Edible gelatin

This process sheet deals with a product whose use seems to date back to the 2nd century B.C., insofar as traces of gelatin glues, derived not only from pigs or oxen but also from fish, have been found in a pharaoh's tomb. In addition, Pliny the Elder states in his "Natural History" that the Romans were well aware of the special properties of gelatin, probably more as a glue than as a foodstuff. The history of bone glue dates back to the late 18th century, and its industrial manufacture to the 1820s. The historian tells us that the initial aim was to create a new food. It was exactly in 1681 that the idea of extracting gelatin from bones germinated in the brain of a man of genius, Denis Papin, who came up with the idea of applying heat treatment at a temperature of between 120 and 130°C, and therefore under pressure, in a pot known as an "autoclave" or "digester". However, this machine presented the risk of the safety valve opening unexpectedly, or even exploding! Another unforeseen problem was that high-temperature extraction led to the decomposition of gelatin, with a strong ammoniacal odor that made the finished product unpalatable, so the process was never industrialized. This was followed by a veritable jousting match between philanthropic chemists (Proust, Cadet de Vaux, Darcet père, Darcet fils) and gelatin's detractors, notably members of the Académie de Médecine, which lasted until 1830, when gelatin extracted from bones, in sheets or tablets, was distributed not only to the poor, but also to the bourgeoisie. In the end, Darcet fils's perseverance was rewarded, demonstrating, if proof were needed, that social barriers do not prevent transfers and exchanges .