Preserving Mayo with Purple Corn Extract

Mayo is a much-liked sauce, but the same kind words cannot be said of its usual preservatives. For the mayo manufacturer who doesn’t want to use BHT and EDTA for preservation, purple corn extract now looks like a viable alternative-if only for one strange consequence.

Reporting in Food Chemistry, a team of researchers in Korea studied the effect of adding purple corn husk extract to mayo. At 0.4 g/kg, the extract provided better storage stability than BHT and EDTA, as measured by the amount of hydroperoxides (oxidative products) that developed in mayo over 10 weeks.

“This study suggests that PCHE could be used as a natural antioxidant in high fat food and as a substitute to chemical antioxidant, with its purplish color marking its difference from ordinary mayonnaise,” concluded the researchers.

That’s right. Purple mayo. If a manufacturer is able to market purple mayo, purple corn husk extract can be an effective and quite clean-label preservative. Mayo without its characteristic white color could be a challenge to market-such was the case with green ketchup-but the researchers contend that “Such color difference will tell consumers that their food contains natural antioxidants.” With the proper marketing, they could be right about purple mayo.

Purple corn gets its purple color from anthocyanins, and these compounds are primarily responsible not just for coloring, but also for the type of food preservation witnessed by in this recent study. Other commercial sources of anthocyanin sold throughout the world include sweet potatoes, blackberry juice, and lingonberries.

For now, purple corn extract is very much a niche ingredient, but maybe that’s because suppliers tend to market extracts that are based on corn kernels. The husk may contain as much as 10 times more anthocyanins than the kernel, and yet an internet search of this particular corn ingredient yields very few results right now.