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Breaking Food Down

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What is food?

The Merriam-Webster Dictionary entry says “Something that nourishes, sustains, or supplies.”

How beautiful. That statement captures much of the emotion and feeling surrounding food, yet it’s only part of the full definition.

So where does food begin?

As with most big questions, it depends who you ask. Let’s start down the reductive reasoning road: a young child might say food starts when a parent sets a plate in front of them. A chef might use her well-honed knives and skills to carefully craft food from hand-selected farm-fresh ingredients. The farmer, in turn, knows food consists of the animals and crops he raises.

An ecologist would stress interconnectedness, webs and cycles that show the flow of food nutrients and energy through different populations. Biologists break foods down further, stripping starches and proteins down to simple sugars and amino acids. Chemists (like me!) take the next leap, deconstructing those food components into energy released from the making and breaking of atomic bonds (since we’re already at the atomic level, we should mention that lots of folks – biochemists, engineers, organic chemists, materials scientists – try to build these food molecules from simpler stuff).

Original Image U. Huddersfield.

Eat up.

Further along, astronomers and physicists look to the sun, the giant ball of fusion energy constantly sending photons, tiny packets of light, in our direction. Plants and microorganisms use these photons to drive food formation. Could our nourishment have roots beyond the stars? Maybe; science traditionally leaves these questions to philosophers and religious authorities.

Let’s come back down to Earth, where I’ll stake my claim for this Food Matters group venture. For me, food begins when molecules you can’t eat – nitrogen gas, carbon dioxide gas, certain salts and minerals – turn into something you could eat. To achieve this feat, one must drill down to the level of enzymes, biology’s tiny chemistry factories.

The inner workings of just one enzyme could easily fill a series of posts, so I won’t dive too deeply here. By greatly speeding up certain reactions, enzymes turn metabolically inert substances into the starting materials for sugars and proteins. Their “fuel” comes from many places: heat and light from the sun, electrons flowing from metals, other reactions, and small differences in pH or concentration. Enzymatic reactions, which happen billions of times a day all around us, go largely unnoticed. Yet they make everything you put in your belly, from apples to zucchini.

Once you’ve seen food at the atomic scale, it’s tough to go back. Savory steaks? Muscle tissue, seared to perfection. Yogurt? An active stew of bacteria pre-digesting milk products. Nuts? Full of monounsaturated fats, which have an olefinic “kink” in their chains, meaning they can’t pack together as well as saturated fats. Not to mention all those vitamins, which have complex structures rivaling pharmaceutical molecules.

Remember that dictionary definition at the top? Here’s the rest: “Food: Material consisting essentially of protein, carbohydrates, and fat used in the body of an organism to sustain growth, repair, and vital processes and to furnish energy. Inorganic substances absorbed by plants in gaseous form or water solution.

Let’s explore this delicious molecular playground together. I hope to convince you that food begins and ends with chemistry.

See Arr Oh About the Author: Workaday synthetic chemist interested in everything. Find See Arr Oh at Follow on Twitter @seearroh.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. jhmaroneyjr 11:23 am 09/8/2013

    Dear Arr:

    I have great respect for your discipline but maybe less for your application of it. I hope you know that for 99.999% of us, food is not “something” that nourishes and neither does food “begin and end with chemistry.” I do not imagine you can fathom why for the 99.999% the marriage of organic with GE is abominable. I am an organic farmer and I eat only organically raised “natural” food, consummately rich in variety and coming just as it does from the ground (I am also a vegetarian) wondrously nourishing. I do not concern myself with food’s constituent elements; why need I? As I read the various writers posting on Scientific American’s new Food Matters blog, I cannot escape the anxiety that if scientists are given any more dominion over what constitutes food, manufactures will hasten the arrival on our plates of “something” that fits your descriptors, something efficient and comprehensive like blocks of compressed nutrients meeting all my “needs”. I am gratefully too old to think your food will arrive in my lifetime but I shudder for my children.

    James H. Maroney, Jr.
    Masters in Environmental Law & Policy, VLS ’12

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  2. 2. Kevbonham 12:30 pm 09/10/2013

    @ jhmaroneyjr: I think your comment perfectly illustrates one of the major disconnects between scientists and consumers that a lot of us are going to be talking about on the blog – that is, the idea that there is an easy definition of “natural” vs “unnatural” that is somehow meaningful beyond our perceptions.

    Even if you eat solely organic, locally grown produce, you are consuming the product of 10,000 years of human manipulation. That produce is decidedly unnatural (as evidenced by the amount of care required to cultivate it). Many of the most deadly toxins are completely natural. Many molecules that exist only because humans created them in a lab are safer or more efficacious than analogs found in nature (see: aspirin vs salicylic acid).

    You say, “I do not concern myself with food’s constituent elements; why need I?” You needn’t. Presumably you live in a first-world country and can afford to pay the premium on organic food, your government enforces food-standards regulation to prevent unsafe foods from being sold etc. You’re free to remain ignorant of the chemical make-up of your food, and you’re free to not read the blog (about the science of food, which yes includes its chemistry).

    But I think your assertion that 99.999% of people, especially people reading a food blog on a website dedicated to science, will chose to remain ignorant and have no curiosity about what exactly is in their food is pretty off the mark. And to scold a chemist because he thinks about (and is willing to take the time to share his knowledge about) the chemistry of food is absurd.

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