Effects of oxygen and turmeric on the formation of oxidative aldehydes in fresh-pack dill pickles.

Hexanal, pentanal, and heptanal were found to be normal components of commercially processed, fresh-pack dill pickles. Hexanal and pentanal were present at concentrations severalfold higher than their odor detection thresholds. These aldehydes were also found in pickles that were packed in the laboratory under anaerobic conditions. Injection of oxygen into pickles prepared in anaerobic conditions resulted in the production of increasing the amounts of hexanal, heptanal, and pentanal. Hexanal, pentanal, (E)-2-hexenal, and heptanal levels were negatively correlated with the addition of turmeric in dill pickles with oxygen injected into the jar, indicating that the curcumin present in turmeric is an effective antioxidant in this product. At commercial coloring levels (250 mg/L), turmeric addition maintained aldehyde levels near the concentrations found in commercial fresh-pack pickles packaged in glass containers when oxygen was added in amounts comparable to that which would enter a plastic container during a 1-year storage period. Therefore, the addition of turmeric appears to be an effective approach to minimize the formation of oxidative off-flavors in pasteurized dill pickles that may result from the oxygen permeability of plastic containers.