Sweeter than honey, more bitter than gall, saltier than my tears... for most of humanity's time on earth, these have been examples of poetic license, self-consciously exaggerated similes - but no longer, thanks in part to Dr. Kikunae Ikeda. This week in 1908, he made a discovery that would change taste forever.
Like many of his countrymen, Dr. Ikeda was interested in aspects of Japanese life not explained by Western science - in this case, the universal fondness for kombu, a seaweed prized for meaty, satisfying soups. What was it in kombu that imparted such general, but particular, deliciousness? Ikeda went through the tedious multiple steps of chemical purification until he was left with a brown crystalline substance that displayed the unique taste: glutamic acid.
Two results came out of Ikeda's discovery: the first is that humans have a extra taste dimension beyond the classical foursome of sweet, bitter, salt, and sour. Borrowing the Japanese word for "delicious," Ikeda called it umami - that meaty flavor present in soy sauce, cheese, meat, mushrooms, and any edible protein. The second was that this newly-defined taste sensation could be elicited by a single chemical, an amino acid that Ikeda synthesized in its current, universal form: monosodium glutamate. No longer would it be necessary to harvest seaweed from the chilly waters off Hokkaido; umami could be available to the world in a few shakes of powder.
Our naked, hungry ancestors spent their lives in a constant quest for intense nourishment. Bitter herbs and tubers are all very well, but an active primate with a big, energy-demanding brain will always prefer more concentrated sources of calories: sugars, fats, meat. Chemically, these have no perceptible flavors, but when we eat them, the resulting "cleavage products" produce the sweet and umami sensations we still crave, though we no longer have to cross miles of savannah to find them.
Finding and catching your own food is hard work, physically and mentally – modern hunter-gatherers must hone their skills over a longer time than it takes to train a brain surgeon. To motivate such effort requires a powerful spur – and we all know how powerful hunger can be – with an equally powerful payoff: yum!
Salt, sweet and umami are signals of a successful search for food - rewards that encapsulate the greater good of continued survival in a harsh environment. Our response to them, therefore, is not rational, but primitive and intense: yummy things are good. We must have them.
Unfortunately, thanks to Ikeda and his fellow scientists, yumminess is now a separate, artificial element that can be added to any basic foodstock, however bland or even distasteful. Fructose makes colored water intensely desirable: when cola makers switched to it, we drank more of their product. Salt, once so rare as to be used in religious rituals, now enlivens all prepared foods, from soups to breads. And monosodium glutamate, usually hiding under the name of "spices," or "natural flavorings," gives salad dressing, sauces, potato chips, and crackers a mouth-filling goodness that keeps us asking for more… and more.
It's not that these substances are intrinsically bad for us (as always, in moderation); the problem is psychological. Because we are attuned to respond to the stimulus, not the substance, of what we eat, industry naturally offers us more stimulus. We, in turn, consume sweetened drinks, salty food and umami-flavored fats with avidity, because our brains tell us we have found something rare and wonderful. We eat in a day what our bodies expect us to have sought out, with effort, during a week.
That's our problem - the problem for industry is that human response to repeated stimulus tends to decline over time. To produce the same urge to buy, manufacturers need to add ever-greater amounts of what we crave and offer them in ever-larger portions. Thus the world spins on: fatter people, dancing to louder music. It might be no bad thing to get back in the boat and look for some seaweed.
If you like these stories of fallible human nature, you will find one every day on my other site, (http://www.bozosapiens.blogspot.com). See you there.
