Antioxidant activity of raspberry (Rubus fruticosus) leaves extract and its effect on oxidative stability of sunflower oil

In this study, Pelvetia canaliculata L. macroalga, collected from the Atlantic Portuguese coast, was used as a source of bioactive compounds, mostly antioxidants, to incorporate them in sunflower oil with the aim of increasing its biological value and oxidative stability. The lyophilized alga was added to the oil, and ultrasound-assisted extraction (UAE) was performed. Algae concentration and UAE time varied following a central composite rotatable design (CCRD) to optimize extraction conditions. The following parameters were analyzed in the oils: oxidation products, acidity, color, chlorophyll pigments, carotenoids, flavonoids, total phenolic content, antioxidant activity by DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, and sensory analysis. Extraction conditions did not affect the acidity and the amount of oxidation products in the oil. Chlorophylls and carotenoid contents increased with algae concentration, while flavonoid extraction did not depend on algae content or UAE time. Total phenolics in the oil were highly related only to FRAP antioxidant activity. Storage experiments of supplemented oil (12.5% algae; 20 min UAE) were carried out under accelerated oxidation conditions at 60 °C/12 days. Antioxidant activity (FRAP) of supplemented oil was 6-fold higher than the value of non-supplemented oil. Final samples retained 40% of their initial antioxidant activity. The presence of algae extracts contributed to the increased oxidative stability of sunflower oil.

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Oxidative Stability of Sunflower Oil Supplemented with Medicinal Split Gill Mushroom, Schizophyllum commune Fr.:Fr. Extract during Accelerated Storage

International Journal of Medicinal Mushrooms ◽

10.1615/intjmedmushr.v13.i4.60 ◽

2011 ◽

Vol 13 (4) ◽

pp. 357-368

Author(s):

Hip Seng Yim ◽

Fook Yee Chye ◽

Pei Ying Heng ◽

Chun Wai Ho

Keyword(s):

Oxidative Stability ◽

Sunflower Oil ◽

Schizophyllum Commune ◽

Accelerated Storage

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Comparison of Bioactive Compounds of Matricaria recutita Extracted by Ultrasound and Maceration and their Effects on Preventing Sunflower Oil During Frying

Current Nutrition & Food Science ◽

10.2174/1573401313666170712110248 ◽

2019 ◽

Vol 15 (2) ◽

pp. 156-164 ◽

Cited By ~ 1

Author(s):

Reza Farahmandfar ◽

Maryam Asnaashari ◽

Yegane Asadi ◽

Batool Beyranvand

Keyword(s):

Antioxidant Activity ◽

Gallic Acid ◽

Bioactive Compounds ◽

Sunflower Oil ◽

Radical Scavenging ◽

Stability Index ◽

Acid Value ◽

Extraction Methods ◽

Oil Stability Index ◽

Matricaria Recutita

Background: It is important to study about the use of natural antioxidants as alternatives to synthetic ones due to the possibility of carcinogenic effects of synthetic antioxidants. This study is comparing the effect of the ultrasound-assisted and maceration extraction methods on antioxidant activity of Matricaria recutita. Methods: Bioactive compounds including phenolic, tocopherol, flavonoid and tannins and antioxidant activity of the extracts were evaluated. Moreover, extracts obtained from ultrasound and maceration methods were added to sunflower oil without any antioxidants at level of 200, 500 and 800 ppm, after that samples were heated at 180°C. Oxidation of the samples were evaluated after 0, 4, 8, 12, 16, 20 and 24 hours by measuring Peroxide Value (PV), Conjugated Diene (CD), Iodine Value (IV), Carbonyl Value (CV), Total Polar Compounds (TPC), Oil Stability Index (OSI), Color Index (CI) and acid value (AV). Results: The result showed total phenol (42.90 mg gallic acid/g extract), tocopherol (120.46 µg α - tocopherol/ml extract), flavonoid (2.64 mg/100 g extract) and tannins (3.89 mg gallic acid/g extract) of ultrasound extracts were higher than maceration extracts. Antioxidant activity of the extract was evaluated by DPPH assay which indicated 800 ppm of the Matricaria recutita extracted by ultrasound was the highest radical scavenging ability. Conclusion: Result indicated both ultrasound and maceration extracts could increase the oil oxidative stability but could not increase compared to BHA. In most cases, the extract samples by ultrasound had a better effect on stabilizing of sunflower oil during frying.

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