| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1187258 | Food Chemistry | 2010 | 7 Pages |
In vitro antioxidant activities and protective effects in stabilising sunflower oil of three rosemary extracts high in carnosic acid (CA) were tested. The CA contents (w/w) of the extracts were 24.9% (CA25), 60.5% (CA60) and 98.3% (CA98). Total phenolic contents of CA25 and CA60 were (3.58 ± 0.026 g/100 g) and (8.20 ± 0.027 g/100 g), (3.91 ± 0.029 g/100 g) and (8.10 ± 0.056 g/100 g) expressed in gallic acid and catechin equivalents, respectively. Reducing power of CA and other antioxidants at 0.5 mg/ml followed the order of l-ascorbic acid > CA98 > TBHQ > BHA > CA60 > BHT > CA25. The IC50 values in the DPPH assay obtained for CA25, CA60, CA98, BHA, BHT and TBHQ were 0.30 ± 0.002, 0.20 ± 0.003, 0.12 ± 0.002, 0.19 ± 0.002, 0.42 ± 0.010, and 0.09 ± 0.001 mg/ml, respectively.Protective effects of CA in stabilising sunflower oil were tested, compared to synthetic antioxidants, by measuring their peroxide values, thiobarbituric acid-reactive substances, free fatty acid contents and p-anisidine value during accelerated storage. Results indicated that CA exhibited stronger antioxidant activity in sunflower oil than BHT and BHA. However, its antioxidant activity was less than that of TBHQ.
