Hence, both emerging technologies may be implemented in pea processing for a targeted reduction of flatulence causing oligosaccharides. The drying and rehydration rates of whole peas were increased to a higher extent by HP and PEF than by conventional thermal treatments (80 °C, 10 min). These innovative pre-treatments may therefore be applied to enhance the efficiency of industrial mass transfer processes or to decrease the preparation time of meals with whole dried peas and thus increase the flexibility for the consumer.