The authors says that the findings indicate that our ancestors had an intrinsic preference for cooked meals, and most likely had a preference for cooked foods before controlled fire emerged. According to the team, since that happened between one million and 1.6 million years ago, hominids probably began to cook their food not long thereafter. "Given our evidence, early hominids would have already had a preference for the taste of cooked foods, so it is more likely that cooking may have emerged soon after the control of fire," Discovery News quoted lead author Victoria Wobber, as saying.
To find out whether prehistoric hominids might have rapidly used fire to cook their food because it improved taste or texture, Wobber, a Harvard University anthropologist, with colleagues Brian Hare and Richard Wrangham, conducted multiple food tests using captive chimpanzee, bonobo, gorilla and orangutan populations from facilities in the United States, Europe and the Congo Republic.
In the first test, a group of chimps was offered a choice between raw and cooked carrots, sweet potatoes and white potatoes. The second test offered apes of each kind either cooked or raw cubed, mashed or grated carrots, since carrots came out as a chimp favorite in the first experiment.
For the third test, the apes were offered a choice between cooked or raw apple and cooked or raw beef.
In the end, the researchers gave the Congo chimps, which had never eaten cooked food of any kind, a choice between cooked and raw beef.
Results showed hat the entire ape tasters preferred cooked over raw foods, with the exception of white potatoes and apples.
In those instances, they demonstrated no preference between cooked or raw, perhaps because these items are easily chewed raw, and cooking them does not enhance their sweetness.
During the second experiment, designed to compare food textures, the apes turned their noses up to raw, grated carrots and showed that they strongly preferred the vegetable cooked and mashed.
"It is likely that the properties present in cooked foods are preferable to most mammals, as rats and cats have both been shown to prefer cooked food or cooked taste," Wobber said.
The authors said that the fact that chimps had tasted cooked food before, may have influenced the outcome, as well as the novelty of cooked food could also have affected the results.