TOKYO — Considering the immensity of the earthquake and tsunami that hit Japan on March 11, the country’s basic food processing industry sustained little damage. The exception, of course, centered in the northeast section of the country where the damage from the twin natural disasters, along with severe damage to a nuclear power plant, have either shut down or severely interrupted operations at several plants in an area of Japan that is not heavily populated.

Most of the nation’s food industry, including flour mills and baking plants, is located to serve the Tokyo Bay area as well as the southern part of the nation where population is heaviest.

Operating difficulties in areas not directly affected by the earthquake and severe flooding were primarily the result of periodic power interruptions. Due to the breakdown at the Fukushima Daiichi nuclear power plant, electrical supplies were being rationed through rolling blackout. This was the practice of the Tokyo Electric Power Co., where blackouts of three to four hours per day were conducted in different areas served. At the same time, major factories such as the largest flour mills had their own power supplies and were not affected by the blackouts.

In turn, the rolling blackout disrupted transportation in a country that heavily counts on rail services to move people. Commuting problems have been severe in many areas, but the major food companies assert that they have had little or no production interruptions because employees could not reach plants.

As a nation that relies primarily on imported wheat to supply its flour mills, assuring an adequate supply for milling received high priority. A number of the nation’s largest flour mills are located adjoining port grain elevators equipped to unload ocean-going vessels that deliver wheat. Except for the port elevators in the northeast coastal area that were directly impacted by the earthquake and tsunami, delivery of wheat to mills has proceeded without interruption.

While flour and food products are mainly delivered by truck, and thus are not affected by the erratic train service, shortages of gasoline caused delays and difficulties. This was a problem greatly accentuated by the surge in demand for grain-based foods like bread and instant noodles that reflected the surge in demand by consumers anxious to establish home supplies. This rapid expansion in business came unexpectedly and has eased only a bit in response to governmental reassurances.

In an exchange with the headquarters of the Nisshin Seifun Group, which is Japan’s largest flour milling company with 10 flour mills, Milling & Baking News has learned that none of the company’s employees were lost or injured in the massive disaster. Crediting the company’s Business Continuity Plan, Nisshin said it organized a task force charged with emergency disaster control right after the earthquake struck.

“With regard to our production facilities, our flour mill in Hakodate, Hokkaido (northwest of Sendai), stopped its operations due to floods by the tsunami, and we are putting our repair efforts to resuming its operation as early as possible,” Nisshin said.

The company indicated that some other factories “were slightly damaged and stopped their operations temporarily, but they have recovered already.”

The Nisshin mills where production temporarily was halted by the earthquake were Tsurumi, Chiba and Tatebayshi. All have resumed full-scale operations.

A Showa Sangyo flour mill in the region hardest hit by the disaster was not operating. Several area port elevators also were closed, but this was not seen as a major source of imported wheat.

Nisshin said that all of its plants have continued shipments without interruption. At the same time, it acknowledged difficulties in supplying product “to meet the unexpected demands not only in the area damaged by the earthquake and tsunami but also in the Tokyo metropolitan area.”

The company has a sales office in Sendai, described as the social and economic center of northern Japan and a city hard hit by the earthquake and subsequent flooding. A Nisshin sales office was damaged and the company’s main distribution center in Sendai was damaged.

“We are taking necessary steps for restoration and we are trying our best to supply products to the market,” the company said. “Complete recovery is expected within a few days.”

In view of the widespread media attention focused on the nuclear plant problems, the Food and Agriculture Organization of the United Nations issued a report saying that “there is no evidence of food safety risks because of imports from Japan.” The F.A.O. added that “food safety concerns are restricted to food from the affected zone around the Fukushima Daiichi nuclear power plant.” It added, “Given the reported safety measures, it would be unlikely that food production or harvesting is taking place in the evacuated area.”