What are antioxidant assays?

Assays developed to evaluate the antioxidant activity of plants and food constituents vary. Therefore, to investigate the antioxidant activity of chemical(s), choosing an adequate assay based on the chemical(s) of interest is critical. There are two general types of assays widely used for different antioxidant studies.

How do you test for antioxidant activity?

Many popular methods to assess antioxidant activity are based on the competitive reaction of radicals with the antioxidant or with a probe, whose transformation can be monitored by fluorimetry (e.g., the ORAC assay), by spectrophotometry (e.g., the crocin bleaching assay), EPR (e.g., spin-trapping methods), or other …

How do you test for polyphenols?

Test Principle Polyphenols are placed in contact with a colored complex in an alcoholic solution and oxidized, thus discoloring the complex. Discoloration, measured at 630 nm (end-point), is directly proportional to the concentration of polyphenols in the sample and expressed in mg/L of gallic acid.

What are antioxidant activities?

Antioxidant activity can be defined as a limitation or inhibition of nutrient oxidation (especially lipids and proteins) by restraining oxidative chain reactions. From: Olives and Olive Oil in Health and Disease Prevention (Second Edition), 2021.

What substances have antioxidant activity?

Good sources of specific antioxidants include:

  • allium sulphur compounds – leeks, onions and garlic.
  • anthocyanins – eggplant, grapes and berries.
  • beta-carotene – pumpkin, mangoes, apricots, carrots, spinach and parsley.
  • catechins – red wine and tea.
  • copper – seafood, lean meat, milk and nuts.

What is FRAP assay used for?

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.

What is total phenolic content assay?

TPC activity is the process to figure out the amount of phenolic content in the samples. Phenolic compounds that contained in the plants have redox properties, and the properties allow them acting as antioxidants [6.

What are polyphenols?

Polyphenols are micronutrients that naturally occur in plants. They’re included in many supplements, though they’re also easy to get in your diet from foods like fruits, vegetables, teas, and spices. There are more than 8,000 types of polyphenols, which include: Flavonoids like quercetin and catechins in fruits.

How is antioxidant activity measured in plants?

In general, the antioxidant potential of the plant samples is routinely assessed by three approaches such as (a) direct measurement of antioxidant enzymes activity, (b) in vitro radical scavenging and reducing power assessment and (c) measuring the protective response of plant samples against chemical-induced oxidative …

What is DPPH assay used for?

It is a rapid, simple, inexpensive and widely used method to measure the ability of compounds to act as free radical scavengers or hydrogen donors, and to evaluate antioxidant activity of foods. It can also be used to quantify antioxidants in complex biological systems, for solid or liquid samples.