Antioxidant Potential of Plant-based Food Ingredients

Originally Published: October 9, 2015
Last Updated: October 9, 2015
Some spices and herbs have natural antioxidant properties, suitable for use in clean label products.
2015 Clean Label Conference, Jin Ji, PhD, Brunswick Laboratories, Chart on antioxidants and radical source in vegetables.

The original ORAC assay only measures antioxidant capability of a material against the peroxyl free radical. ORAC 5.0 adds four additional free radical values to that of peroxyl, which results in a higher ORAC value that does not always correlate with the traditional ORAC value. Click on image for larger version of this chart. 

–October 9, 2015–Global Food Forums, Inc. — The following is an excerpt from the “2015 Clean Label Report,” sponsored by Loders Croklaan, RiceBran Technologies and SunOpta.

Antioxidants are a group of molecules, abundant in plant foods, with unique chemical structures that allow them to scavenge free radicals. Although antioxidants have been used in the food industry since the 1800s, their popularity soared around 2000, as scientists began to understand the role of free radicals in creating oxidative stress and how that stress acerbated chronic diseases, including inflammation and cancer, and age-related chronic disorders.

“Antioxidants have two primary uses in foods—extending shelflife by preserving food; and enhancing nutritional value and health benefits,” explained Jin Ji, Ph.D., Chief Technology Officer & Executive Vice President at Brunswick Laboratories, Inc. Both exogenous forces, such as heat and light, and endogenous components, such as transitional metals, contribute to the process of oxidation.

Natural antioxidants have a long history of use in North America, dating back to Native Americans. In 1920, the antioxidant industry emerged and initially focused on synthetic antioxidants, such as BHA and BHT. In the 1980s, the trend shifted to natural antioxidants. Antioxidants fall into several major groups. The first is phenolic compounds, which are found mostly in seeds, berries, herbs and spices. The second group is tocopherols, which are isomers of vitamin E and occur primarily in nuts, seeds and vegetable oils. Other sources include ascorbic acid, citric acid and carotenoids.

“A food formulator needs to first quantify the antioxidant level. Brunswick Laboratories provides ORAC assay, or Oxygen Radical Absorption Capacity, a quick and cost-effective method to quantify antioxidants,” added Ji.

Using test methods that are accurate and repeatable, the industry has developed robust databases that enable food formulators to select an optimal antioxidant ingredient based on ORAC values. Industry has also developed quick, industry-specific methods to
quantify specific antioxidant sub-groups, such as phenolic compounds and anthocyanins. When an even more targeted approach is needed, labs can “fingerprint” specific antioxidant constituents.

An ORAC database was first introduced by the USDA in 2007, with the initial release containing data on 277 food items. After widespread misinterpretation by consumers, the USDA withdrew the database from their website in 2012. ORAC values are expressed as μmol of Trolox Equivalents (TE). In order for the data to be properly interpreted, one must note whether the TE values are per 100g or per serving.

Spices generally have high ORAC values, as do cocoa and pomegranate. The original ORAC assay only measures antioxidant capability of a material against only one free radical—peroxyl—when, in fact, many foods contain multiple free radicals, noted Ji.

A newer measure, ORAC 5.0, evaluates against all five primary radicals. (See chart “Radical Source and Antioxidant Capacity of Vegetables.”) Both ORAC and ORAC 5.0 values are available on the Brunswick Laboratories website at

Food formulators need to know how a specific antioxidant ingredient will perform in their food system. Important questions to explore include availability, cost-effectiveness, stability and compatibility with the other components of the food. Another consideration
is whether to choose a synthetic or a natural antioxidant. Antioxidants have potential to promote mental sharpness and heart health; and to reduce cancer, inflammation and vision problems. Label claims can be supported through preclinical studies
and, ultimately, clinical trials.

Ji reminds food formulators that in the competitive food market, “Science-backed products will win.”

Jin Ji, Ph.D., Chief Technology Officer & Executive Vice President, Brunswick Laboratories, Inc.,, 1-508-281-6660,