Search for spoilage markers of Alicyclobacillus species

摘要

This study analysed the physico-chemical characteristics of ten strains of Alicyclobacillus, other than Aiicyclobacillus acidoterrestris, isolated from food products, in particular tomato derivatives. Their ability to spoil tomato, pear and apple juice was checked. Since the strains under examination did not produce guaiacol in vitro but caused the spoilage of juices following the development of off-odours, we tried to identify the metabolites produced by means of mass gas chromatography. The tests carried out revealed a change in the aroma profile of the product: the growth of micro-organisms was generally accompanied by the development of sulphurated aromatic substances, especially dimethyl sulphides and 2- methyl tetrahydrothiophene-3-one. However, since differences were found between aromatic profiles of the various strains in the different substrates, it was not possible to attribute the off flavour to a single metabolite.