Biochemical parameters and oxidative resistance to thermal treatment of refined and unrefined vegetable edible oils

In human nutrition fats are physiologically important food constituents but also the components most liable to oxidative degradation. The oils included in the study were refined (sunflower, extra-sunflower, soybean, and rapeseed) as well as unrefined (olive and pumpkin-seed) oils. The aim of our study was to determine the fatty acid composition, tocopherol content, and quality parameters such as the free fatty acid content, peroxide value, and induction time. Extra virgin olive oil had the highest average peroxide value, while unrefined pumpkin seed oil had the lowest one. The acid value of the unrefined oils was higher on average than that of the refined oils. Soybean oil had the highest total tocopherol content and extra virgin olive oil the lowest one. The refined oils with higher contents of saturated and monounsaturated fatty acids and lower polyunsaturated fatty acid contents had a high oxidative stability. A negative correlation has been found in the oils between the induction time and polyunsaturated fatty acid content. Among the oils investigated, unrefined pumpkin seed oil was the most oxidatively stable, the other oils following in the decreasing order: extra virgin olive > high oleic sunflower > rapeseed > soybean > sunflower oil. The oxidative stability of the unrefined oils was better than that of the refined oils.

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Determination of some chemical and quality parameters of changes in turkish Sari Ulak monocultivar extra virgin olive oil during 12 months of storage

Food Science and Technology ◽

10.15673/fst.v12i3.1038 ◽

2018 ◽

Vol 12 (3) ◽

Author(s):

E. Ghanbari Shend ◽

D. Sivri Ozay ◽

M . T. Ozkaya ◽

N. F. Ustunelc

Keyword(s):

Fatty Acid ◽

Free Fatty Acid ◽

Olive Oil ◽

Peroxide Value ◽

Fatty Acid Content ◽

Virgin Olive Oil ◽

Storage Period ◽

Extra Virgin Olive Oil ◽

Processing Unit ◽

Uv Absorbance

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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Chemical characterization and storage stability of extra virgin olive oil extracted from Derik Halhalı cultivar

Croatian Journal of Food Science and Technology ◽

10.17508/cjfst.2019.11.1.08 ◽

2019 ◽

Vol 11 (1) ◽

pp. 52-58

Author(s):

Esmael Ghanbari Shendi ◽

Dilek Sivri Özay ◽

Mücahit Taha Özkaya ◽

Nim,eti Feyza Üstünel

Keyword(s):

Fatty Acid ◽

Free Fatty Acid ◽

Olive Oil ◽

Free Fatty Acid Content ◽

Acid Content ◽

Fatty Acid Content ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Processing Unit ◽

Uv Absorbance

Turkish olive cultivar known as “Halhalı” that is locally grown in Mardin (Derik) province, situated in the southeast Anatolia, was used for virgin olive oil (VOO) production. Halhalı olive was processed in the “Mobile Olive Oil Processing Unit” (TEM Oliomio 500-2GV, Italy) designed as the first mobile olive mill in Turkey. Some chemical and physical properties (colour, UV absorbance values, free fatty acid content, peroxide value, phenolic and tocopherol profiles) were determined and monitored during one year of storing in the dark at room temperature once in every three months. Results showed that up to the eighth month of storage, free fatty acid content, peroxide and UV-absorption values (K232 and K232 values) did not exceed the limits reported by International Olive Council (IOC) and olive oils were categorized as Extra Virgin Olive Oil (EVOO). Colour changed from green to yellow and UV absorbance values altered during storage. Total phenol and vitamin E (α- tocopherol) contents decreased by 18% and 16.38%, respectively. Luteolin and apigenin were the most abundant phenolics and their contents decreased up to 22% and 28% during storing, respectively.

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A comparison studies on the chemical characteristics of pumpkin seed oil with extra virgin olive oil and palm olein

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/260/1/012091 ◽

2019 ◽

Vol 260 ◽

pp. 012091

Author(s):

N A Agustina ◽

J Elisabeth ◽

E Julianti

Keyword(s):

Olive Oil ◽

Palm Olein ◽

Seed Oil ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Chemical Characteristics ◽

Pumpkin Seed ◽

Pumpkin Seed Oil

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Changes occurring in chemical composition and oxidative stability of virgin olive oil during storage

OCL ◽

10.1051/ocl/2018052 ◽

2018 ◽

Vol 25 (6) ◽

pp. A602 ◽

Cited By ~ 5

Author(s):

Esmaeil Ghanbari Shendi ◽

Dilek Sivri Ozay ◽

Mucahit Taha Ozkaya ◽

Nimeti Feyza Ustunel

Keyword(s):

Fatty Acid ◽

Chemical Composition ◽

Free Fatty Acid ◽

Olive Oil ◽

Peroxide Value ◽

Storage Time ◽

Fatty Acid Content ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Uv Absorbance

In present study, “Saurani” Turkish olive monocultivar extra virgin olive oil (EVOO) was extracted by using Mobile Olive Oil Processing Unit (MOOPU)” (TEM Oliomio 500-2GV, Italy). Free fatty acid content, peroxide value, moisture content and UV absorbance value, minor and major components and quality characteristics changes were surveyed during a year storage. “Saurani” olive oil samples weren’t categorized as EVOO according to the trade standards of International Olive Council (IOC) based on peroxide value, UV absorbance values after five and two months of storing, respectively. Free fatty acid content of VOO samples increased during 12 months’ storage, but it was under the IOC limitation for extra virgin olive oil (< 0.8%). According to the results, color values of VOO changed from green to yellow while UV absorbance values altered during storage. Total phenol content decreased from 342.95 to 252.42 ppm in EVOO samples during a year storage time. Luteolin was the most abundant phenolic compound and its decrement was 10%. Tyrosol content of VOO samples increased from 2.80 to 8.81 ppm. Except tyrosol, other phenolic compounds’ concentration decreased after a year storage time. α-tocopherol contents of VOO sample were 324.60 ppm. After 12 months of storage, about 20.48% of α-tocopherol content was destroyed. Amounts of phenolic and tocopherol isomers decreased during storage as expected. Results of this study showed that chemical composition and oxidative stability of VOO samples changed significantly.

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