Effects of high-voltage electric field treatment on the water activity of bread

Treating bread dough bq a high-voltage electric field (HVEF) during the first fermentation enabled the bread dough to retain water in the gluten fibers, The microstructure of the gluten fibers was still visible even with an HVEF treatment at 50 kV for 20 min, but could no longer be observed when the gluten was treated for more than 30 min, The crumb temperature of the HVEF treated bread during baking began to rise a few minutes sooner than that of the untreated bread, but the maximum temperature reached was the same in both cases: 99 degrees C, The fact that the water activity of the HVEF-treated bread was 0.987 +/- 0.0056, being higher than that of the untreated bread by 0.011, is in good agreement with the growing tests of Rhizopus nigricans. Furthermore, a distinct decrease in the water loss of the baked gluten was observed after the HVEF treatment. These results suggest that the HVEF treatment increased the ability of the gluten fibers, rather than the starch granules, to absorb and retain water; the state of the remaining water is considered to have become immobile, so that migration of moisture to the starch granules in the bread could be minimized.