Purpose: The objective of this study was to identify and quantify the production of guaiacol, and other potential compounds associated with AA spoilage in orange and apple juice (11ºBrix).
Methods: Initially, we evaluated 497 strains of A. acidoterrestris isolated from fruit juices and tomato-based products collected in Argentina and Brazil. The ability of the isolates to produce guaiacol was assessed through the use of an enzymatic method. Positive strains for guaiacol production were then individually inoculated at level of 102-3CFU ̸ ml in 10 ml of orange and apple juices, following storage at 45°C for 5 days. The techniques of micro-solid phase extraction by headspace (HS-SPME) and gas-chromatography with mass spectrometry (GC-MS) were used to identity and quantify volatile compounds produced by AA strains.
Results: From the 497 strains screened for guaiacol production, a total of 165 were confirmed by the enzymatic method to be able to produce guaiacol. Therefore, these strains were confirmed to be potentially deteriorigenic. CG-MS analysis was performed to further characterize and quantify the volatile compounds that can be associated with orange and apple juice spoilage by AA. A classification of AA strains in terms of their spoilage potential will be presented as well as the discrimination of volatile compounds produced by these strains.
Significance: This work will allow gaining insights on the incidence and spoilage potential of AA strains isolated from a variety of fruit-based products marketed in Argentina and Brazil.