The ethnic diversity found in the northern California population has given rise to a number of brokers and distributors who focus on specialty fruits and vegetables.

“A significant amount of our volume on the market and of our customers is on the international side,” said Michael Janis, general manager at the San Francisco Wholesale Produce Market.

Yuet Cheong & Co. Inc., on the market for about 10 years, started with a focus on Chinese buyers and has expanded to include Korean, Japanese and Thai customers, said partner Robert Lee.

Because the company’s business is about half ethnic restaurants and half mom-and-pop grocery stores, sales tend to remain strong whether consumers are dining out or eating at home, Lee said.

Choy sum, gai lan and yu choy are some of Yuet Cheong’s most popular Asian items, Lee said.

Local sources of ethnic items were winding down in early September, said Steve Chen, owner of Fresh Green Inc., also on the San Francisco Wholesale Produce Market, and the company expected to start sourcing early-season Chinese eggplant and long beans from Mexico by early October.

Fresh Green also sells items like white long beans, squash, sugar plums and okra from Mexico and the U.S., Chen said.

Most of the company’s customers are Asian, but the firm also provides product to some U.S. brokers and distributors.

The product line at Carcione’s Fresh Produce Co. Inc. at the Golden Gate Produce Terminal in South San Francisco includes products that appeal to Asian, Mexican, Central American, Indian and Arab consumers, said Beto Gomez, head salesman.

Business has been slow at Mercado Latino on the San Francisco Wholesale Produce Market because of the sagging economy, said manager Robert Rodriguez.

Mercado Latino offers a variety of items for the Hispanic community, including root vegetables like taro, yucca and nami, which Rodriguez said is “a true yam” with a nutty taste that can be stored for two to three years if conditions are right.

The company also sells green and ripened plantains and saba bananas, Florida avocados and dried spices.

Mercado Latino makes local deliveries to its customers, which are largely Hispanic restaurants and grocery stores, Rodriguez said.

The specialties category also remains strong in the northern California market despite the recession, said Eric Kane, general manager at Coosemans San Francisco Inc. on the San Francisco Wholesale Produce Market.

Many new items are turning up, including finger limes — a premium-priced, finger-size lime from Australia that has a flesh that resembles caviar, he said.

Sales of many high-dollar items have slowed, but overall sales were up last year at Stanley Produce Co. Inc., another merchant on the San Francisco Wholesale Produce Market that features specialty produce, said Stanley Corriea Jr., president.