Volatile Profile of Two-Phase Olive Pomace (Alperujo) by HS-SPME-GC–MS as a Key to Defining Volatile Markers of Sensory Defects Caused by Biological Phenomena in Virgin Olive Oil

Abstract

An olive pomace from the two-phase decanter stored in different conditions was used as a model to simulate the detrimental biological phenomena occurring during olive oil processing and storage. A group of EVOO and defective oils were also analyzed. The volatile fraction was studied with HS-SPME-GC–MS; 127 volatiles were identified (55 of which tentatively identified) and evaluated over time. Seven volatiles were tentatively identified for the first time in olive oil; the role of C6 alcohols in detrimental biological phenomena was highlighted. Suitable volatile markers for defects of microbiological origin were defined, particularly the fusty/muddy sediment. They were then applied to olive oils with different quality categories; one of the markers was able to discriminate among EVOOs and all the defective samples, including the borderline ones. The marker was constituted by the sum of concentrations of 10 esters, 4 alcohols, 1 ketone, and 1 α-hydroxy-ketone but no carboxylic acids.

Geographical origin discrimination of “Ntopia” olive oil cultivar from Ionian islands using volatile compounds analysis and computational statistics

“…1 . The volatile compounds that were identified in the present study are in accordance with previous studies dealing with the cultivar or geographical origin determination of olive oil either from Greece [ 12 , 26 , 28 , 29 ] or other countries [ 16 – 18 , 20 , 22 , 27 , 34 , 38 , 39 ].…”

“…On the contrary, 1,3-bis(1,1-dimethylethyl)benzene was identified in all olive oil samples, recording higher concentration in samples from Zakynthos. This benzene derivative was not reported previously to contribute to the aroma of olive oil of the Koroneiki cultivar from Zakynthos [ 28 ], Picholine marocaine cultivar from Morocco [ 13 ], and Alperujo cultivar from Florence (Italy) [ 39 ], whereas scarce data are available, in general, for this compound in the relevant literature [ 2 , 13 , 22 , 23 , 28 , 39 ]. These phenolic volatiles may give olive oil a bitter and spicy oil flavor [ 2 ].…”

“…Previous studies in the literature dealing with the determination of volatile compounds of olive oil from Morocco (Picholine marocaine cultivar) [ 13 ], Brazil (Arbequina, Arbosana, Picual, Koroneiki, Grapollo, Coratina and Frantoio cultivars) [ 20 ], Greece (Koroneiki cultivar) [ 28 ], and Italy (Leccino cultivar) [ 22 ] did not report the presence of ethanol in the aroma of olive oil samples. However, in the Italian olive cultivar “Alperujo” ethanol was identified in olive oil during the analysis of volatile compounds [ 39 ]. Therefore, ethanol may be proposed as a characteristic volatile compound of olive oil associated with its cultivar, giving thus, some special sensory characteristics to olive oil.…”

“…As far as the volatile profile of olive oil, it is highly correlated with its organoleptic properties, as volatile compounds are responsible for both positive and negative olfactory characteristics [ 38 , 39 ] contributing further to its qualitative characteristics [ 17 , 18 ]. A previous study reported data for olive oil samples of the “Ntopia” cultivar from Zakynthos, Leukada, and Kerkyra concerning the quality indices and physicochemical composition on the basis of acidity (0.25–1.27% of oleic acid), peroxide value (6.87–72.49 meqO 2 /kg), K 232 (1.31–15.95), K 270 (0.10–1.74), ΔΚ (− 0.004 to 1.03) extraction coefficients, chlorophyll and carotenoid contents (0.08–4.46 mg/kg of pheophytin A and 0.87–2.22 mg/kg of lutein, respectively) and fatty acid content (myristic acid 0.01–0.02%; margaric acid 0.01–0.10%; stearic acid 1.83–3.35%; arachidic acid 0.35–0.46%; and eicosenoic acid 0.21–0.31%) [ 30 ].…”

The Difference of Volatile Compounds in Female and Male Buds of Trichosanthes anguina L. Based on HS-SPME-GC-MS and Multivariate Statistical Analysis

“…Carboxen/polydimethylsiloxane (CAR/PDMS) fiber was used for the analysis of volatile compounds from European ciders [ 24 ]. Divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was able to extract more chemical diverse volatile compounds, including ketones, aldehydes, alcohols, terpenoids, and others from Medicago sativa L. (family Leguminosae) compared with PDMS and CAR/PDMS fibers [ 25 ] and to analyze a variety of plants and their oils such as sweet potato, tomato, and olive oils [ 26 , 27 , 28 ]. In this study, DVB/CAR/PDMS fiber was selected due to its better ability to provide a more comprehensive chemical profile of plants and its great extraction effect in the pre-experiment.…”