By Andrew Lee '21
How does a cucumber become a pickle?
Many of us know by now that pickles are actually just cucumbers, except more processed. But, what is the actual process that turns a cucumber into a pickle?
Unsurprisingly, this process is called pickling, which is a common method to preserve the life of fruits and vegetables. This process was first practiced around 2400 BCE, and up until the beginning of artificial refrigeration in the mid-1750s, it was a good way to preserve food items, especially for people like sailors that had to go for long stretches of time with limited food supply. Although the process originally was meant for food preservation, people began pickling foods because they liked the taste. For example, foods like sauerkraut, and kimchi are made of pickled cabbage, which gives them their unique flavor.
There are several variations on the pickling process, using slightly varying methods to achieve different results. The type we will be talking about today is called brine fermentation.
The process of brine fermentation is relatively straightforward. To make cucumber pickles, you will want to have brine with around 3.5% to 5.0% salt concentration. Submerging the cucumbers in the brine solution will encourage the reproduction of lactic acid bacteria, which then begin the process of lactic acid fermentation.
Lactic acid fermentation is a type of fermentation, which itself is a pathway within cellular respiration. However, while cellular respiration normally oxidizes organic compounds into carbon dioxide, lactic acid fermentation only goes halfway. First, glycolysis (glyco- refers to sugar, and -lysis refers to breaking) turns glucose into two three-carbon molecules of pyruvate, which are usually sent to the mitochondria to produce the bulk of the energy output of cellular respiration. However, lactic acid bacteria do not have mitochondria, so they carry out lactic acid fermentation instead, converting pyruvate to lactic acid.
When put in the brine, lactic acid bacteria are able to thrive, taking glucose from the sugars in cucumbers and converting it to lactic acid. This lactic acid gives the pickles their characteristic sour smell and flavor. As this lactic acid accumulates, it makes the brine more and more acidic, killing off other microorganisms and effectively sanitizing the pickles, lengthening its shelf life. Plus, the lactic acid, when consumed, is an excellent source of energy for the body. Normally, humans are unable to digest cellulose, but now that the lactic acid bacteria have gone and broken it down into lactic acid, the body can indirectly tap into the energy in the cellulose that it otherwise would not have been able to access.
After leaving the cucumbers in brine for a while, you will find yourself with a fresh new batch of pickles. Cucumber pickles made this way are often called lacto-fermented pickles, and they have tremendous health benefits. Pickles have lots of probiotics, which carry the same benefits of adding microbe diversity in the gut that foods like yogurt or cheese. Plus, although it might sound a little repulsive, pickle juice contains tons of salts and electrolytes that some athletes swear by as a post-workout drink.
We can see now that yes, pickles are just more processed cucumbers. But, now that we’ve looked a little deeper into how they’re made, it does go to show how easy it is to gloss over a whole world—or in this case, a whole bacterial culture—of things that happen right beneath our eyes.
Sources:
https://www.makesauerkraut.com/fermented-pickles/
https://www.foodandwine.com/vegetables/pickled-vegetables/science-vinegar-pickles-explained
Kommentarer