## 4 Conclusions  
This study shows the complexity of predicting the shelf-life of VOO overall when the sensory quality is considered as a relevant criterion in addition to physico-chemical parameters. Thus, the sensory defects that can appear during storage can be detected by consumers with a resulting refusal of the product. On the other hand, this change of quality can be marked enough to result in a downgrading of category (from \"extra virgin olive oil\" to \"virgin olive oil\" and even to \"lampante olive oil\"), with the consequent non-conformity result when the oil category is checked by a panel test. This change of quality is explained by the changes in the concentrations of volatile compounds during storage. Thus, while the compounds contributing with positive sensory attributes (C6 and C5 compounds) reduce their concentration, those compounds coming from oxidation (mainly aldehydes and acids) increase their concentration. The panel tests revealed that the reduction of the compounds contributing to positive notes can result in the detection of fermentative sensory defects (e.g., winey-vinegary) that the oil already contained but they were masked by the intense green aroma. The oil stability studied by [PERSON] at the beginning of the storage produced results that disagreed with the actual sensory changes detected in the storage experiment. The stability studied by mesh-cell FTIR revealed that the band assigned to aldehydes permitted to establish a stability order of the oils that was closer to the order of stability according to the sensory changes (determined by panel test). This result underscores the importance of considering light and moderate temperatures when studying the oil stability in order to avoid unexpected quality-category downgrading. The results also showed that the changes on sensory characteristics and volatile profile followed a different trend depending on the studied oil and there is not a uniform change rate that could be stablished for all the oils.  
The following are available online: Figure S1. PCA score plots of cases (monthly collected samples) calculated using the volatile compounds which showed significant changes (p\(<\)0.05) and RSD\(\%\)\(>\)50% during the storage time. The numbers indicate the month when the sample was collected and analyzed in the storage experiment. Table S1. Concentration of volatile compounds (mg/kg) in VOO1 during the storage experiment. Table S2. Concentration of volatile compounds (mg/kg) in VOO2 during the storage experiment. Table S3. Concentration of volatile compounds (mg/kg) in VOO3 during the storage experiment. Table S4. Concentration of volatile compounds (mg/kg) in VOO4 during the storage experiment. Table S5. Concentration of the chemical series of the volatile compounds identified in the oils (mg/kg) in two different moments (before and after the storage experiment).  
Conceptualization, D.L.G.-G. and N.T.; data curation, A.L.-P. and R.A.-R.; investigation, D.L.G.-G., M.T.M., R.A.-R., N.T. and A.L.-P.; methodology, D.L.G.-G., M.T.M., R.A.-R., N.T. and A.L.-P.; project administration, D.L.G.-G.; resources, A.L.-P. and M.T.M; supervision, D.L.G.-G., M.T.M., R.A.-R., N.T. and A.L.-P.; writing--original draft, A.L.-P. and D.L.G.-G.; writing--review & editing, N.T., R.A.-R. and M.T.M. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Spanish Research State Agency (research projects AGL2015-69320-R and RTI2018-101546-B-C21).  
The authors would like to thank the collaboration of the accredited panel of the Instituto de la Grasa (CSIC), in particular to Mr. [PERSON] for the sensory assessment carried out of this study and the fruitful discussion about the sensory changes of the oils.  
The authors declare no conflict of interest.