Adria told the newspaper El Mundo that the chemicals he uses have been part of haute cuisine for years.
"I don't understand (this controversy). It's nonsense, from a legal and health standpoint," said Adria, whose restaurant El Bulli on Spain's northern Catalan coast was in April named the world's best for the third year in a row by Britain's Restaurant magazine.
"Homemade ice-creams, those which are excellent, must have a stabilising substance to avoid crystallisation. Sugar goes through a chemical and physical transformation. Chocolate contains lecithin. Agar is a thick substance that has been used in Japan for centuries."
"The tomato also has a chemical composition," he said.
He was responding to accusations by another top Spanish chef, Santi Santamaria, that his cuisine had harmful health effects.
"Can we be proud of a cuisine ... created by Ferran Adria and his chorus of fans which fills plates with gelling agents and laboratory emulsifiers?," he wrote in a column published in the Catalan daily La Vanguardia last month.
"We are facing a public health problem," added Santamaria, a self-taught chef who is a fond of using locally-sourced produce at his El Can Fabes bistro near Barcelona which also has three Michelin stars.
The criticism provoked a war among top Spanish chefs, between those who were pro- and anti-Adria.
"We must all have our freedom," Adria told El Mundo, adding that the real debate should be about "the limits of haute cuisine."
Adria, 46, and Heston Blumenthal in England have since the late 1990s rocked the world cuisine by using science to "deconstruct" and rebuild food, both bluffing diners and delighting reviewers.
Taste-bud treats on the menu of Adria's three-star restaurant have included oyster meringue, hot ice cream, frothy truffle cappuccino and liquid ravioli, while vegetables are turned into lollipops or whipped foams.