Pickling Cucumber Improvement Committee Meeting Abstract
Department of Food Science, North Carolina State University
One of the reasons for the development of the bag-in-box project is to reduce/eliminate pickle disposal problems caused by excess salt removed from conventionally fermented pickles. In addition, it is desired that the brine from the low-salt fermentation process be reusable. This will require that microbial cells and other insolubles from the brine be removed by a separation process.
We have used a crossflow filtration method in this project because of versatility and cost. The design and optimization of a crossflow filtration system for the removal of insolubles and cells from pickle fermentation brine will entail carrying out studies on the effect of process and material properties on the efficiency of the process. Specifically, we investigated the effect of cell concentration, flow rate, filter pore size and transmembrane pressure on filtration rate, and on the quality of the filtered brine. Results obtained showed that:
(a) Crossflow filtration with filter pore size of 0.2 mm or lower can be effectively used to removal microbial cells and insolubles from brine obtained from the bag-in-box project. The quality of the brine was not affected by the filtration process.(b) The rate at which filtered brine was obtained significantly increased with increase in pressure across the filter and with feed velocity. Within the limits of the cell concentration found in pickle fermentation, rate of brine filtration was not significantly influenced by cell concentration.
(c) Based on the studies carried out and the limits of the pilot-scale cross-flow filtration system used, we recommend that brine filtration should be carried out using the following operating conditions: transmembrane pressure of 15 psi (103.42 kPa), feed flow rate of 3.1 gpm (11.63 L/min), and filter pore size of 0.2 mm. This combination will yield about 3.5 gallons per square feet per hour (140 liters per square meter per hour) of filtered brine.
For further information, contact:
- Dr. O. O. Fasina
- USDA-ARS, Department of Food Science
- North Carolina State University, Raleigh, NC 27695-7624
- Telephone: 919-515-2979; Fax: 919-856-4361
- E-mail: email@example.com