How is ORAC value calculated?
ORAC-FL values were calculated as: ORACvalue=CTrolox×[(AUCsample–AUCblank)/(AUCTrolox– AUCblank)], where, CTrolox is molarity of Trolox. Final results were expressed in μmol of Trolox equivalent per gram of dry mass of the extrac ts (μmolTE/gDM).
How many types of antioxidant assays are there?
There are two general types of assays widely used for different antioxidant studies.
How do you measure antioxidant content?
ORAC Assay (The Oxygen Radical Absorbance Capacity) ORAC assay is a method for quantifying the antioxidant strength of substances. It involves combining the sample to be tested (i.e. the antioxidant) with a fluorescent compound as well as a compound that generates free radicals at a known rate.
What is FRAP method?
The ferric reducing antioxidant power (FRAP) assay is a typical ET-based method that measures the reduction of ferric ion (Fe3+)-ligand complex to the intensely blue-colored ferrous (Fe2+) complex by antioxidants in an acidic medium.
What is ABTS assay?
In biochemistry, ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) is a chemical compound used to observe the reaction kinetics of specific enzymes. A common use for it is in the enzyme-linked immunosorbent assay (ELISA) to detect the binding of molecules to each other.
Why is FRAP assay done?
The FRAP assay is used to measure the antioxidant power based on the reduction at low pH of ferric-tripyridyltriazine (Fe3 +-TPTZ) to an intense blue color ferrous-tripyridyltriazine complex (Fe2 +-TPTZ) with an absorption maximum at 593 nm.
How do you do ORAC assay?
The ORAC assay measures a fluorescent signal from a probe that is quenched in the presence of Reactive Oxygen Species (ROS). Addition of an antioxidant absorbs the generated ROS, allowing the fluorescent signal to persist.
What is ferric reduction tests?
Ferric reducing ability of plasma (FRAP, also Ferric ion reducing antioxidant power) is an antioxidant capacity assay that uses Trolox as a standard. This assay is often used to measure the antioxidant capacity of foods, beverages and nutritional supplements containing polyphenols.
Why ABTS assay is done?
Based on the special chemical properties of formed free radicals, ABTS assay has been used to determine the antioxidant capacity of food products. For example, polyphenol compounds, which widely exist in fruit, can quench free radicals inside human body, thus prevent oxidative damage by free radicals.
