Changes in antioxidant concentration of virgin olive oil during thermal oxidation

Nissiotis, M. E.; Tasioula‐Margari, Maria; Spanier, A. M.; Shahidi, Fakhri; Parliment, T. H.; Mussinan, C.; Ho, Chi‐Tang; Contis, E. Tratras

doi:10.1039/9781847550859-00578

Cited by 8 publications

(13 citation statements)

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“…Hakansson and Jagerstad [10] showed that white flour lost up to 70-80% of its vitamin E at temperatures over about 150°C when heated for 15 min. Studies on a-tocopherol degradation in typical oil models such as olive oil and triolein were also reported [9,11,12]. The losses of a-tocopherol were 5.7% in triolein exposed to 180°C for 60 min at 40 mbar [9].…”

Section: Introductionmentioning

confidence: 99%

“…The highest loss of a-tocopherol (13.7%) was observed under 260°C for 80 min at 40 mbar. Nissiotis and Tasioula-Margari [12] found that samples of olive oil heated to 100°C at atmospheric pressure lost significantly more a-tocopherol than did samples heated at 60°C, which was reflected in the different time scales required to degrade 100% of the a-tocopherol. A complete degradation of a-tocopherol occurred in samples stored at 60°C for 30 days.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Temperature and UV Light on Degradation of α‐Tocopherol in Free and Dissolved Form

Sabliov

Fronczek

Astete

et al. 2009

J Americ Oil Chem Soc

113

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The effects of heat and UV exposure on the degradation of free a-tocopherol (oil form), a-tocopherol dissolved in methanol, and a-tocopherol dissolved in hexane were measured. Results showed that degradation of free a-tocopherol due to heat followed first order kinetics, with the samples held at 180°C showing the greatest degradation rate. Free a-tocopherol degraded faster at high temperatures than dissolved a-tocopherol. In contrast, free a-tocopherol did not degrade when exposed to UV light for as long as 6 h, but the hexane and methanol samples degraded significantly as a matter of time. The a-tocopherol dissolved in hexane and methanol degraded by 20 and 70%, respectively over this time span. A mechanism for degradation of a-tocopherol was proposed to explain the higher degradation rate of a-tocopherol in methanol, as compared to hexane for times longer than 180 min. Knowledge of degradation kinetics of pure a-tocopherol as a result of temperature or exposure to UVA light whether in free or dissolved form is critically needed to understand how different processing parameters affect the amount of a-tocopherol during extraction, stabilization, storage or encapsulation processes.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of Temperature and UV Light on Degradation of α‐Tocopherol in Free and Dissolved Form

Sabliov

Fronczek

Astete

et al. 2009

J Americ Oil Chem Soc

113

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show abstract

“…The higher phenol reduction observed for natural settling may be mainly explained by the washing effect proposed for this system, although the low oxidative stability of oleuropein derivatives (3,4-DHPEA-EDA and 3,4-DHPEA-EA) could also affect their contents during the settling process. 35,36 However, in general, individual phenols did not change their concentration when the oils were clarified by VCS, thus VCS with minimal water addition let to preserve the concentration of these natural antioxidants. As observed (Table 3), VCS oils showed higher 3,4-DHPEA-EDA and 3,4-DHPEA-EA contents than CBST oils (ANOVA, P ≤ 0.05).…”

Section: Effect On Virgin Olive Oilmentioning

confidence: 99%

Study of virgin olive oil clarification by settling under dynamic conditions

et al. 2018

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“…Nissiotis [23] reported in EVOO that hydroxytyrosol derivatives are the first antioxidants that are lost during thermal-oxidation (until a peroxide value of 20-30 meq/kg). The stated author also reported that other derivates such as tyrosol in EVOO seem to be the most stable compounds, while a-tocopherol has an intermediate rate of loss at low peroxide values and is destroyed at peroxide values from 20 to 50 meq/kg.…”

Section: Scalar Index: Odour Indexmentioning

confidence: 99%

Monitoring odour of heated extra‐virgin olive oils from Arbequina and Manzanilla cultivars using an electronic nose

Messina

Sancho²,

Reca

2015

Euro J Lipid Sci & Tech

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It is known that fats and oils, when submitted to prolonged heat, are subjected to a series of chemicalphysical modifications, generating changes in sensory and nutritional characteristics. The aim of the present research was to develop an accurate and repeatable method to predict appearance of undesired odour when extra-virgin olive oils from Arbequina and Manzanilla are submitted to heating processes, using an electronic nose. Among the metal oxide sensor response (electronic nose) an odour index was performed. Emissions of several volatile organic compounds released during the process were analysed by SPME-Gas chromatography. Linear discriminant analysis was applied on the sensor response; it was found that among eight sensors, four sensors were more specific for detecting release of volatile organic compounds during the heating process. The Mahalanobis distance method was adopted to create an odour index and was correlated with emissions of n-pentanal, n-hexanal, n-heptanal and n-nonanal. Data showed that the methodology accurately and rapidly predicted changes in odour pattern between cultivars.Practical applications: Changes in odour pattern of different cultivars of extra-virgin olive oil subjected to heating processes can be performed quickly and easily by applying electronic nose. Appearance of undesired odour due to thermo-oxidation can be detected applying an odour index based on the metal oxide sensors response. High correlations can be observed when linear regressions are applied to odour index and volatile compounds (VOCs) content. New markers of oxidation can be obtained applying this methodology. Electronic nose instruments are attractive for a number of significant features: the relatively fast assessment of headspace, a quantitative representation or signature of a gas and cheap sensors which can be easily integrated to quality control. The motivation of the present research was to incorporate metal oxide sensors in electronic nose as a useful tool to analyse the odour pattern and quality of different products.

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Changes in antioxidant concentration of virgin olive oil during thermal oxidation

Cited by 8 publications

References 0 publications

Effects of Temperature and UV Light on Degradation of α‐Tocopherol in Free and Dissolved Form

Effects of Temperature and UV Light on Degradation of α‐Tocopherol in Free and Dissolved Form

Study of virgin olive oil clarification by settling under dynamic conditions

Monitoring odour of heated extra‐virgin olive oils from Arbequina and Manzanilla cultivars using an electronic nose

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