Some find pasteurized almond rule unsavory

Raw, organic almonds form the basis of Karyn Calabrese’s garlicky nut pate, her vegan pie crusts and vanilla ice cream custards.

But under a new federal rule requiring that virtually all almonds be pasteurized to prevent food-borne illness, the Chicago restaurateur will have to substitute a new nut, or go to vast lengths to import her raw almonds from across the globe.

Industry representatives say tightening food safety rules to subject almonds to heat treatment will help expand the market for California farmers, who grow about 80% of the world’s almonds.

But the regulation, set to take effect Sept. 1, has angered many including organic farmers and followers of the raw foods diet.

“The almond is the king of the nut world and a main staple for raw foodists,” said Calabrese, whose elegant restaurants feature small plates of raw, vegan food, none of which has been heated above 110 degrees.

Almonds have become increasingly lucrative as they’ve gained popularity with health-conscious consumers. California farmers expect to harvest 1.3 billion pounds of almonds this year, worth more than $1.4 billion.

After salmonella outbreaks in 2001 and 2004 that were traced to raw almonds, the Almond Board of California rallied for a federal rule requiring all almonds in the state to be pasteurized to keep bacteria from infecting the nuts while they dry in the orchard or while they’re processed.

“We consider it unacceptable to continue shipping a product that could contain a microorganism that could make somebody sick,” said Richard Waycott, president and chief executive of the board, a marketing arm of the U.S. Department of Agriculture.

In pasteurization, the shelled and hulled nuts typically are laid out on a conveyor belt that passes them through a moist burst of steam to heat the kernels’ surface to about 200 degrees, killing any pathogens present. An alternative process sends the nuts into a chamber where they’re sprayed with propylene oxide gas.

Major almond buyers such as Mars Inc., Kraft Foods Inc. and Hershey Co. reviewed a study by the board to determine whether the process affected the nut’s quality, taste, texture and appearance, and found it had no effect, Waycott said.

Once treated, the pasteurized almonds can be legally shipped throughout the U.S., Canada and Mexico, said Michael Durando, chief for the marketing order administration branch at USDA.

Growers can apply for exemptions if they can prove that their manufacturing process -- be it dry roasting, blanching or any other traditional treatments -- achieves pasteurization. They also can sell small quantities of raw, unpasteurized almonds direct to customers at farm stands or at certified California farmers markets .

That’s not enough volume for Berkeley-based Living Tree Community Foods, which soon will start importing its raw almonds from Spain to make its “living” nut butter. Company officials said its customers were concerned about the health effects of propylene oxide.