WEBVTT - How Can Microorganisms Make Food Delicious and Nutritious?

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<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff

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<v Speaker 1>Lauren Volgebon Here. You might think that you try to

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<v Speaker 1>avoid microorganisms in your food because bacteria and fungi cause

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<v Speaker 1>food to spoil. But the truth is we wouldn't have

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<v Speaker 1>a lot of the world's favorite foods and beverages like coffee, chocolate, vanilla, cheese, bread, beer,

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<v Speaker 1>and cured meats, just to name a few, without fermentation,

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<v Speaker 1>which involves the intentional use of microorganisms to transform food.

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<v Speaker 1>The line between spoiling and fermentation is a muddy one,

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<v Speaker 1>but a distinction humans have been fuzzing with for millennia. Generally,

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<v Speaker 1>when we say that food has spoiled, what we technically

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<v Speaker 1>mean is that microbes have started eating it before we've

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<v Speaker 1>had a chance to, and that they've made the texture

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<v Speaker 1>and or flavor unpleasant to us. And if those microbes

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<v Speaker 1>are pathogenic, eating that food could even make us sick.

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<v Speaker 1>When we ferment food, we're employing helpful, nonpathogenic microbes to

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<v Speaker 1>spoil it on purpose before harmful microbes can get to it.

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<v Speaker 1>For the article, this episode is based on How Stuff Work.

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<v Speaker 1>Spoke with sand Or Cats, a teacher and author of

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<v Speaker 1>several books about fermentation. He said, what microbiology has illuminated

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<v Speaker 1>is that all the plants and animal products that make

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<v Speaker 1>up our food are inevitably populated by a diversity of microorganisms.

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<v Speaker 1>Fermentation involves encouraging the growth of some microorganisms, ones that

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<v Speaker 1>make our food more stable, more delicious, more nutritious, safer,

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<v Speaker 1>less toxic or alcoholic, and thereby prevent the growth of

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<v Speaker 1>the ones that can decompose our food or make us sick.

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<v Speaker 1>Every known culinary tradition in the world uses fermentation in

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<v Speaker 1>some way or another. Humans began using fermentation to brew beer,

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<v Speaker 1>preserve food, and make their food tasty, and render toxic

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<v Speaker 1>things edible millennia before Louis Pasteur proved that living cells

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<v Speaker 1>were responsible for fermentation. Akatz said the oldest examples of

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<v Speaker 1>fermentation in the archaeological record are from about ten thousand

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<v Speaker 1>years ago in China, though I would argue that tells

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<v Speaker 1>us more about the history of pottery than the history

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<v Speaker 1>of fermentation. Presumably, the cultural practice of fermentation is older

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<v Speaker 1>than that using pits of the ground, gourds, animal membranes, wood,

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<v Speaker 1>or other biodegradable materials. It's no surprise that fermentation can

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<v Speaker 1>be traced back to around the same time as humans

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<v Speaker 1>began developing communities around agriculture. In order for it to

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<v Speaker 1>make sense for us to invest all our time and

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<v Speaker 1>energy into growing plants and livestock for food instead of

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<v Speaker 1>hunting and gathering, humans would have had to come up

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<v Speaker 1>with a strategy for storing and preserving food so that

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<v Speaker 1>the harvest of a few weeks could last the community

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<v Speaker 1>many months. Also, basically every culture in the world has

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<v Speaker 1>figured out how to ferment sugars into alcohol. It's possible

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<v Speaker 1>that our primate ancestors understood the party inducing effects of

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<v Speaker 1>eating a bunch of fermented fruit that they found on

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<v Speaker 1>the ground. It helps that the yeasts that turn sugars

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<v Speaker 1>into alcohol grow wild in the air and on the

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<v Speaker 1>skins of many fruit. All humans had to do was

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<v Speaker 1>figure out how to do this on purpose. The word

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<v Speaker 1>ferment comes from the Latin word for boiling or rising,

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<v Speaker 1>which makes perfect sense if you've ever seen beer brewing

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<v Speaker 1>or bread dough rising. The bubbles and beer and pockets

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<v Speaker 1>of air and bread both come from the action of

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<v Speaker 1>yeasts living. The applied science of zymology is the study

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<v Speaker 1>of how microorganisms ferment these stuff around us. Oh, what

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<v Speaker 1>the biochemical processes are which specific organisms are doing it,

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<v Speaker 1>and how this works all over the world, including in

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<v Speaker 1>our foods. There are three base types of fermentation that

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<v Speaker 1>can happen in the foods and drinks we enjoy every day.

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<v Speaker 1>Alcoholic fermentation has been a fan favorite for millennia. It

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<v Speaker 1>uses yeasts to convert sugars in plants like grains or

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<v Speaker 1>fruit into ethanol, carbon dioxide, and other byproducts, some of

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<v Speaker 1>which we experience as flavors. Humans invented alcoholic beverages before

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<v Speaker 1>we invented the wheel. Then there's acetic acid fermentation, which

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<v Speaker 1>happens after yeasts finish their alcoholic fermentation and acetic acid

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<v Speaker 1>bacteria take over. These bacteria ferment sugars and ethanol into acids,

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<v Speaker 1>are resulting in things like vinegar and kombucha. Last, but

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<v Speaker 1>not least, there's lactic acid fermentation, which is the microbial

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<v Speaker 1>magic behind so many of our favorite foods, from sour

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<v Speaker 1>dough bread to kimchi to yogurt, plus many types of cheese.

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<v Speaker 1>Lactic acid bacteria convert simple carbohydrates into lactic acid, a

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<v Speaker 1>process that turns sweet things sour, which is what gives

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<v Speaker 1>all of the above foods their characteristic kick a note

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<v Speaker 1>that often the fermented foods we eat rely on more

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<v Speaker 1>than one of these processes. Some beers are flavored with

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<v Speaker 1>help from lactic acid bacteria. Pickles can be made either

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<v Speaker 1>with lactic acid bacteria or vinegar, or a combination of both,

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<v Speaker 1>and things like chocolate and coffee get some of their

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<v Speaker 1>characteristic flavor from a combination of all three. But these

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<v Speaker 1>processes don't just make food tart or tasty or alcoholic.

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<v Speaker 1>They also make them last longer. You know, cheese stays

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<v Speaker 1>good longer than milk. But part of what's so cool

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<v Speaker 1>about our ancestors using fermentation on food is that, thousands

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<v Speaker 1>of years before we understood what microbes or nutrients are,

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<v Speaker 1>we were using microbes to unlock nutrients. The microorganisms that

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<v Speaker 1>ferment our food essentially break down things like carbohydrates, proteins,

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<v Speaker 1>and chemical bonds in our food before we eat it,

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<v Speaker 1>in some cases, making it more easily digested or its

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<v Speaker 1>nutrients more bioavailable. That's why someone with the lactose intolerance

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<v Speaker 1>might be able to eat in aged cheese with no issue.

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<v Speaker 1>The lactose or milk sugar will have been almost entirely

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<v Speaker 1>broken down by bacteria. During the aging process. Fermentation also

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<v Speaker 1>generates additional bee vitamins in many foods and cave vitamins

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<v Speaker 1>in some. Furthermore, some foods can only be made edible

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<v Speaker 1>at all through fermentation. The microorganisms take potentially toxic to

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<v Speaker 1>us compounds and digest them into harmless or even beneficial forms,

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<v Speaker 1>rendering foods that could otherwise be poisonous or irritating safe

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<v Speaker 1>to eat. One example of this can be found in

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<v Speaker 1>cassava tubers. They contain high levels of cyanide when they're

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<v Speaker 1>harvested and require fermentation to make them safe to eat.

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<v Speaker 1>One popular health claim made about some fermented foods is

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<v Speaker 1>that they contain probiotics, which are live microorganisms that are

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<v Speaker 1>supposed to help our digestive systems and or our gut

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<v Speaker 1>microbiome function better. Unfortunately, science hasn't been able to prove

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<v Speaker 1>those claims yet. Our bodies are complicated and more research

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<v Speaker 1>is necessary there. As with any food or drink, we

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<v Speaker 1>hear brain stuff think that you should consume fermented products

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<v Speaker 1>if you like them. Katz said certain ferments, such as

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<v Speaker 1>strong cheeses, are edgy, and that some people find them

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<v Speaker 1>compellingly delicious, while others think that they're disgusting and are

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<v Speaker 1>reminded of decomposition and death. Science offers us no sharp

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<v Speaker 1>dividing line between fermentation and spoilage. In most cases, it's obvious,

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<v Speaker 1>but in certain cases it's culturally determined and subjective. Today's

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<v Speaker 1>episode is based on the article food Fermentation How microorganisms

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<v Speaker 1>make Food Delicious on HowStuffWorks dot com, written by Jesselynshields.

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<v Speaker 1>For lots more about how food fermentation works, check out

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<v Speaker 1>my other podcast Saver brain Stuff is production of iHeartRadio

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<v Speaker 1>and partnership with how stuffworks dot Com, and is produced

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<v Speaker 1>by Tyler klang A. Four more podcasts my heart Radio,

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