Burn Defect and Phenol Prediction for Flavoured Californian-Style Black Olives Using Digital Sensors

Abstract

Californian-style black olives can undergo different chemical changes during the sterilization process that can affect their sensory and phenol characteristics. Thus, these olives were stuffed with flavoured hydrocolloids and submitted to different thermal sterilization treatments to assess sensory categories. The triangular test indicated that the panellists were able to discriminate between samples from different categories according to their aromas with more than 85% success. The results indicated that the negative aroma detected by tasters was related to burn defects. The highest level of defects was found in standard olives, while the lowest was identified in the extra category. Furthermore, olives submitted to the lowest thermal sterilization treatment (extra) presented significantly higher phenol profile content, such as for hydroxytyrosol, tyrosol, oleuropein and procyanidin B1. The electronic nose (E-nose) discriminated between samples from different categories according to the specific aroma (PC1 = 82.1% and PC2 = 15.1%). The PLS-DA classified the samples with 90.9% accuracy. Furthermore, the volatile organic compounds responsible for this discrimination were creosol, copaene, benzaldehyde and diallyl disulphide. Finally, the models established by the PLS analysis indicated that the E-nose could predict olives according to their aroma and total phenol profile (RCV2 values were 0.89 and 0.92, respectively). Thus, this device could be used at the industrial level to discriminate between olives with different sensory aromas to determine those with the highest quality.

Detection of Aroma Profile in Spanish Rice Paella during Socarrat Formation by Electronic Nose and Sensory Panel

“…Furthermore, Hu et al [29] showed that aldehydes such as hexanal, octanal, nonanal, etc., probably contribute the most to the overall flavor because of the low odor threshold. Hydrocarbon compounds, which were the second largest group, are also related to positive aromas [30], and their content decreased with treatment time (from 22.4 to 2.9% for WR and from 5.4 to 0.5% for P). In both cases of aldehyde and hydrocarbon compounds, higher contents were obtained for WR compared to P. This is due to the influence of other aromas from the ingredients added in P, such as vegetables, garlic and shellfish related to sulfurous compounds [31], which were not found in WR.…”

“…Diallyl disulfide and diallyl sulfide, which are associated with spicy and green aromas [31], respectively, increased slightly with thermal treatment, probably due to the cooking of the ingredients. Furan and furanone compounds, which are related to roasted, bitter and caramel aromas [30][31][32]38], were found at the end of the processing time in WR and P. Furfural was the one that was found with the highest intensity in WR, which coincides with the previous analysis of 5-methyl-2-furancarboxaldehyde and the sensory analysis results that found a greater burnt aroma at the end of the processing time in WR compared to P. In general, these furans and furanone compounds can be formed by the Maillard reaction by heating carbohydrates [29].…”

Recent Advances and Future Perspectives in the E-Nose Technologies Addressed to the Wine Industry

“…Indeed, the application of these types of sensors is now widespread, spanning various fields, from biomedicine [7][8][9][10] and environmental science [11][12][13] to industrial materials production [14,15] and the food industry [16][17][18][19][20][21].…”