K.C. Cole, "Genetically Altered Food Unnatural? Not Really," Los Angeles Times, October 21, 1999
'Tomatoes May Be Dangerous to Your Health' (Op-Ed, June 1) by Sheldon Krimsky is right to question the decision of the Food and Drug Administration to exempt genetically engineered crops from case-by-case review. Ever since Mary Shelley's baron rolled his improved human out of the lab, scientists have been bringing just such good things to life. If they want to sell us Frankenfood, perhaps it's time to gather the villagers, light some torches and head to the castle.
Newton Center, Mass., June 2, 1992"
"Mutant Foods Create Risks We Can't Yet Guess," The New York Times, June 16, 1992
Interestingly, Mr. Lewis also seems to be the coiner of the word schmooseoisie. Note, however, that Mr. Lewis' letter is not the earliest print usage of Frankenfood. Here's one from a few months earlier, albeit with a totally different sense:
Nancy Ross Ryan, "Reinventing the meal," Restaurants & Institutions, March 11, 1992
farm to fork