Entering a supermarket here is a bizarre experience. Shelves are fully stocked with Scotch whiskey, Argentine wines and imported cheeses like brie and Camembert, but basic staples like black beans and desirable cuts of beef like sirloin are often absent. Customers, even those in the government’s own Mercal chain of subsidized grocery stores, are left with choices like pork neck bones, rabbit and unusual cuts of lamb.

With shoppers limited to just two large packages of sugar, a black market in sugar has developed among street vendors in parts of Caracas. “This country is going to turn into Cuba, or Chávez will have to give in,” said Cándida de Gómez, 54, a shopper at a private supermarket in Los Palos Grandes, a district in the capital.

José Vielma Mora, the chief of Seniat, the government’s tax agency, oversaw a raid this month on a warehouse here where officials seized about 165 tons of sugar. Mr. Vielma said the raid exposed hoarding by vendors who were unwilling to sell the sugar at official prices. He and other officials in Mr. Chávez’s government have repeatedly blamed the shortages on producers, intermediaries and grocers.

Those in the food industry argue that the price controls prevented them from making a profit after inflation rose and the value of Venezuela’s currency plunged in black market trading in recent weeks. The bolívar, the country’s currency, fell more than 30 percent to about 4,400 to the dollar in unofficial trading following Mr. Chávez’s nationalization of Venezuela’s main telephone company, CANTV, and its largest electric utility, Electricidad de Caracas.

Fears that more private companies could be nationalized have put further pressure on the currency as rich Venezuelans try to take money out of the country. Concern over capital flight has made the government jittery, with vague threats issued to newspapers that publish unofficial currency rates (officially the bolívar is quoted at about 2,150 to the dollar).

Regardless of efforts to stop illicit currency trading, the weaker bolívar has made imported food, fertilizers and agricultural equipment more expensive. Venezuela, despite boasting some of South America’s most fertile farmland, still imports more than half its food, largely from Argentina, Brazil, Colombia and the United States.

Supermarket owners expressed relief when the government this week cut value-added taxes on retail food sales and raised the prices on more than 100 staples in an effort to alleviate the shortages. The announcement included an average 32 percent increase in beef prices and a 45 percent increase in chicken prices.