Adjustment of milling, mash electroporation and pressing for the development of a PEF assisted juice production in industrial scale

Application of pulsed electric field in the production of juice and extraction of bioactive compounds from blueberry fruits and their by-products

“…On the other hand, a positive impact of PEF on extraction of polyphenols was also observed in juices obtained after PEF treatment of grapes (Donsi et al 2010b;Grimi et al 2009) and apple mash (Grimi et al 2011;Jaeger et al 2012;Schilling et al 2008). For example, the PEF pre-treatment of crushed grapes during wine-making induced a significantly higher release of polyphenols (+20 %) and anthocyanins (+ 75 %) than in the untreated samples (Donsi et al 2010b).…”

“…For example, the PEF pre-treatment of crushed grapes during wine-making induced a significantly higher release of polyphenols (+20 %) and anthocyanins (+ 75 %) than in the untreated samples (Donsi et al 2010b). TP content was also found to increase with the application of PEF treatment before the pressing of apple mash in the range from 198 to 500 mg/L depending on the mash size, PEF treatment intensity and de-juicing system (Jaeger et al 2012). …”

“…This indicates that the cell disintegration level (Z p = 0.70) achieved with the lower PEF treatment intensity resulted in the most favourable de-juicing properties of blueberries. According to Jaeger et al (2012), high intensity treatment may cause softening of the plant tissues to an extent that is unfavourable for de-juicing i.e., causes the compaction and closing of the capillaries in the press cake. The application of PEF in combination with mechanical juice expression by pressing was demonstrated to be effective for improving juice yield from different plant-based materials (Donsi et al 2010a).…”

“…The application of PEF in combination with mechanical juice expression by pressing was demonstrated to be effective for improving juice yield from different plant-based materials (Donsi et al 2010a). The reported improvement of the juice yields varies widely, most likely due to different intrinsic characteristics of the tissues and process conditions employed in different studies (degree of particles fragmentation, PEF parameters and compression pressure) (Jaeger et al 2012). It has been reported that PEF pre-treatment of grapes accelerated the juice expression and increased juice yield by approximately 24 % for Muscadelle, Sauvignon and Semillon varieties (Praporscic et al 2007) and by 8 % for the Chardonnay variety (Grimi et al 2009).…”

“…Due to its non-thermal impact on foodstuffs, PEF treatment may exert a selective permeability of the membranes (tonoplast and plasma membrane) whereas the cell wall remains intact, which improves the purity and the yield of the extracts. It has been shown that in combination with mechanical pressing, PEF treatment is likely to increase the yield and quality of the juice extracted from fruits and vegetables such as apples, grapes, and carrots (Grimi et al 2011;Jaeger et al 2012;Praporscic et al 2007). Furthermore, PEF also helps increase the extraction rates of colorants (anthocyainins, carotenoids, betanines, etc.)…”