Synthesis and oxidative stability of hyperbranched macromolecule-bridged hindered phenols

The intramolecular synergistic effects of two dendritic antioxidants between hindered phenol groups and tertiary amine groups were investigated using the DPPH˙ method and the oxygen uptake method.

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A novel antioxidant action of ethanolamine plasmalogens in lowering the oxidizability of membranes

Biochemical Society Transactions ◽

10.1042/bst0320141 ◽

2004 ◽

Vol 32 (1) ◽

pp. 141-143 ◽

Cited By ~ 15

Author(s):

R. Maeba ◽

N. Ueta

Keyword(s):

Free Radicals ◽

Oxygen Uptake ◽

Water Soluble ◽

Antioxidant Action ◽

Unilamellar Vesicles ◽

Radical Initiator ◽

Large Unilamellar Vesicles ◽

Ethanolamine Plasmalogens ◽

Uptake Method

We have demonstrated a novel antioxidant action of ethanolamine plasmalogens both in protecting cholesterol from oxidation by free radicals and in lowering the oxidizability of membranes, along with the action of scavenging radicals, by the oxygen-uptake method using large unilamellar vesicles and the water-soluble azo-radical initiator, AAPH [2,2´-azobis-(2-amidino-propane) dihydrochloride].

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Improvement of the Oxidative Stability of Sesame Oil Using Spirulina as a Natural Antioxidant

Journal of Nutrition and Food Security ◽

10.18502/jnfs.v3i4.165 ◽

2018 ◽

Author(s):

Shima Omidi ◽

Hamid Sarhadi ◽

Fatemeh Shahdadi

Keyword(s):

Oxidative Stability ◽

Antiradical Activity ◽

Methanol Extract ◽

Antioxidant Properties ◽

Sesame Oil ◽

Butylated Hydroxytoluene ◽

Natural Antioxidant ◽

Synthetic Antioxidants ◽

Methanol Extracts ◽

Dpph Method

Background: Nowadays, natural antioxidants are used to replace synthetic antioxidants for delaying or preventing the oxidation of edible oils. In this study, phenolic compounds and antioxidant properties of methanol extracts of Spirulina microalgae (Arthrospira platensis) were measured. Methods: Phenolic content was measured by Folin–Ciocalteau method and antioxidant activity was measured by the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method. Also, spirulina microalgae as natural antioxidant, was added to sesame oil for improving its oxidative stability. The effects of methanol extract of these microalgae in four concentrations (0, 500, 1000 and 2000 ppm) and synthetic antioxidants of butylated hydroxyl anyzole (BHA) and butylated hydroxytoluene (BHT) in two levels (100 and 200 ppm) in retarding the sesame oil oxidation were examined. Results: The results showed that spirulina extract had 50.54 mg gallic acid/g samples total phenols and antiradical activity (84.38%). By increasing the concentration of the extracts, the oxidation process decreased. Methanol extract at 1000 ppm concentration had the highest antiradical activity than other concentrations and its antiradical activity was alike the synthesis antioxidant of BHA. By Increasing of storage period, peroxide values in 500 and 1000 ppm of spirulina extracts first increased then decreased and in other treatment increased. During storage time thiobarbituric acid index increased. However, this increase was higher in control treatment than others. Conclusion: According to the stated content, it can be said that methanol extracts of spirulina have appropriate antioxidant properties and spirulina can be used as a natural antioxidant to improve the oxidative stability of sesame oil.

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Antioxidant capacity, oxidative stability of mango (Mangifera indica L) seed oil in 2 varieties and two degrees of maturity

TAYACAJA ◽

10.46908/tayacaja.v4i2.169 ◽

2021 ◽

Vol 4 (2) ◽

pp. 29-39

Author(s):

Elza Berta Aguirre Vargas ◽

María de Fátima Arévalo Oliva ◽

Magda Isabel Javier Villanueva ◽

Gilbert Rodriguez-Paucar

Keyword(s):

Oxidative Stability ◽

Antioxidant Capacity ◽

Seed Oil ◽

Unsaturated Fatty Acids ◽

Mangifera Indica ◽

Nitrogen Atmosphere ◽

Total Polyphenols ◽

Dpph Method ◽

Significant Difference ◽

Degree Of Maturity

The present work search the influence of the Edward and Kent mango varieties, in degrees of maturity partially ripe and ripe respectively, on the antioxidant capacity and oxidative stability of mango seed oil (Mangifera indica L.), previously extracted by pressing in cold, clarified by centrifugation, and stored in refrigeration under nitrogen atmosphere. The antioxidant capacity is determine by DPPH method, the oxidative stability by the Rancimat test with temperature parameters 130, 140 and 150 °C, and airflow 15 L/h. The results are evaluate by ANOVA (p˂0, 05) finding in the antioxidant capacity and other analyzes made a significant difference with a level of 95% confidence in the variables of variety and degree of maturity. Regarding the influence, the relationship will be determined that in a mature degree of maturity has a higher content of unsaturated fatty acids (oleic), and a lower content of total polyphenols, antioxidant capacity and oxidative stability. Being the oil of the variety Edward in degree of maturity ripe the most stable due to low value of the peroxide index (0,898 meq O2 / kg), acidity (1,1856%), and the higher content of total polyphenols (8,5931 mg GAE /100g) and antioxidant capacity (263,858 umoltrolox /100g), with a lifetime of 12,89 years.

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Effect of Ultrasound-Treated Arabinoxylans on the Oxidative Stability of Soybean Oil

Antioxidants ◽

10.3390/antiox9020147 ◽

2020 ◽

Vol 9 (2) ◽

pp. 147 ◽

Cited By ~ 1

Author(s):

Mayra A. Mendez-Encinas ◽

Elizabeth Carvajal-Millan ◽

Jesús Ortega-García ◽

Lubitza B. Santiago-Gómez ◽

Yubia De Anda-Flores ◽

...

Keyword(s):

Antioxidant Activity ◽

Soybean Oil ◽

Oxidative Stability ◽

Antioxidant Capacity ◽

Ultrasonic Treatment ◽

Potential Application ◽

Average Molecular Weight ◽

Natural Antioxidant ◽

Attractive Alternative ◽

Dpph Method

Arabinoxylans (AX) are polysaccharides with antioxidant activity and emulsifying properties, which make them an attractive alternative for its potential application as a natural antioxidant in oils. Therefore, this work aimed to investigate the effect of ultrasonic treatment of AX on their antioxidant capacity and its ability to improve the oxidative stability of soybean oil. For this purpose, AX were exposed to ultrasonic treatment at 25% (100 W, AX-1) and 50% (200 W, AX-2) power and an operating frequency of 20 KHz during 15 min, and their macromolecular properties (weight average molecular weight (Mw), polydispersity index and intrinsic viscosity) were evaluated. The antioxidant capacity of AX was determined by the DPPH assay and Rancimat test. Results showed that ultrasonic treatment did not affect the molecular identity of the polysaccharide but modified its Mw distribution. AX-1 showed the highest antioxidant activity (75% inhibition) at 533 µg/mL by the DPPH method compared to AX and AX-2. AX at 0.25% (w/v) and AX-1 at 0.01% (w/v) exerted the highest protective effects on oxidative stability of soybean oil with induction periods of 7.69 and 5.54 h, respectively. The results indicate that AX could be a good alternative for the potential application as a natural antioxidant in oils.

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Study of the Antioxidant Power of the Waste Oil from Palm Oil Bleaching Clay

Energies ◽

10.3390/en13040804 ◽

2020 ◽

Vol 13 (4) ◽

pp. 804

Author(s):

Katiane Cunha de Melo ◽

Ingrid Silva de Oliveira ◽

Luiza Helena de Oliveira Pires ◽

Luís Adriano Santos do Nascimento ◽

José Roberto Zamian ◽

...

Keyword(s):

Oxidative Stability ◽

Palm Oil ◽

Bleaching Clay ◽

Synthetic Antioxidants ◽

Waste Oil ◽

Antioxidant Power ◽

Oil Fraction ◽

Worldwide Production ◽

Dpph Method ◽

Other Substances

Palm oil is one of the most consumed oils, one of whose refining steps is the removal of pigments and other substances using bleaching clay as adsorbent. Worldwide production of this oil was 70 million tons in 2017, requiring 1 t of clay to produce 1000 t of refined oil. The residual bleaching clay, having an oil fraction (12.70%) rich in phenolics, carotenoids and tocopherols, was extracted in this study with ethanol to obtain an antioxidant-rich palm oil bleaching extract (POBE), with the aim of using it as a natural antioxidant source. The POBE antioxidant capacity determined by the DPPH method corresponded to a 20.29% inhibition of radical formation. The POBE was also tested for its potential to enhance oxidative stability of passion fruit, pracaxi and Brazil nut oils used as reference oils, and compared to common synthetic antioxidants (tert-butylhydroquinone and propyl gallate), either separately as controls or in mixtures with them. Besides the increased oxidative stability of these oils induced by the POBE, a positive synergistic effect between it and the synthetic antioxidants was observed. These results taken together suggest that the exploitation of the waste oil from bleaching clay as an additive to improve the oxidative stability of biofuels or lubricating oils is feasible.

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