Producers of cold and allergy pills may face competition from an unexpected source – the mandarin orchards of Placer County.

A recent study by the U.S. Department of Agriculture confirms that Placer's popular Owari Satsuma mandarins pack a big jolt of synephrine, a natural antihistamine that relieves cold and allergy symptoms.

Scientists have known since the 1960s that citrus fruit, such as oranges, contain synephrine, but the health experts overlooked the mandarin.

It took the fundraising knack of Placer agriculture advocate Joanne Neft to spur the new study that documents the synephrine punch of locally grown mandarins.

"I always believed that Placer County mandarins had lots of synephrine," Neft said. "Every time I ate them, I felt so much better and my sniffles went away.

"But you can't say there is something special about them unless you have the data."

So, Neft raised $16,000 for the study at the USDA's Western Regional Research Center in the Bay Area town of Albany.

The research showed that juice from Placer mandarins tested had up to six times as much synephrine as the same quantity of orange juice, the only citrus previously tested.

Ten ounces of mandarin juice contain as much synephrine as one over-the-counter decongestant pill, according to the study.

Since the results were released, and thanks to some TV news reports picked up nationally, Placer's mandarin business has been booming.

The good publicity caught grower Curt Miller by surprise.

"I called Joanne the next day to raise some hell because I didn't know it was going to be on," Miller said with a laugh. "I needed more help to handle orders and people coming in."

Miller has about 2,700 mandarin trees on 6 acres in Penryn. He ships to almost every state and said orders have jumped since first reports of the study earlier this fall.

Grower Tony Aguilar, whose Highland Orchard is near Miller's, has seen similar results.

"Sales are way up from last year," he said. Orders even have come from the San Joaquin Valley, home of vast mandarin orchards.

Neft – who started the Mountain Mandarin Festival that's expected to draw 40,000 people to the Gold Country Fairgrounds in Auburn this weekend – says Placer mandarins also taste better.

"We did a blind tasting of mandarins from seven other growing areas," she said, "and Placer ranked far above the rest in complexity and flavor."

She credits the region's terroir – a term, mostly used for wine grapes, for the combination of location, climate, soil and water that creates unique flavor and characteristics.

Whether Placer mandarins have more synephrine than other varieties, however, has not been studied.

In fact, Klaus Draqull, a researcher who worked on the study, said Satsuma mandarins from other areas likely would have similar results.

That's fine with Aguilar.

"We came up with the money," the veteran grower said. "We did the study, and the first guy there wins."

Though Placer mandarins get plenty of attention, they are not a huge industry. The county has 65 registered growers and about 150 producing acres, said Nancyjo Riekse, the current county agriculture marketing director.

In 2007, the mandarin crop was about 625 tons and had a value of $1.2 million, she said.

That barely made the county's top 10 commodity list, led by rice at $11 million, nursery products at $10 million, and cattle at $9 million.

Production of mandarins is expected to drop 40 percent this year, she said. Mandarin yields fluctuate greatly, and some growers, such as Miller, are expecting to be down by 80 percent for unknown reasons.

"That's Mother Nature," he said Wednesday on a walk through his hilly orchard.

But higher prices should keep the county's crop value level with 2007, Riekse said.

And the future is bright, partly thanks to the synephrine study. Next up, perhaps: A more detailed study that would measure how fast synephrine from mandarin juice enters the blood stream and how long it lasts.

That study will cost $100,000, Neft said, but $40,000 has been raised.

Some local growers also are starting to process mandarin juice. Neft expects others to follow suit.

Meanwhile, she is filling 200 two-cup containers with mandarin juice and freezing them.

"We have allergies in this house in March, April and May," she said. "Last year, I drank mandarin juice, and my allergies disappeared."

Call The Bee's Bob Walter, (916) 773-7388.