scholarly journals Effect of antioxidants on stability, nutritional values of refined sunflower oil during accelerated storage and thermal oxidation in frying

2012 ◽  
Vol 47 (2) ◽  
pp. 223-230 ◽  
Author(s):  
H Akhtar ◽  
I Tariq ◽  
S Mahmood ◽  
S Hamid ◽  
R Khanum
Keyword(s):  
Elevated Temperature ◽  
Thermal Oxidation ◽  
Sunflower Oil ◽  
Antioxidant Activities ◽  
Protective Effects ◽  
Pet Bottles ◽  
Frying Process ◽  
Accelerated Storage ◽  
Sunflower Oils ◽  
The Stability

Untreated sunflower oil (without antioxidants) was much more affected during long storage as well as by the thermal oxidation in 4 hours  frying process. The shelf life of oil was increased both during storage and in frying process at elevated temperature by the addition of synthetic  antioxidants. TBHQ (Tertiory butyl hydroquinone) BHT (Butylated hydroxyl toluene) BHA (Butylatd hydroxyl amine) and the mixture  of BHA and BHT used in the present study in 0.02, 0.02, 0.02 and 0.01+0.01 amount respectively to observe the stability of refined  sunflower when stored at 30°C for 21 weeks in transparent PET bottles. The stored oils (treated and untreated) when underwent in the  process of frying at the temperature of 180°C further deterioration of oils happened. The antioxidant activities and protective effects in stabilization  of sunflower oils during storage and in frying process measured in terms of POV (peroxide), FFA (free fatty acids), p-AnV (p- Anisidine value), Colour Index, RI (Refractive index), and fatty acid profile. Result indicated that TBHQ exhibited stronger antioxidant  activity during storage and gave maximum protection against thermal oxidation when oil subjected in the process of multiple frying for continous  four hours at elevated temperature. The results were indicated the effectiveness of antioxidants in the order like TBHQ > BHT > BHA  BHA+BHT. DOI: http://dx.doi.org/10.3329/bjsir.v47i2.11458 Bangladesh J. Sci. Ind. Res. 47(2), 223-230, 2012

scholarly journals The intake of fried virgin olive or sunflower oils differentially induces oxidative stress in rat liver microsomes

2002 ◽  
Vol 88 (1) ◽  
pp. 57-65 ◽  
Author(s):  
José L. Quiles ◽  
Jesús R. Huertas ◽  
Maurizio Battino ◽  
M. Carmen Ramírez-Tortosa ◽  
Modesta Cassinello ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Olive Oil ◽  
Rat Liver ◽  
Sunflower Oil ◽  
Virgin Olive Oil ◽  
Liver Microsomes ◽  
Rat Liver Microsomes ◽  
Frying Process ◽  
Sunflower Oils

The effects of non-fried and fried virgin olive and sunflower oils on rat liver microsomal compositional features have been investigated. In addition, plasma antioxidants (α-tocopherol and ubiquinone 9) were investigated as well as the possible oxidative modifications suffered by virgin olive and sunflower oils during the frying process. The frying process decreased the content of α-tocopherol and phenolics in the oils and increased total polar materials. Sunflower oil was affected to a greater extent than olive oil. In rats, the intake of fried oil led to higher levels of lipid peroxidation and a lower concentration of plasma antioxidants. Microsomal fatty acid and antioxidant profiles were also altered. It seems that a strong relationship exists between the loss of antioxidants and the production of toxic compounds in the oils after frying and the extent of the peroxidative events in microsomes, which were also different depending on the fat source. The highly unsaturated sunflower oil was less resistant to the oxidative stress produced by frying and led to a higher degree of lipid peroxidation in liver microsomesin vivothan virgin olive oil.

scholarly journals The effect of fatty acid profile on the stability of non-traditional and traditional plant oils

10.5219/1064 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 744-750
Author(s):  
Josef Soukup ◽  
Lenka Kouřimská
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Sunflower Oil ◽  
Plant Oils ◽  
Weight Changes ◽  
High Oleic ◽  
Peroxide Values ◽  
Sunflower Oils ◽  
The Stability

The effect of fatty acid composition on the autoxidation of selected plant oils (rapeseed (canola) oil, corn oil, frying oil, grapeseed oil, pomace olive oil, rice bran oil, sunflower oil and high oleic sunflower oil) during their storage was studied. Oils were purchased in retail food stores. Oxidative stability of plant oils was monitored during the storage under the Schaal test conditions at 60 °C in 100 mL beakers and the dark for 40 days. The weight changes, the peroxide and acid values were analysed during the storage. Changes in the composition of fatty acids were analyzed by the gas chromatography-mass spectrometry. The results obtained by monitoring the weight changes of oils correlated with their peroxide values. The induction period in case of grapeseed and sunflower oils was 27 and 28 days respectively. The induction period for frying and rapeseed oils were around 35 days. The remaining four oils had induction periods over 40 days. The acid values at the end of experiment correspond to both the relative weight gain and the the peroxide values. The stability of oils depended mainly on the degree of fatty acids unsaturation. A strong negative correlation between oleic acid content and oil stability expressed as the peroxide value was found. The significant positive correlation was found in case of linoleic acid. The relative content of polyunsaturated fatty acids decreased during the storage while the content of saturated and monounsaturated fatty acids increased. The highest relative increase in oleic acid was found at the least stable oils, grapeseed and sunflower oils, by 37.5% and 25.3% respectively. The initial content of free fatty acids monitored by the acid value did not affect the oxidation rate. With consideration to all monitored parameters the grapeseed and the sunflower oils were the least stable. The most stable ones were olive pomace and high oleic sunflower oils.

scholarly journals Thermo-degradative changes of rapeseed and sunflower oils during deep-frying French fries

10.5219/1080 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 138-149
Author(s):  
Lucia Zeleňáková ◽  
Mária Angelovičová ◽  
Marek Šnirc ◽  
Jana Žiarovská ◽  
Stanislav Kráčmar ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Peroxide Value ◽  
Sunflower Oil ◽  
Rapeseed Oil ◽  
Acid Value ◽  
French Fries ◽  
Deep Frying ◽  
Frying Process ◽  
Sunflower Oils ◽  
Initial Content

The purpose of this study was to investigate changes in TPCs, acid value and peroxide value as well as fatty acids composition in edible oils during french fries production. Lower TPCs content was found in rapeseed oil (3.3%) and the threshold (24%) was achieved on the fourth day. The total time for the deterioration of deep-frying rapeseed oil was 23½ hours. On the contrary, in fresh sunflower oil at the first day was TPCs content 5.5% and the limit of 24% was reached on the third day. The total time for the deterioration of deep-frying sunflower oil was 17½ hours. The results indicated significant differences (<0.05) in TPCs content between rapeseed and sunflower oils during deep-frying process. At the beginning of deep-frying French fries in rapeseed oil, the acid number was 0.374 mg KOH.g-1 and 1.271 mg KOH.g-1 at the fourth day of deep-frying. The measured peroxide value was 4.3 mEq O2.kg-1 at the beginning and at the end of deep-frying 10.5 mEq O2.kg-1. The initial peroxide and acid values were higher in sunflower oil compared with rapeseed oil, respectively. It should be note, then the acid values and peroxide values, respectively, in the two fresh oils used in this study were below the limit of refined oil according to Slovak legislation (peroxide value - not more than 10 mEq O2.kg-1, acid value - not more than 0.6 mg KOH.g-1). However, detected values varied during deep-frying process. Monounsaturated fatty acids were predominantly observed in fresh rapeseed oil (61.22%) wherever in sunflower oil they were much lower (29.77%). A slight increase of MUFA was found in both oils. The initial content of saturated fatty acids in rapeseed oil was 6.94%, in fresh sunflower oil was observed slightly higher content of SFA (10.37%). The major groups of fatty acids in fresh sunflower oil were polyunsaturated fatty acids (PUFA) which have in principle a significant effect on oil deterioration. A slight decrease of PUFA was observed in both oils throughout the frying period. The content of PUFA was reduced by about 9.42% in rapeseed oil and by 10.8% in sunflower oil. The initial content was 28.14% and 58.91%, respectively.

scholarly journals Lemon Balm and Dandelion Leaf Extracts Synergistically Protect against Carbon Tetrachloride-Induced Acute Liver Injury in Mice

2021 ◽  
Vol 11 (1) ◽  
pp. 390
Author(s):  
Beom-Rak Choi ◽  
Il-Je Cho ◽  
Su-Jin Jung ◽  
Jae-Kwang Kim ◽  
Dae-Geon Lee ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Liver Injury ◽  
Acute Liver Injury ◽  
Antioxidant Activities ◽  
Body Weight Gain ◽  
Histopathological Analysis ◽  
Related Factor ◽  
Mrna Levels ◽  
Protective Effects ◽  
Lemon Balm

Lemon balm and dandelion are commonly used medicinal herbs exhibiting numerous pharmacological activities that are beneficial for human health. In this study, we explored the protective effects of a 2:1 (w/w) mixture of lemon balm and dandelion extracts (MLD) on carbon tetrachloride (CCl4)-induced acute liver injury in mice. CCl4 (0.5 mL/kg; i.p.) injection inhibited body weight gain and increased relative liver weight. Pre-administration of MLD (50–200 mg/kg) for 7 days prevented these CCl4-mediated changes. In addition, histopathological analysis revealed that MLD synergistically alleviated CCl4-mediated hepatocyte degeneration and infiltration of inflammatory cells. MLD decreased serum aspartate aminotransferase and alanine transferase activities and reduced the number of liver cells that stained positive for cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase, suggesting that MLD protects against CCl4-induced hepatic damage via the inhibition of apoptosis. Moreover, MLD attenuated CCl4-mediated lipid peroxidation and protein nitrosylation by restoring impaired hepatic nuclear factor erythroid 2-related factor 2 mRNA levels and its dependent antioxidant activities. Furthermore, MLD synergistically decreased mRNA and protein levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6 in the liver. Together, these results suggest that MLD has potential for preventing acute liver injury by inhibiting apoptosis, oxidative stress, and inflammation.

scholarly journals Antioxidant activity of mandarin (Citrus reticulata) peel

2010 ◽  
pp. 195-203 ◽  
Author(s):  
Vesna Tumbas ◽  
Gordana Cetkovic ◽  
Sonja Djilas ◽  
Jasna Canadanovic-Brunet ◽  
Jelena Vulic ◽  
...  
Keyword(s):  
Radical Scavenging Activity ◽  
Waste Product ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Protective Effects ◽  
Dpph Radical ◽  
Esr Spin Trapping ◽  
Accelerated Storage ◽  
Mandarin Peel ◽  
Peel Extract

Mandarin peel, a waste product coming from juice production, was extracted by conventional extraction with 70% acetone. Content of flavonoids in mandarin peel extract (MPE) was determined by HPLC. Hesperidin was the most dominant flavonoid. Free radical scavenging activity of MPE on stable DPPH radicals and reactive hydroxyl radicals was also evaluated. EC50 value determined in spectrophotometrical DPPH radical assay was 0.179 mg/ml, while this value in ESR spin trapping hydroxyl radical assay was 0.415 mg/ml. Also, MPE showed protective effects in stabilising sunflower oil during accelerated storage. The results indicated that mandarin peel can be a valuable source of natural antioxidants.

scholarly journals Thermal Stability of Residual Stresses in Differently Deep Rolled Surface Layers of Steel SAE 1045

2021 ◽  
Author(s):  
Stephanie Saalfeld ◽  
Thomas Wegener ◽  
Berthold Scholtes ◽  
Thomas Niendorf
Keyword(s):  
Thermal Stability ◽  
Elevated Temperature ◽  
Residual Stresses ◽  
Elevated Temperatures ◽  
Fatigue Behavior ◽  
Decisive Role ◽  
Deep Rolling ◽  
Material Conditions ◽  
The Stability ◽  
Thermal Stability Of

AbstractThe stability of compressive residual stresses generated by deep rolling plays a decisive role on the fatigue behavior of specimens and components, respectively. In this regard, deep rolling at elevated temperature has proven to be very effective in stabilizing residual stresses when fatigue analysis is conducted at ambient temperature. However, since residual stresses can be affected not only by plastic deformation but also when thermal energy is provided, it is necessary to analyze the influence of temperature and time on the relaxation behavior of residual stresses at elevated temperature. To evaluate the effect of deep rolling at elevated temperatures on stability limits under thermal as well as combined thermo-mechanical loads, the present work introduces and discusses the results of investigations on the thermal stability of residual stresses in differently deep rolled material conditions of the steel SAE 1045.

scholarly journals A Polysaccharide Purified from Morchella conica Pers. Prevents Oxidative Stress Induced by H2O2 in Human Embryonic Kidney (HEK) 293T Cells

2018 ◽  
Vol 19 (12) ◽  
pp. 4027 ◽  
Author(s):  
Na Xu ◽  
Yi Lu ◽  
Jumin Hou ◽  
Chao Liu ◽  
Yonghai Sun
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activities ◽  
Average Molecular Weight ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Ultrastructural Observation ◽  
Protective Effects ◽  
Ferrous Ions ◽  
Nuclear Condensation ◽  
Morchella Conica

Morchella conica Pers. (M. conica) has been used both as a medical and edible mushroom and possesses antimicrobial properties and antioxidant activities. However, the antioxidant properties of polysaccharides purified from M. conica have not been studied. The aim of this study was to investigate the in vitro antioxidant properties of a polysaccharide NMCP-2 (neutral M. conica polysaccharides-2) purified from M. conica, as determined by radical scavenging assay and H2O2-induced oxidative stress in HEK 293T cells. Results showed that NMCP-2 with an average molecular weight of 48.3 kDa possessed a much stronger chelating ability on ferrous ions and a higher ability to scavenge radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) than the other purified fraction of NMCP-1 from M. conica. Moreover, 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetra-zolium bromide (MTT) assay showed that NMCP-2 dose-dependently preserved cell viability of H2O2-induced cells. The NMCP-2 pretreated group reduced the generation of reactive oxygen species (ROS) content and increased the mitochondria membrane potential (MMP) levels. In addition, Hoechst 33342 staining revealed cells treated with NMCP-2 declined nuclear condensation. Ultrastructural observation revealed that NMCP-2 pretreatment alleviated the ruptured mitochondria when exposed to H2O2. Furthermore, western blot analysis showed that NMCP-2 prevented significant downregulation of the protein expression of Bax, cleaved caspases 3, and upregulated Bcl-2 levels. These results suggest the protective effects of NMCP-2 against H2O2-induced injury in HEK 293T cells. NMCP-2 could be used as a natural antioxidant of functional foods and natural drugs.

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