Location: Food Science Research
Project Number: 6070-41000-007-13-N
Project Type: Nonfunded Cooperative Agreement
Start Date: Feb 1, 2012
End Date: Sep 30, 2013
To evaluate a cucumber preservation method that would allow the processing of the preserved fruits without washes prior to packing into final product. The final cover brine formulation should preserve cucumbers for 9 months or more, and equilibrate with the fruits to contain about 1.1% acetic acid, reduced sodium chloride (4% or less), and pH 3.3 or lower.
ARS scientists developed reduced sodium chloride and acetic acid cover brine formulations to effectively preserve cucumbers at pH 3.5 for up to a year in the absence of oxygen. It is the intent of this research to scale up the successful treatments from such laboratory trials to commercial products imported to the United States. Although the presence of oxygen in the commercial packaging is likely to encourage microbial growth and make the preservation more difficult to achieve, treatments containing 1.1% acetic acid, 0.45% calcium chloride, 0- 4% sodium chloride, and combinations of either traditional preservatives such as potassium sorbate and sodium benzoate or natural preservatives, and fumaric acid will be tested. Phosphoric acid will be evaluated as an additional ingredient to achieve a pH of 3.3 or below, as the reduction of acetic acid to 1.1% will not make it possible to reach this target. Preliminary studies will be conducted concomitantly in the U.S. and an international processing facility with the aim of reducing the list of successful treatments, refine the cover brine formulations, and define the acidification needs for the preservation treatments to achieve a pH of 3.3. The evaluation of treatments in the United States would include the monitoring of microbial growth, primarily lactic acid bacteria, yeasts and molds, and enterobacteria, basic chemical analysis for sugars and organic acids, pH, titratable acidity and a single point texture evaluation. The evaluation of treatments from international processing facilities will include the monitoring of the development of pressure and turbidity, and the determination of pH and titration of acidity. Treatments identified as effective during the preliminary stage will be further evaluated in Phase 1 and polished in Phase 2 to develop a close to commercialization formulations. The evaluation of treatments during Phases 1 and 2 will proceed in the same fashion described above for the international preliminary trials.