Lactobacillus pentosus is the dominant species in spoilt packaged Aloreña de Málaga

The present study focused on investigating a peculiar spoilage of traditional Aloreña de Málaga table olives characterized by the formation of whitish and soft regions on the olive surface. To determine its causes, the main microbiological and physicochemical changes in 50 commercial packages were monitored until the alteration in appearance (63 days). Colour and firmness of fruits deteriorated progressively in the packaged olives during storage. Sugar in brines (7.5 g/L) remained stable during the first month and then decreased gradually (5.0 g/L) while, in parallel, the lactic acid bacteria population and titratable acidity increased. After two months of storage, evidence of spoilage was noticed, coinciding with the maximal lactic acid bacteria populations in fruit (>6.5 log10 CFU/g). The spoilage affected ¿25% of the fruits within packages. The microbial species detected in the product after packaging were Enterobacter gergoviae and Lactobacillus plantarum among bacteria, and Candida tropicalis, Candida parapsilosis, and Lodderomyces elongisporus among the yeasts while Lactobacillus pentosus was the dominant species in the spoilt packages. A specific biotype of L. pentosus was only detected in the damaged fruits. Further studies will be made to confirm the association between the spoilage and the presence of this L. pentosus biotype.The research leading to these results has received funding from Junta de Andalucía Government through the PrediAlo project (AGR-7755: www.predialo.science.com.es). FNAL wishes to express thanks to the Spanish government for his RyC postdoctoral research contract while VRG would like to thank ceiA3, Spanish Government, Bank of Santander, IG-CSIC and ‘Aloreña de Málaga’ Olive Manufacturing Association for her pre-doctoral fellowship.Peer Reviewe