Let’s get this carbohydrate?

an appreciation blogpost for bread + quarantine exploration of kitchen biochemistry by Sangita Vasikaran

I saw this a while back:

Mood. I’ve always enjoyed baking and cooking, but during quarantine, I’ve chased this passion, and definitely have become associated with this pastime–so much so that my very traditional grandmother has named me (a 19 year old) “wife material” in Tamil. 

Patriarchy aside, that tweet really got me wondering…why is it that everyone is making bread of all things? 

@DanaSchwartzzz, I think you’re onto something with the word “instinct”. Carbs get this horrible rap in the media: this evil substance that pushes diets astray. But people who leave keto diets (a way of eating that is low in carbohydrates and high in fats + protein; known for its ability to produce rapid weight loss) remark that they simply crave the taste of sugar and bread. 

It makes sense why. Glucose, a simple carbohydrate, is literally lifeblood—glucose, a ring of 6 carbons, is the basic form of food we metabolize into ATP, or cellular energy(this is exactly what we learned of in the Krebs cycle!).  In bread, rice, and pasta, glucose forms into complex chains of starches that can be broken down over time, resulting in long-lasting energy. Sugar is glucose in one of its simplest forms: a dimer made of glucose and its cousin fructose;  thus it is one of the most immediate ways to get energy. Sugar tastes good because your brain loves to function. 

And humans have realized that! In almost all cuisines that I’ve come across, carbohydrates are universal parts of meals. From just a few ingredients: a flour, salt, some liquid–you can make such a wide spectrum of yum. Here are only some of my favorites homemade carbs in cuisine from quarantine: 

Only some of the homemade carbs I’ve made during quarantine…

I think about how much time I’ve spent in the kitchen as of these past 5 months, and honestly, I see baking and cooking as things I’ve used to fill the timespace of wet lab UROP work I usually engage in [funny enough, one of my graduate mentors works on SCOBY (Symbiotic Culture Of Bacteria and Yeast), especially that found in  kombucha pellicle]. In the kitchen, everyone is a scientist, guided by the biochemistry of carbs, fats, and proteins. If food science intrigues you, by the way, check out ESG’s Kitchen Chemistry course and Harvard’s annual Science + Cooking  seminar series. And declare Course 20, formerly food technology ;).

This is especially the case in breadmaking. Let’s dive in. 

If you’ve ever chewed a piece of bread for a long time, you’ll notice that it starts to taste sweet. Amylase, as well as other enzymes in your saliva, break down polymers of sugars (a.k.a starches) into their monomers. Some carbs have starches in chains (ex. wheat starch), some are stacked chains (ex. potato starch), and some are just complex formations (ex. cornstarch). Generally, things that taste sweeter faster do so because you can easily break down the starches. These are “simple” or “refined” carbs, like white rice and white bread. When a starch granule–the part of the grain that is harvested–has a germ or a bran, the enzymes (and your mouth, mechanically) have to work harder to break down the starch. Think of a sprouted whole grain bread, compared to Wonder bread. These parts of the grain often are denser in fiber and protein [things that support the growth of the grain embryo], as well, which can make you feel fuller faster–often giving them the reputation of being healthy.

Speaking of protein and chewing: the main framework of many wheat breads is gluten, made of two proteins: hydrophilic glutenin and hydrophobic gliadin.

They fit together to make a meshlike structure that can trap air and moisture, weaving together starch.

This structure is noticeable! Gluten doughs often respond to kneading by getting tougher and more cohesive (see the left panel above), whereas gluten-free doughs are more crumbly and often softer with more kneading. All that’s truly happening is a process called gelatinization: the dissolving of starch molecules into water. 

Celiac disease is the body being ‘allergic’ to parts of this very gluten network, and thus gluten free flours, like oat, chickpea, or rice are often used. On the other end, bagels and crusty breads are often made with flours with higher gluten content, to promote their hole-y structure, which gives these baked goods their chewiness. This is called bread flour; vice versa, when you want an easily digestible, “melt in your mouth” chew, you use pastry flour (think cakes), with very low gluten content. Mixing gluten-free flours with gluten doughs can disrupt network development, leading to a softer dough with familiar texture; for example, my mother has started mixing in a spoonful of almond flour along with our traditional atta (stone ground wheat) flour for tender rotis thanks to our experiments 🙂

You can also even buy pure wheat gluten, and add it into your heart’s desire! Pure wheat gluten is very high in protein, as this is all it is– and it is otherwise known as seitan, which is often used as a meat substitute. 

My homemade attempt at plant-based deli sausage seitan, made from pure gluten.

So, as we can see, gluten–this net of proteins–is what is responsible for the major texture notes in bread. Crumb [how open or tight the hole structure is] and chew [texture while eating]  are two terms that are important attributes that fancy breadmakers (you included now too!) use.

A range of crumbs, courtesy of my own creations! From tight crumb on the left in moist, buttered cornbread, to open crumb in the middle crusty breads, and virtually no crumb in the dense biscotti on the right.

Some chews in picture form of my own making as well: soft, pillowy naans and Hawaiian rolls on the left, to more crispy, cakelike, rich, Belgian waffles, to craggly soup bread on the right.

There are a number of variables that can even further affect gluten development, and thus texture! Fats promote moisture retention during the baking process and can bake into a crust or flaky layers; sugar and salt disrupt network development and can speed up or slow down fermentation by yeast. If one ever has a question about substitutions or inclusions, chances are that someone has played with a similar idea and actually experimented. The most wonderful thing I’ve picked up from the questions I’ve Googled is that a whole community of tinkerers in the kitchen exists. Blogs, Youtube videos, and  r/BreadIt are only a few of the ways I’ve learned most of what I’m conveying to you in this piece: knowledge is all around us.

I hope in this post you’ve been able to look through a tiny window to appreciate just one facet of the complex engineering behind the food that surrounds us all–it’s definitely something that sparked a childlike curiosity within me. This tangible application of biochemistry is something that has personally taught me a lot during these past months at home. I’m extremely grateful to have the ability to experiment with ingredients and concoctions of recipes, as well as family to share it with at the moment. I think that kitchen biochemistry is biomaking in its essence;  in many ways, this thinking, doing, and making the world a little happier in the process,  is how I want to feel when I’m working on projects with our group back at MIT. 

The kitchen may not just be my BioMakerSpace substitute for quarantine–through learning so much about nutrition and how meaningful it is to humans,  I’ve become interested in exploring potential future careers in food biotechnology: in other words, biomaking, applied broadly from cellular agriculture to GMOs. We are only on the cusp of these technologies’ frontiers and impacts, and man, I’m hungry for it. 

Happy researching–I mean, bread baking!

References:

https://www.reddit.com/r/Breadit/

https://www.nature.com/articles/s41538-019-0040-1

https://www.bakeinfo.co.nz/Facts/Gluten/What-role-does-gluten-play-in-bread-making-

3 Comments on “Let’s get this carbohydrate?

  1. Hello there! This is my first visit to your blog! We are a collection of volunteers and starting a new initiative in a community in the same niche. Your blog provided us useful information to work on. You have done a marvellous job!

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