Sensory Defects of Virgin Olive Oil from a Microbiological Perspective

Virgin olive oil is the juice from the olive drupe, a produce that usually features high 6 quality. However, virgin olive oils produced in different regions of the world suffer from 7 defects, most of them of sensory nature. The largest amount of olive oil in which some 8 organoleptic defect is present matches to the Virgin Olive Oil (VOO) class. The causes 9 leading to sensory defects in virgin olive oil, on the different steps of the elaboration, are 10 not well-known sometimes. Important is to note that current legislation allow the 11 classification with sensory defects as VOO and Lampante Olive Oil (LOO). Volatile 12 compounds are important in the sensory perception of the olive oils, for both the positive 13 attributes and the defects. Knowledge on the biogenesis of the volatile compounds involved 14 in the virgin olive oil defects and in its sensory characterisation, is still scarce. There are 15 different causes of defects, depending on the physical, chemical or microbial degradation 16 affecting the product. These join to the positive attributes, leading to an infinite diversity of 17 sensory 'fingerprints'. The microbes cause the most of the defects sensory analysed in olive 18 oils. Despite some interesting studies reported on the biogenesis of the compounds 19 responsible of such defects, microbiological research within the olive oil production, 20 including post-harvest life of olives, is scarce. We should highlight there is a long way to 21 avoid the generation of sensory defects in olive oils within the production process itself and 22 storage. This paper tries to identify significant shortfalls on the knowledge of the causes 23 and circumstances for inducting sensory defects in olive oils, and defining the major 24 aspects which are sufficiently known. 25