scholarly journals The Use of Electronic Nose as Alternative Non-Destructive Technique to Discriminate Flavored and Unflavored Olive Oils

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2886
Author(s):  
Nuno Rodrigues ◽  
Kevin Silva ◽  
Ana C. A. Veloso ◽  
José Alberto Pereira ◽  
António M. Peres

Cv. Arbequina extra virgin olive oils (EVOO) were flavored with cinnamon, garlic, and rosemary and characterized. Although flavoring significantly affected the physicochemical quality parameters, all oils fulfilled the legal thresholds for EVOO classification. Flavoring increased (20 to 40%) the total phenolic contents, whereas oxidative stability was dependent on the flavoring agent (a slight increase for rosemary and a decrease for cinnamon and garlic). Flavoring also had a significant impact on the sensory profiles. Unflavored oils, cinnamon, and garlic flavored oils had a fruity-ripe sensation while rosemary flavored oils were fruity-green oils. Fruit-related sensations, perceived in unflavored oils, disappeared with flavoring. Flavoring decreased the sweetness, enhanced the bitterness, and did not influence the pungency of the oils. According to the EU regulations, flavored oils cannot be commercialized as EVOO. Thus, to guarantee the legal labelling requirement and to meet the expectations of the market-specific consumers for differentiated olive oils, a lab-made electronic nose was applied. The device successfully discriminated unflavored from flavored oils and identified the type of flavoring agent (90 ± 10% of correct classifications for the repeated K-fold cross-validation method). Thus, the electronic nose could be used as a practical non-destructive preliminary classification tool for recognizing olive oils’ flavoring practice.

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 369
Author(s):  
Giacomo Squeo ◽  
Roccangelo Silletti ◽  
Giacomo Mangini ◽  
Carmine Summo ◽  
Francesco Caponio

In this study, the drupes and virgin olive oils extracted from the Oliva Rossa landrace are characterized. Oliva Rossa is an old landrace part of the autochthonous Apulian olive germplasm for which only few data have been reported till now. During the study, the maturity patterns of the drupes had been followed. Four samplings per year were planned, one every 14 days starting from the middle of October. The pigmentation index, the oil content and the total phenolic content of the drupes were measured. Simultaneously, virgin olive oils were extracted at the lab scale and analyzed for the fatty acid composition, the basic quality parameters and the content of minor compounds. The pigmentation pattern of the drupes was different among the years and, despite this trend, at the third sampling time the stage of maximum oil accumulation was always over. The extracted virgin olive oils had a medium to high level of oleic acid. With colder temperatures, a higher level of monounsaturated fatty acids, oleic/linoleic ratio and antioxidants was observed. The phenolic profile was dominated by 3,4-DPHEA-EDA and p-HPEA-EDA while the volatile profile by (E)-2-hexenal and 3-ethyl-1,5-octadiene.


2021 ◽  
Vol 33 (1) ◽  
pp. 61-72
Author(s):  
Pierluigi Plastina ◽  
Rosa Tundis ◽  
Chiara La Torre ◽  
Vincenzo Sicari ◽  
Angelo Maria Giuffré ◽  
...  

This study aimed to evaluate the influence of Capsicum baccatum L. Aji Angelo and Bishop crown cultivars to the quality parameters of flavoured olive oils (FOOs) obtained by the addition of both fresh and dried pepper powders (1%) to Dolce di Rossano and Roggianella monovarietal extra virgin olive oils (EVOOs). First, pepper extracts were investigated for their total phenolic, flavonoid, carotenoid content as well as phenolic acids, fatty acid profile, and vitamin C and E content. In order to evaluate the impact of both fresh and dried peppers on the oxidative stability of FOOs, the Rancimat test was applied. 2,2-Azinobis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ?-carotene bleaching (B-CB) and ferric reducing antioxidant power (FRAP) assays were used to investigate the antioxidant potential. Bishop crown dried extracts showed the highest phenolic, carotenoid and vitamin content, whereas Aji Angelo had the highest amount of capsaicinoids. Among EVOOs, Roggianella EVOO showed the highest antioxidant activity as well as the highest induction time (39.6 h). Remarkably, FOO obtained by the addition of Bishop crown dried pepper extract to Roggianella EVOO showed a higher induction time (44.9 h) with respect to the corresponding EVOO.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Rafaela Prata ◽  
José A. Pereira ◽  
Nuno Rodrigues ◽  
Luís G. Dias ◽  
Ana C. A. Veloso ◽  
...  

Olive oil has unique organoleptic attributes and its consumption is associated with nutritional and health benefits, which are mainly related to its rich composition in phenolic and volatile compounds. The use of olive oil in heat-induced cooking leads to deep reduction of phenolic and volatile concentrations and to changes of the sensory profiles. This work confirmed that oven and microwave heating significantly reduced total phenolic contents (P value < 0.0001, one-way ANOVA), more pronounced in the latter, together with a significant reduction of the intensity of fruity, sweet, bitter, pungent, and green attributes (P value < 0.0001, Kruskal-Wallis test), particularly for fruity and green sensations. Besides, bitter, fruity, green, and pungent intensities showed a linear dependency with the total phenolic contents (0.8075≤R-Pearson ≤ 0.9694). Finally, the potentiometric electronic tongue together with linear discriminant analysis-simulated annealing algorithm allowed satisfactory discrimination (sensitivities of 94±4%, for repeated K-fold cross-validation) of olive oils subjected to intense microwave heating (5–10 min, 160–205°C) from those processed under usual cooking conditions (oven heating during 15–60 min or microwave heating during 1.5–3 min, 72–165°C). This could be due to the different responses of the electronic tongue towards olive oils with diverse phenolic and sensory profiles.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 929
Author(s):  
Stefano Farris ◽  
Susanna Buratti ◽  
Simona Benedetti ◽  
Cesare Rovera ◽  
Ernestina Casiraghi ◽  
...  

The performance of two innovative packaging materials was investigated on two Sardinian extra-virgin olive oils (Nera di Gonnos and Bosana). In particular, a transparent plastic film loaded with a UV-blocker (packaging B) and a metallized material (packaging C) were compared each other and to brown-amber glass (packaging A). During accelerated shelf-life tests at 40 and 60 °C, the evolution of quality parameters (i.e., acidity, peroxide value, K270, and phenolic content) was monitored, together with the aromatic fingerprint evaluated by electronic nose. Packaging B resulted in the best-performing material in protecting oil from oxidation, due to its lower oxygen transmission rate (0.1 ± 0.02 cm3/m2 24 h) compared to packaging C (0.23 ± 0.04 cm3/m2 24 h). At the end of storage, phenolic reduction was on average 25% for packaging B and 58% for packaging C, and the aromatic fingerprint was better preserved in packaging B. In addition, other factors such as the sanitary status of the olives at harvesting and the storage temperature were demonstrated to have a significant role in the shelf life of packaged extra-virgin olive oil.


2019 ◽  
Vol 6 (3) ◽  
pp. 190002
Author(s):  
Qi Zhou ◽  
Shaomin Liu ◽  
Ye Liu ◽  
Huanlu Song

Flavour is a special way to discriminate extra virgin olive oils (EVOOs) from other aroma plant oils. In this study, different ratios (5, 10, 15, 20, 30, 50, 70 and 100%) of peanut oil (PO), corn oil (CO) and sunflower seed oil (SO) were discriminated from raw EVOO using flavour fingerprint, electronic nose and multivariate analysis. Fifteen different samples of EVOO were selected to establish the flavour fingerprint based on eight common peaks in solid-phase microextraction–gas chromatography–mass spectrometry corresponding to 4-methyl-2-pentanol, ( E )-2-hexenal, 1-tridecene, hexyl acetate, ( Z )-3-hexenyl acetate, ( E )-2-heptenal, nonanal and α-farnesene. Partial least square discrimination analysis (PLS-DA) was used to differentiate EVOOs and mixed oils containing more than 20% of PO, CO and SO. Furthermore, better discrimination efficiency was observed in PLS-DA than PCA (70% of CO and SO), which was equivalent to the correlation coefficient method of the fingerprint (20% of PO, CO and SO). The electronic nose was able to differentiate oil samples from samples containing 5% mixture. The discrimination method was selected based on the actual requirements of quality control.


Sensors ◽  
2017 ◽  
Vol 17 (11) ◽  
pp. 2642 ◽  
Author(s):  
Ana Garrido-Varo ◽  
María-Teresa Sánchez ◽  
María-José De la Haba ◽  
Irina Torres ◽  
Dolores Pérez-Marín

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Claudia Guillaume ◽  
Leandro Ravetti

Extra virgin olive oil shelf-life could be defined as the length of time under normal storage conditions within which no off-flavours or defects are developed and quality parameters such as peroxide value and specific absorbance are retained within accepted limits for this commercial category. Prediction of shelf-life is a desirable goal in the food industry. Even when extra virgin olive oil shelf-life should be one of the most important quality markers for extra virgin olive oil, it is not recognised as a legal parameter in most regulations and standards around the world. The proposed empirical formula to be evaluated in the present study is based on common quality tests with known and predictable result changes over time and influenced by different aspects of extra virgin olive oil with a meaningful influence over its shelf-life. The basic quality tests considered in the formula are Rancimat® or induction time (IND); 1,2-diacylglycerols (DAGs); pyropheophytin a (PPP); and free fatty acids (FFA). This paper reports research into the actual shelf-life of commercially packaged extra virgin olive oils versus the predicted shelf-life of those oils determined by analysing the expected deterioration curves for the three basic quality tests detailed above. Based on the proposed model, shelf-life is predicted by choosing the lowest predicted shelf-life of any of those three tests.


Author(s):  
G. Squeo, G. Difonzo, Vito. M. Paradiso, C. Summo, A. Pasqualone, F. Caponio

Fatty acid ethyl esters are the newest mandatory quality parameters introduced for extra virgin olive oil classification linked to fermentative processes occurring in low-quality olives. Although it is clear the strong linkage of ethyl esters with sensory fermentative defects there is a lack of knowledge about their relationship with specific volatile compounds. Hence, a study was carried out to evaluate the correlation among extra virgin olive oil quality indices and its respective volatile profile with fatty acid ethyl esters. Thirty-five virgin olive oils were collected from local oily industry and analysed for the fatty acid ethyl esters content, the basic quality parameters, the total phenolic content and the volatile profile. The obtained results showed that the fatty acid ethyl esters were negatively correlated to total phenolic compounds (p<0.05) and trans-2-hexenal content (p<0.001) while positively correlated (p<0.001) to ethyl acetate and ethyl acetate/trans-2-hexenal and ethyl acetate/hexanal ratios. Interestingly, ethanol was not correlated at all with the ethyl esters content in oils.


Sign in / Sign up

Export Citation Format

Share Document