How Can Microorganisms Make Food Delicious and Nutritious?

Some microbes make food spoil, but others help preserve it -- and even create our favorite flavors and effects, from cheese to chocolate to chardonay. Learn more about food fermentation in this episode of BrainStuff, based on this article: https://recipes.howstuffworks.com/food-fermentation.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff
Lauren Volgebon Here. You might think that you try to
avoid microorganisms in your food because bacteria and fungi cause
food to spoil. But the truth is we wouldn't have
a lot of the world's favorite foods and beverages like coffee, chocolate, vanilla, cheese, bread, beer,

(00:26):
and cured meats, just to name a few, without fermentation,
which involves the intentional use of microorganisms to transform food.
The line between spoiling and fermentation is a muddy one,
but a distinction humans have been fuzzing with for millennia. Generally,
when we say that food has spoiled, what we technically

(00:48):
mean is that microbes have started eating it before we've
had a chance to, and that they've made the texture
and or flavor unpleasant to us. And if those microbes
are pathogenic, eating that food could even make us sick.
When we ferment food, we're employing helpful, nonpathogenic microbes to
spoil it on purpose before harmful microbes can get to it.

(01:13):
For the article, this episode is based on How Stuff Work.
Spoke with sand Or Cats, a teacher and author of
several books about fermentation. He said, what microbiology has illuminated
is that all the plants and animal products that make
up our food are inevitably populated by a diversity of microorganisms.
Fermentation involves encouraging the growth of some microorganisms, ones that

(01:37):
make our food more stable, more delicious, more nutritious, safer,
less toxic or alcoholic, and thereby prevent the growth of
the ones that can decompose our food or make us sick.
Every known culinary tradition in the world uses fermentation in
some way or another. Humans began using fermentation to brew beer,

(01:59):
preserve food, and make their food tasty, and render toxic
things edible millennia before Louis Pasteur proved that living cells
were responsible for fermentation. Akatz said the oldest examples of
fermentation in the archaeological record are from about ten thousand
years ago in China, though I would argue that tells

(02:19):
us more about the history of pottery than the history
of fermentation. Presumably, the cultural practice of fermentation is older
than that using pits of the ground, gourds, animal membranes, wood,
or other biodegradable materials. It's no surprise that fermentation can
be traced back to around the same time as humans
began developing communities around agriculture. In order for it to

(02:43):
make sense for us to invest all our time and
energy into growing plants and livestock for food instead of
hunting and gathering, humans would have had to come up
with a strategy for storing and preserving food so that
the harvest of a few weeks could last the community
many months. Also, basically every culture in the world has

(03:03):
figured out how to ferment sugars into alcohol. It's possible
that our primate ancestors understood the party inducing effects of
eating a bunch of fermented fruit that they found on
the ground. It helps that the yeasts that turn sugars
into alcohol grow wild in the air and on the
skins of many fruit. All humans had to do was
figure out how to do this on purpose. The word

(03:27):
ferment comes from the Latin word for boiling or rising,
which makes perfect sense if you've ever seen beer brewing
or bread dough rising. The bubbles and beer and pockets
of air and bread both come from the action of
yeasts living. The applied science of zymology is the study
of how microorganisms ferment these stuff around us. Oh, what

(03:49):
the biochemical processes are which specific organisms are doing it,
and how this works all over the world, including in
our foods. There are three base types of fermentation that
can happen in the foods and drinks we enjoy every day.
Alcoholic fermentation has been a fan favorite for millennia. It
uses yeasts to convert sugars in plants like grains or

(04:12):
fruit into ethanol, carbon dioxide, and other byproducts, some of
which we experience as flavors. Humans invented alcoholic beverages before
we invented the wheel. Then there's acetic acid fermentation, which
happens after yeasts finish their alcoholic fermentation and acetic acid

(04:32):
bacteria take over. These bacteria ferment sugars and ethanol into acids,
are resulting in things like vinegar and kombucha. Last, but
not least, there's lactic acid fermentation, which is the microbial
magic behind so many of our favorite foods, from sour
dough bread to kimchi to yogurt, plus many types of cheese.

(04:56):
Lactic acid bacteria convert simple carbohydrates into lactic acid, a
process that turns sweet things sour, which is what gives
all of the above foods their characteristic kick a note
that often the fermented foods we eat rely on more
than one of these processes. Some beers are flavored with

(05:16):
help from lactic acid bacteria. Pickles can be made either
with lactic acid bacteria or vinegar, or a combination of both,
and things like chocolate and coffee get some of their
characteristic flavor from a combination of all three. But these
processes don't just make food tart or tasty or alcoholic.

(05:39):
They also make them last longer. You know, cheese stays
good longer than milk. But part of what's so cool
about our ancestors using fermentation on food is that, thousands
of years before we understood what microbes or nutrients are,
we were using microbes to unlock nutrients. The microorganisms that

(06:00):
ferment our food essentially break down things like carbohydrates, proteins,
and chemical bonds in our food before we eat it,
in some cases, making it more easily digested or its
nutrients more bioavailable. That's why someone with the lactose intolerance
might be able to eat in aged cheese with no issue.
The lactose or milk sugar will have been almost entirely

(06:23):
broken down by bacteria. During the aging process. Fermentation also
generates additional bee vitamins in many foods and cave vitamins
in some. Furthermore, some foods can only be made edible
at all through fermentation. The microorganisms take potentially toxic to
us compounds and digest them into harmless or even beneficial forms,

(06:45):
rendering foods that could otherwise be poisonous or irritating safe
to eat. One example of this can be found in
cassava tubers. They contain high levels of cyanide when they're
harvested and require fermentation to make them safe to eat.
One popular health claim made about some fermented foods is
that they contain probiotics, which are live microorganisms that are

(07:07):
supposed to help our digestive systems and or our gut
microbiome function better. Unfortunately, science hasn't been able to prove
those claims yet. Our bodies are complicated and more research
is necessary there. As with any food or drink, we
hear brain stuff think that you should consume fermented products
if you like them. Katz said certain ferments, such as

(07:30):
strong cheeses, are edgy, and that some people find them
compellingly delicious, while others think that they're disgusting and are
reminded of decomposition and death. Science offers us no sharp
dividing line between fermentation and spoilage. In most cases, it's obvious,
but in certain cases it's culturally determined and subjective. Today's

(07:56):
episode is based on the article food Fermentation How microorganisms
make Food Delicious on HowStuffWorks dot com, written by Jesselynshields.
For lots more about how food fermentation works, check out
my other podcast Saver brain Stuff is production of iHeartRadio
and partnership with how stuffworks dot Com, and is produced
by Tyler klang A. Four more podcasts my heart Radio,
visit the iHeartRadio app, Apple Podcasts, or wherever you listen

(08:19):
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