Do we need to be trained to appreciate freshness?admin | November 10, 2013
To many people, the characteristic smell exuded by the linseed oil that their grandfather kept in his mancave for 35 years IS the aroma of olive oil. For them olive oil is supposed to smell like that, and it is exactly how they like it. I have always considered these people ‘misguided’. Surely, they must have learned to like rancidity. Perhaps a great-aunt from Omaha or Boise led them astray in their early childhood by force feeding them stuff out of the medicine cabinet. You know, the manky stuff with the yellowed label that needed carbon dating to validate the century in which it were made. But recent research using mice (Nankano et al. 2012) suggests that unsavory bullying from an uninformed, stodgey great-aunt might not be necessary to appreciate the delights of rancidity after all.
So here is how it went..
To provide a base-line, mice were presented with two bottles of the same non-oxidised olive oil in their feeding cage for three weeks. The amount consumed from each bottle was the same showing that the mice didn’t have a favourite restaurant strip.
But then one of the feeding bottles of fresh oil was replaced with another containing oxidised olive oil (left in a hot place in an open bottle for 3 weeks). The mice given the choice, consumed 10 times more of the oxidised oil than the fresh oil. The experiment was repeated using a heated refined olive oil. Same result – the mice chose to eat a lot more rancid oil than fresh oil.
Furthermore, the more the oil was oxidised (they made up blends of fresh and oxidised), the greater the preference for it. Mice that were anosmic (had no sense of smell) didn’t prefer one oil type over another suggesting that the aroma and flavour of the olive oil was the driving factor in preference.
Does this mean that rancid oil is the default for preference, and that appreciating fresh olive oil is a learned response? But leaving this important philosophical aside what I really want answered is – how the hell did the researchers identify anosmic mice (the ones without a sense of smell) from the non-anosmic mice? Did they put them under a bed doona and record which ones tried to escape?
Source: Nakano et al. (2012) Effects of aroma components from oxidised olive oil on preference. Bioscience, Biotechnology and Biochemistry. 77, 1166-1170.
You can read the article here: https://www.jstage.jst.go.jp/article/bbb/77/6/77_120861/_article