Osmotic dehydration of carrot tissue enhanced by pulsed electric field, salt and centrifugal force

Mass Transport Improvement by PEF - Applications in the Area of Extraction and Distillation

“…The PEF induced enhanced mass transfer depends on the electric field strength and the applied number of pulses (Rastogi et al, 1999). The same reduction in OD was reported (Rastogi et al, 1999;Amami et al, 2007a;Amami et al, 2007b) for the treatment of apple tissue (Amami et al, 2006).…”

“…Amami et al (Amami et al, 2007a;Amami et al, 2007b) treated the sliced carrots with an electric field strength of 0,6 kV/cm and a specific energy of 19 kJ/kg as well as a pulse duration of 100 µs. After the PEF treatment different osmotic dehydration trials were performed to evaluate the influence of salt and sucrose concentration as well as the additional effect of a centrifugal instead of a static osmotic dehydration process.…”

“…Table 1. Water loss of untreated and PEF treated (0,6 kV/cm, 19 kJ/kg) carrots slices using different salt concentrations for the osmotic solution in a OD process after 4 h (summarized from (Amami et al, 2007b)) By increasing the salt concentration a higher water loss can be obtained and the water loss can be improved even more by using PEF as a pre-treatment. A higher salt concentration leads to a higher diffusion gradient and combining a higher salt concentration with a PEF process, which induces an improved mass transfer, leads to a better diffusion with regard to the dehydration process.…”

Osmotic dehydration of yellow melon using red grape juice concentrate

“…With the ripening, the melon gets softer, the cell wall gradually collapses, the adhesion wall-wall is decreased and the average blade begins to dissolve (Nishiyama et al, 2007). All these changes alter the permeability of the cell membrane and hence its osmotic dehydration rate (Amami et al, 2007;Panarese et al, 2012;Rastogi et al, 2002). This variation in the permeability of the cell membrane of the melon should has been low since no relevant changes were observed in the rate of the DD.…”

“…The efficiency of the DD process can be affected by: nature, size and shape of the biological material; nature, type and concentration of the osmotic agent; and process parameter (temperature, time, work pressure, agitation); osmotic solution to sample ratio; and fruit pre-treatment (Amami et al, 2007;Chavan & Amarowicz, 2012;Nowacka et al, 2014;Yadav & Singh, 2014). The reduction of pressure during osmotic dehydration increases the rate of the process and facilitates the penetration of the osmotic solution solutes into the fruit matrix.…”