'Shocking' technique could bring fresher, healthier juice

GRIFFIN,Ga. - For many orange juice fans, there is nothing quite like the taste of fresh-squeezed, just off the tree, unprocessed juice.

But if that juice in your glass is not pasteurized, Jim Gratzek, the director of The University of Georgia's Food Product Innovation Commercialization Center, says it can harbor harmful bacteria that can make you pretty miserable.

"Well, they're the classic ones that you hear about in the news - listeria, salmonella, E.coli," says Gratzek. "Especially if you're immunocompromised, they're trouble. Even if you're a healthy individual, they'll make you sick."

That's why most of the juice you buy at the store is pasteurized, or treated with very high heat, to kill bacteria. But that can also affect the taste.

So Gratzek and his team at UGA's Griffin campus are working with a company called Food Physics on a new way to process juice with less heat.

 It's something pulse electrical field (or PEF) technology: using bursts of electricity to shock the juice and kill the bacteria, yeast or mold.

"We're talking 20,000 volts per centimeter, that's a lot of volts," Gratzek explains.

This technology is already used to soften potatoes used to make french fries.

To test it out, the UGA team is using a Georgia-made satsuma orange juice blend and watermelon lemon juice blend, to process the juice without losing the fresh-squeezed taste.

"If we can get it right, we are talking about 20, 30, 40 degrees Fahrenheit lower temperature for things like milk and most juices and other things like almond milk and oat milk and coconut milk," Gratzek says.

In a taste test, Gratzek says, volunteers felt their samples tasted "fresher" that commercially-made juice, although the juice is still technically processed.

"And, those elements of fresh squeezed are still there. And that's what a lot of people value for a premium juice," Gratzek says. "Compared to normal pasteurization, more vitamin C will survive or more fresh taste will prevail."

The food scientist predicts the technique will be used on other food types.

"If the wholesomeness and initial quality of a foodstuff is better maintained as a result of the process, the food could be expected to be en masse healthier," he says.