Abstract:
Research was initiated to find a secondary bleach to remove
brown discoloration on sulfur dioxide brined sweet cherries. In addition,
studies were carried out to determine the effects on texture
of not only the secondary bleaches, but also the primary bleach (sulfur
dioxide).
Three bleaches were found to remove the pigments in question
leaving a snow white fruit at the end of the process, These were
sodium and calcium hypochlorite and sodium chlorite.
The study of the brining effects on the original fruit showed
that most firming occurred within the first four and one half weeks.
These constituents affecting firmness, the pectins and cellulose, did
not appreciably change during the curing process. Only the uptake of
calcium into the pectin was noted after the first few weeks.
Analyses showed that secondary bleaching with the hypochlorites
was too destructive to the cherry tissue. Sodium hypochlorite
was extremely harsh, as it destroyed up to one half of the original
cellulose and lowered the calcium level in the pectin. Calcium hypochlorite
was found to be less severe, although some destruction did
occur. Another problem encountered with the hypochlorites was the
difficulty in controlling the reaction unless constant care was maintained.
No change in the constituents affecting texture was found with
sodium chlorite bleaching agent. Texture was still firm and although
the process took longer than the hypochlorite process, very little
attention was needed. Sodium chlorite was determined to be the best
bleaching agent for secondarily bleaching brined cherries. No off-flavors
developed when the fruit was processed into maraschino
cherries.
