Crossflow filtration of brine from cucumber fermentation

Due to environmental concerns, pickle companies are considering ways of reclaiming the brine obtained from cucumber fermentation. The removal of microbial cells is crucial in use of the brine in finished pickle products. The effects of transmembrane pressure (41 to 166 kPa), feed flow rate (7.8 to 15.5 L/min), pore size (500, 000 NWCO and 0.2 mum), and cell concentration (optical density of 0.171 to 1.170 at 640 nm) on permeate flux during the crossflow filtration of brine obtained from bulk fermentation of cucumber were studied. Results indicate that the microfiltration membranes exhibited a large flux decline during the first 15 min of operation when challenged with the fermentation brine. The net decline in permeate flux increased with transmembrane pressure, flow velocity, pore size, and cell concentration. Filtration through filter pore size of 0.2 mum or smaller effectively removed the microbial cells present in the brine. Only the transmembrane pressure significantly affected the resistance of the cake formed at the filter surface. From the results obtained from the study, it is possible to use microfiltration to filter sediments and microbial cells from brine obtained from cucumber fermentation.