The correlation of redox potential and some chemical parameters in spinach puree during processing and frozen storage

The aim of this work was to study the changes of the principal compounds in spinach during processing into puree and frozen storage and to correlate these with the changes of redox potential (rH) depending on technological parameters and storage conditions (time and temperature). For that purpose two hybride varieties of spinach, Martina and Taurus RZ, were used. A good correlation was found among the changes of rH and the levels of nitrates, oxalates and total chlorophylls as well as peroxidase activity in spinach during processing into puree. The rH significantly diminished during blanching process and reached the lowest value during puree preparation. The rH was also found to be a good indicator of variation in the content of total chlorophylls in spinach puree during frozen storage.