CORA - An automated method for the evaluation and comparison of the microbial activity in cork and cork stoppers

Abstract

A new method for quantitative evaluation of the microbial load of cork and cork stoppers, coded CORA (Cork Activity Assay) is described. It is based on measurement by gas chromatography of dimethylsulfide (DMS) evolving from the reduction of dimethylsulfoxide (DMSO) by microbial activity. The method is accurate, gives results within 48 h and can be automated. Test results for various types of cork, sampled before, during and after the manufacturing process of bottle closures, are provided. The use of CORA as a tool for the development of better production processes to limit cork infection by micro-organisms and for advanced microbiological quality control is discussed.