Donald W. Riester, 64, former deputy director of the Bureau of Foods in the Food and Drug Administration, died of cancer Wednesday at a hospital in Santa Rosa, Calif., where he had lived since 1978.

He joined FDA here in 1972 as assistant director for packaging and served successively as deputy director for technology, then deputy director and director of the Bureau of Foods. He retired in 1978.

Mr. Riester, who had been a key member of the FDA task force that developed a manufacturing practices regulation to improve the safety of canned foods, received two FDA Awards of Merit.

Before joining FDA, he spent 35 years with the American Can Co., starting as a chemist and concluding his service as vice president and director of research and development. During his tenure, he had lived in New York, Wisconsin, Tampa, Fla., and Barrington, Ill.

Mr. Riester was born in Louisville, Ky., and grew up in Frankfort, Ky. He graduated from the University of Kentucky with a degree in industrial chemistry and took graduate work at the University of Chicago, Columbia University and the University of California at Los Angeles.

He was the author or coauthor of numerous technical publications on the food industry.

He was a member of the American Chemical Society, the Institute of Food Technologists, the American Association for the Advancement of Science, the Society of Plastic Engineers and the Industrial Research Institute.

He was on the boards of the Research and Development Association for Military Food and Packaging Systems and the Research Directors Association of Chicago.

He is survived by his wife, Ethel, of Santa Rosa; two sons, James and Jeffrey, of Appleton, Wis.; a daughter, Joan Mitschelen, of Kokomo, Ind.; a sister, Mary R. Brooks, of Lawrence, Kan., and five grandchildren.