scholarly journals Determination of the Thermal Oxidation Stability and the Kinetic Parameters of Commercial Extra Virgin Olive Oils from Different Varieties

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Ana Malvis ◽  
Peter Šimon ◽  
Tibor Dubaj ◽  
Alexandra Sládková ◽  
Aleš Ház ◽  
...  

The use of olive oil with cooking purposes, as final seasoning or within cooked foods is increasing worldwide due to its numerous nutritional and health benefits. These attributes are mainly determined by olive oil chemical composition, which can be altered after thermal processing, oxidation processes, or incorrect practices. For this reason, and due to the numerous factors which have influence in olive oil quality, the correct chemical characterization is highly relevant. In this study, fatty acid composition of four extra virgin olive oil (EVOO) varieties was studied. The major fatty acid (FA) determined was oleic acid (77.1% on average), followed by palmitic (11.5% on average). In addition, thermal oxidation behaviour of the four EVOO samples was studied as an indicator of their quality and stability during thermal processing. This was performed through differential scanning calorimetry (DSC) from a temperature of 40°C at six different heating rates in the range of 0.5–10°C min−1. DSC records showed the same pattern and a small shoulder in the thermo-oxidation peak was present for all samples and all heating rates. The presence of initial and final oxidation products (by monitoring K232 and K270 values, respectively) was discarded according to the International Olive Council method.

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4079 ◽  
Author(s):  
Jingnan Chen ◽  
Dami Li ◽  
Guiyun Tang ◽  
Jinfen Zhou ◽  
Wei Liu ◽  
...  

The stability of soybean germ phytosterols (SGPs) in different lipid matrixes, including soybean germ oil, olive oil, and lard, was studied at 120, 150, and 180 °C. Results on the loss rate demonstrated that SGPs were most stable in olive oil, followed by soybean germ oil, and lard in a decreasing order. It is most likely that unsaturated fatty acids could oxidize first, compete with consumption of oxygen, and then spare phytosterols from oxidation. The oxidation products of SGPS in non-oil and oil systems were also quantified. The results demonstrated that at relatively lower temperatures (120 and 150 °C), SGPs’ oxidation products were produced the most in the non-oil system, followed by lard, soybean germ oil, and olive oil. This was consistent with the loss rate pattern of SGPs. At a relatively higher temperature of 180 °C, the formation of SGPs’ oxidation products in soybean germ oil was quantitatively the same as that in lard, implying that the temperature became a dominative factor rather than the content of unsaturated fatty acids of lipid matrixes in the oxidation of SGPs.


OCL ◽  
2020 ◽  
Vol 27 ◽  
pp. 44
Author(s):  
Mohamed El Yamani ◽  
El Hassan Sakar ◽  
Abdelali Boussakouran ◽  
Yahia Rharrabti

The activity of natural additives against the deterioration of virgin olive oil (VOO) in relation to storage time and conditions was examined. Thus, carotenoids and phenols previously extracted from carrot and olive mill wastewater, respectively, were added at 200 and 400 ppm to VOO and stored in clear and amber glass bottles at room temperatures during 120 days. The results showed that enriched VOO was largely influenced by the storage time, which resulted in a significant accumulation of hydrolysis and oxidation products. Storage conditions also affected considerably the enriched VOO. Dark glass bottles offered better protection against oxidative deterioration. The impact of both extracts on the oxidation status of examined VOO was significant and concentration-dependent. The natural additives markedly delayed the formation of hydroperoxides and conjugated dienes and trienes. Results from principal component analysis (PCA) showed that most of the variation was captured by the PC1 (89% of the total variance) which grouped samples in four categories according to storage times, each being divided into two clusters linked to storage conditions. Findings from this study revealed that natural additives could minimize VOO deterioration caused by storage time and conditions (light).


2021 ◽  
Vol 141 ◽  
pp. 322-329
Author(s):  
Jihed Faghim ◽  
Mbarka Ben Mohamed ◽  
Mohamed Bagues ◽  
Kamel Nagaz ◽  
Tebra Triki ◽  
...  

2020 ◽  
Vol 15 (1) ◽  
pp. 606-618 ◽  
Author(s):  
Dani Dordevic ◽  
Ivan Kushkevych ◽  
Simona Jancikova ◽  
Sanja Cavar Zeljkovic ◽  
Michal Zdarsky ◽  
...  

AbstractThe aim of this study was to simulate olive oil use and to monitor changes in the profile of fatty acids in home-made preparations using olive oil, which involve repeated heat treatment cycles. The material used in the experiment consisted of extra virgin and refined olive oil samples. Fatty acid profiles of olive oil samples were monitored after each heating cycle (10 min). The outcomes showed that cycles of heat treatment cause significant (p < 0.05) differences in the fatty acid profile of olive oil. A similar trend of differences (p < 0.05) was found between fatty acid profiles in extra virgin and refined olive oils. As expected, the main differences occurred in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). Cross-correlation analysis also showed differences between the fatty acid profiles. The most prolific changes were observed between the control samples and the heated (at 180°C) samples of refined olive oil in PUFAs, though a heating temperature of 220°C resulted in similar decrease in MUFAs and PUFAs, in both extra virgin and refined olive oil samples. The study showed differences in fatty acid profiles that can occur during the culinary heating of olive oil. Furthermore, the study indicated that culinary heating of extra virgin olive oil produced results similar to those of the refined olive oil heating at a lower temperature below 180°C.


Author(s):  
Sonia Tomé‐Rodríguez ◽  
Carlos A Ledesma‐Escobar ◽  
José M Penco‐Valenzuela ◽  
Feliciano Priego‐Capote

Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 1937-1946
Author(s):  
M.M.D.R. Tugay ◽  
L.E. Mopera ◽  
E.B. Esguerra ◽  
K.A.T. Castillo-Israel

This study aimed to characterize and compare pili (Canarium ovatum Engl.) pulp oil from two different varieties of pili fruits in Bicol, Philippines namely M. Orolfo and Orbase varieties for possible utilization into oil-based products. The effects of varietal differences in pili fruits on physical, chemical and quality characteristics of its pulp oil were determined. These two oils were also compared with control oils, commercially available coconut oil and extra virgin olive oil. Pili pulp oil from M. Orolfo had dark color while Orbase had color close to extra virgin olive oil. The two varieties did not significantly differ from each other in terms of refractive index, moisture and volatile matters, acid value, iodine value, saponification number and percent unsaponifiable matter but significantly differed from coconut oil and extra virgin olive oil. On the other hand, the two varieties significantly differed from each other in terms of peroxide value, Vitamin A and α-tocopherol contents. In terms of fatty acid profile, high amounts of palmitic acid were determined in both pili varieties (19-25%) compared with coconut oil (6.34%). Oleic acid in Orbase was 71.5% while M. Orolfo had 58.1%, which are comparable with extra virgin olive oil (77.9%). Pili pulp oils from M. Orolfo and Orbase can be utilized into oilbased products because its chemical and quality characteristics are within the standard. Both can be stored for a longer period of time and healthier in terms of fatty acid composition and natural antioxidant content.


2014 ◽  
Vol 4 (4) ◽  
Author(s):  
Maurizio Caciotta ◽  
Sabino Giarnetti ◽  
Fabio Leccese ◽  
Barbara Orioni ◽  
Marco Oreggia ◽  
...  

2018 ◽  
Vol 12 (3) ◽  
Author(s):  
E. Ghanbari Shend ◽  
D. Sivri Ozay ◽  
M . T. Ozkaya ◽  
N. F. Ustunelc

In this study Turkish monocultivar extra virgin olive oil (EVOO) “Sarı Ulak” was extracted by using the Mobile Olive Oil Processing Unit (TEM Oliomio 500-2GV, Italy). Changes in minor and major components and quality characteristics, free fatty acid content, peroxide value and UV absorbance value, were surveyed during a year’s storage period. “Sarı Ulak” olive oil samples were classified as EVOO according to the trade standards of the International Olive Council (IOC) based on free fatty acid, peroxide value, K232 and ΔK values up to the eighth month of the storage period. The results have shown that color values of EVOO changed from green to yellow slowly while UV absorbance values changed during storing. Total polyphenol content of extra virgin olive oil decreased from 205.17 ppm to 144.29 ppm during a year’s storage. Luteolin was the most abundant phenolic compound, and its concentration changed from 184.33 ppm to 115.06 ppm. Apigenin concentration was differed from 2.67 to 1.06 ppm during storing. The initial level of α-tocopherol contents was 184.51 ppm, it decreased to 147 ppm at the end of storage time. After 12 months of storing, about 20 % of α-tocopherol content was destroyed. The amounts of phenolic and tocopherol isomers decreased during storage as expected.


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