Antioxidant Beverages

It may be money that makes the world go ’round, but it’s oxidation that makes the world run down. The same cascade of reactions that converts shiny metal to rusty junk converts richly flavored and colored foods to rancid and pale-looking, and ravage the human body by causing an array of debilitating diseases and conditions.

“Consumers are becoming more and more aware of what an antioxidant is and the health benefits antioxidants can provide,” says Heather Biehl, senior scientist, HITS, WILD Flavors, Inc., Erlanger, KY. “Because of the increased awareness, the interest of consumers in antioxidants is growing and the beverage market is responding to consumers’ interest by developing more products with the added benefits of antioxidants.” Beverages are a key vehicle for these compounds.

Quantifiable results

Oxygen radical absorption capacity (ORAC) is a means of expressing the antioxidant power of a given food. Developed in 1993, the ORAC test compares a substance’s ability to quench free radicals to that of a standard—a vitamin E derivative called Trolox or gallic acid. ORAC scores are reported in Trolox equivalents (TE) or gallic acid equivalents (GAE) per unit weight of sample.

Other tests have been developed, including ferric ion reducing antioxidant power (FRAP) and Trolox equivalence antioxidant capacity (TEAC) assays. Results from these tests are not directly comparable with ORAC values. While some experts would argue the ORAC assay produces misleading results, a 2007 government report, “Oxygen Radical Absorption Capacity (ORAC) of Selected Foods,” states that the ORAC assay is “considered by some to be a preferable method because of its biological relevance to the in vivo antioxidant efficacy.”

A-C-E in the hole

Several vitamins act as antioxidants. The first, vitamin A, may occur in several active forms, including the alcohol form (retinol), the aldehyde form (retinal) and an acid form (retinoic acid).

Vitamin A is a member of the carotenoid family, a group of roughly 700 oil-soluble polyunsaturated compounds displaying a range of colors from bright-yellow to deep-red, depending on the number and position of their double bonds. Carotenoids that terminate with a cyclic hydrocarbon group are called carotenes and include compounds like lycopene. Xanthophylls such as lutein and zeaxanthin possess an additional oxygen-containing functional group.

Five double bonds and a free hydroxyl group make vitamin A susceptible to oxidation during processing and/or shelf life—especially when pH is below 5. Developers, therefore, often turn to beta carotene. A more-stable compound than retinol, beta carotene is converted to vitamin A in the body at a rate of approximately 6:1. And, while Vitamin A toxicity (upper limit 3,000 mcg per day) can cause birth defects, beta carotene’s only known side effect from overdosing is yellowing of the skin.

Vitamin C, ascorbic acid, is a crucial element in the production of collagen, norepinephrine and carnitine synthesis, and cholesterol metabolism. A strong antioxidant, vitamin C is known for prohibiting oxidative reactions by sequestering the metals that catalyze them, and helping prevent formation of free radicals in cellular fluids by donating hydrogen atoms from its two hydroxyl positions. Vitamin C also rejuvenates vitamin E to an antioxidant form.