Fred Hillig, 87, who worked for the Food and Drug Administration for more than 35 years before retiring as a supervisory chemist in 1962, died of a cerebral infarction Sept. 24 at Georgetown University Hospital where he had undergone hip surgery. He lived in Washington.

Mr. Hillig was the author of more than 100 technical works on food chemistry. He was the 1955 winner of the American Chemical Society's Borden Award. The award was for his "outstanding research in the chemistry of milk." The Society also was cited for providing the first easy method of detecting butter made from inferior cream and an improved method for measuring the fat content of milk.

He also received the superior service award from the old Department of Health, Education, and Welfare in 1955. He was a fellow of the Association of Official Analytical Chemists, and a charter member of Atlantic Fisheries Technological Conference.

Mr. Hillig was a native of Illinois and a 1922 graduate of George Washington University. He was a civilian employe of the Navy Department during World War I.

He was a member of St. Ann's Catholic Church in Washington.

Survivors include his wife of 58 years, Dorothy G., of Washington; a son, Dr. Bernard of Silver Spring; a daughter, Jane F. Strauss of Malvern, Pa., and seven grandchildren.