In the world of haute cuisine it ranks as the ultimate heresy. A food writer has had the temerity to accuse Ferran Adria, often described as the world’s best chef, of inadvertently poisoning diners with additives.

Adria, who presides over El Bulli, near Barcelona, inspires a reverence usually reserved for rock stars as he experiments with frozen foams and oyster cubes that many regard more as art than cookery.

His restaurant is booked for years in advance but Jörg Zipprick, a German food writer, is unimpressed with this high temple of “molecular gastronomy” and says menus should carry health warnings informing diners of the additives in the dishes.

“These colorants, gelling agents, emulsifiers, acidifiers and taste enhancers that Adria has introduced massively into his dishes to obtain extraordinary textures, tastes and sensations do not have a neutral impact on health,” says Zipprick, adding that some have a laxative effect.

Molecular cooks also use polysaccharides from seaweed, which Zipprick says are suspected of causing intestinal cancer. Adria’s response is that the chemicals he uses have been part of haute cuisine for years and he denies his dishes pose any risk to health.

Zipprick is not the only one querying Adria’s use of ingredients more often associated with food processing than with haute cuisine. His book, The Unappetising Underside of Molecular Cooking, followed last year’s attack on Adria by Santi Santamaria, another top Spanish chef, who asked in a newspaper: “Can we be proud of a cuisine which fills plates with gelling agents and laboratory emulsifiers?”

Most of Adria’s countrymen consider him a national treasure and have been inclined to put Santamaria’s outburst down to jealousy. While pro-Adria chefs signed a petition calling his rival a “traitor”, Zipprick takes a different view.

“It would not occur to any fast-food chain to stuff us with 20 or 30 dishes full of chemical additives,” he says, referring to the El Bulli menu. The restaurant charges about £300 a head and opens for only six months a year, allowing the chef time to develop new dishes at his “laboratory” in Barcelona.

Britain’s Restaurant magazine has five times voted El Bulli the best restaurant in the world, but Zipprick calculates that a single visit accounts for 16% of an individual’s annual additive intake.

Some diners claim to have found it too much. Bill Buford, the American journalist, said his wife almost walked out after being served a wafer called “electric milk” that “incinerated her tongue”, while a student in his twenties was quoted (in a book about El Bulli) saying “the meal ... was an experience and art. I enjoyed it enormously and it made me vomit”.

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