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Purchase Article

Tech. Q. Master Brew. Assoc. Am., 1996, 33(4), 213-217.

Use of suspension testing in a protocol for evaluating biocidal conveyor lubricants.

Schasteen, E., Mallory, W., McNelis, B. and Pringle, A.

Because of the risk that microorganisms growing on packaging line conveyors may contaminate open beer containers, leading to spoilage, the lubricants applied to the conveyors often incorporate biocidal constituents intended to control the growth of microorganisms. A procedure for testing the effectiveness of these constituents is described. A suspension containing known concentrations of viable cells of two species of beer spoilage bacteria and a wild yeast was added to dilute, normal and concentrated solutions of the lubricants under test (which were taken from a short list drawn up on the basis of an assessment of manufacturers' quality assurance procedures and an evaluation of the lubricants' physical properties), with or without the addition of beer, and the surviving cells were counted after 1, 5 and 60 minutes. The lubricants were further tested on filling lines, where lubricant samples, swabs which had been wiped over conveyor surfaces, and air samples from the vicinity of the conveyors were collected for microbiological analysis to determine the practical antimicrobial effectiveness of the lubricants. The best results were obtained from a synthetic lubricant to which a quaternary ammonium disinfectant had been added.
Keywords : comparative test contamination conveyor disinfectant hygiene lubricant performance properties