The USDA found mandarin grown in Placer County, California contains high levels of a good-for-you ingredient that can help fight allergies and cold symptoms. NBC's Richard Sharp takes us to the orchard for the secret.

Joanne Neft has a love affair with Placer County mandarins.

"Oh I am pretty excited about mandarins, can you tell," Neft said. "If you stick your nose in to them, they are amazing."

Joanne was so excited she raised enough money, $16,000, for the USDA to study the fruit.

"I always believe that mandarins were pretty special, because every time mandarin season came around I felt a lot better," Neft said.

It turns out Joanne was right.

The USDA tested mandarins from 10 different micro-climates in Placer County and what they found inside these little fruits, compared to other citrus, 6 to 7 times the amount of synephrine, a naturally occurring decongestant. You can buy these mandarins from stores, online or straight from the growers.

The mandarins are in such a high demand they are sold nationally. Sold so fast they can't harvest them fast enough.

"We ship these all over the nation," said mandarin grower Tony Aguiar. "We have people from Minnestota, Nebraska, New York, that want these shipped right to them."

So it's no surprise Placer County mandarins are called the super citrus.

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