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.
The effect of particle size and solvent type on the gallic acid yield obtained from Labisia pumila by ultrasonic extraction
