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Spherification and Edible Water Spheres

4/24/2017

In the culinary world, spherification is the process of encasing a liquid in a gel membrane using sodium alginate and calcium chloride. These little spheres are completely edible, and are used in boba tea, synthetic caviar, and almost any other liquid you’d want to store in such a way.

Chemistry of Spherification

Sodium alginate (C6H9NaO7) is a chemical that’s extracted from brown seaweed to be used in many different kinds of foods. For example, it acts as a stabilizer for ice cream and yoghurt, and is a thickener for salad dressings and canned products. When it’s in the presence of calcium it forms a gel that requires no heat to take shape!

Calcium Chloride (CaCl) is a salt that acts as a preserving agent in some foods. It’s what makes pickles and other similar foods taste salty without adding actual table salt. It can also be used to tenderize meat and make fruits and vegetables more firm. This chemical assists in creating a gel membrane around liquid.

When sodium alginate (dissolved in a liquid) meets calcium chloride (dissolved in water), a chemical reaction happens! Just like when oil is mixed with water, little spheres start to form in the solution, trapping the liquid inside. It only takes a few seconds for the calcium solution to cause the outer layer of the alginate liquid to form a thin and flexible skin.

Water Spheres

Each year, billions of plastic bottles are used in the United States. Only a small percentage of these bottles are recycled, wasting plastic and destroying the environment if they’re littered outside. Thanks to the process of spherification, we can begin to use larger spheres of water to replace plastic water bottles!

Because the membrane around a sphere is very thin, it can’t hold as much water as a plastic water bottle could. Instead, when using the spheres to replace a water bottle, you’d need to have multiple spheres ready to drink. One company in the UK has started marketing their own version of edible water “bottles” called the Ooho. There are actually two layers of gel in the Ooho before you reach the water inside. The outermost layer is meant to be peeled off, like a banana peel, to protect the actual water from contamination.

Make Your Own Edible Water Bottle

To make your own water sphere, you’ll need just a few ingredients, which are easy to find online. We’ll use calcium lactate instead of calcium chloride in this activity, because we don’t want our water to taste salty!

What you need:

1 gram (0.04 ounces) of sodium alginate
5 grams (0.18 ounces) of calcium lactate
Three mixing bowls
Water
Hand mixer
Wooden spoon
Slotted spoon
A spoon with an exaggerated curve

Step 1: Fill one of the bowls with one cup of drinking water and add in the sodium alginate. Mix thoroughly with the hand mixer and let sit for 15 minutes to get rid of all the air bubbles.

Step 2: In another bowl with 4 cups of water, add in the calcium lactate and stir well using the wooden spoon. Make sure everything is dissolved.

Step 3: Take your curved spoon and scoop up the sodium alginate solution and gently place it into the calcium lactate bath. It will start to form a sphere immediately. Repeat this step as many times as you like, just make sure not to add too many to prevent the bowl from getting crowded.

Step 4: Using the wooden spoon, stir the bath with the spheres very gently for about three minutes to help the gel membrane fully form.

Step 5: Use the slotted spoon to scoop up the water spheres and place them in the last bowl, filled with regular water. This will stop the reaction and prevent the gel from getting too thick.

Now you can pop your water “bottles” into your mouth for a nice drink of water! The gel is completely edible, but if you don’t like the texture you can throw it in the compost and it will decompose just like the skin of a fruit.

References:

Baguley, Richard. “Appliance Science Experiments: Creating edible water spheres”. CNET - July 2015. Accessed April 21, 2017.
<https://www.cnet.com/news/appliance-science-experiments-creating-edible-water-spheres/>

https://food-hacks.wonderhowto.com/how-to/make-water-bottles-you-can-eat-0154909/

Image Credits:

Lastras, Javier. “Spherification of Green Tea”. Released into the public domain under the Creative Commons Attribution 2.0 Generic license. Uploaded on 4/22/17 from wikimedia.org

Arnold, Karen. “Salt in the Hand”. Released into the public domain. Uploaded on 4/22/17 from publicdomainpictures.net

Rondeau, Charles. “Plastic Bottles”. Released into the public domain. Uploaded on 4/22/17 from publicdomainpictures.net

Hodan, George. “Water Drops on a Spoon”. Released into the public domain. Uploaded on 4/22/17 from publicdomainpictures.net

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Baby Birds and How They Hatch

4/17/2017

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Spring is here, and that means birds all over the world are getting ready to make a nest and lay their eggs! You might have seen a nest in a tree, or perhaps you’ve participated in a spring egg hunt to find colored eggs hidden outside. Before a baby chicken grows in an egg, you can harvest the eggs to be cooked and eaten!

But when an egg is fertilized, a baby bird grows inside until it’s big and strong enough to hatch and meet the world!

Anatomy of an Egg

The first part of an egg that you see is the shell. Egg shells have very diverse appearances, depending on the type of bird that laid it. Chicken eggs, for example, are white or brown. The American robin lays bright blue eggs with brown speckles. The surface of the shell is bumpy and grainy, due to the thousands of little pores that allow air and moisture into the egg. There’s also an outer coating on the shell, called the cuticle, that keeps out dust and bacteria to keep the baby bird healthy as it develops.

In between the eggshell and the egg white, there are two membranes (inner and outer) that provide more defense against bacteria that may have slipped in through the shell. These layers are made of keratin; the same protein that makes up human hair.

An air space forms when the insides of the egg cool and contract after it’s laid. The air cell usually rests between the outer and inner membranes at the egg’s larger end, and it accounts for the crater you often see if you’ve eaten a hard-boiled egg. This air cell grows larger as an egg ages.

The egg white is also known as the albumen, which comes from albus, the Latin word for “white.” Four alternating layers of thick and thin albumen contain approximately 40 different proteins, the main components of the egg white in addition to water.

The next component of an egg is the yolk. Contrary to popular belief, the yolk is not what develops into a baby bird if fertilized. The yolk contains less water and more protein than the white, some fat, and most of the vitamins and minerals of the egg. These include iron, vitamin A, vitamin D, phosphorus, and calcium, among others. This allows the yolk to be a great source of nutrition for the growing baby bird. Just like the eggshell, the color of the yolk varies depending on the species of bird!

Developing Baby Birds

After an egg is fertilized, the embryo starts developing. On the yolk, there is a very tiny white spot called the embryonic disc.This is what then turns into a baby bird. The amount of time it takes for the bird to hatch depends on the size of the adult bird. For the rest of this blog, we’ll be discussing the timeline of a chicken egg!

In the first few days after an egg is laid, the embryo is microscopic and looks nothing like an adult bird at all. On the fourth day, amniotic fluid will surround the embryo, protecting it and allowing it to move around inside the egg. At this stage, the chick will begin to look less like a blob and more like a bird. Eyes are the first to fully develop. At the end of the first week, the chick’s neck thins out and allows the head to become visibly separate from the rest of its body. The beak also begins to form!

During the chick’s second week of development, its claws and feather follicles form. An important structure begins to grow: the egg-tooth. This sharp little cap on the tip of the beak helps the chick peck its way out of its shell when ready, in a process called pipping. In the last week before hatching, the chick continues to grow until the egg white is completely gone. At this point, the chick will be covered in down, small fluffy feathers that insulate the baby bird as its outer feathers grow.

Pipping

When the chick is in position, with its beak pointing to the air sac, it is ready to hatch. The first thing the chick must do is “pop” the air sac so it has enough oxygen while it works it’s way out of the shell. From there, the chick uses its wing and legs to maneuver itself around in the shell. Using the egg-tooth, the chick will peck at the shell in a circular motion until it reaches a weaker spot.

However, those membranes are very strong, and are hard to break through. But these baby birds are tough! They will continue to peck at and push against the shell until there’s a hole big enough for its head to poke out. In about 12-18 hours, the chick will have pushed its way completely out of the egg and is ready to take on the world! It’s not very cute at this point because it’s still slimy from the fluid inside the egg, but once it dries off the chick will be very fluffy! A few days after hatching, the chick’s egg-tooth will fall off as it is no longer needed.

Build Your Own Birdhouse!

Now that we know all about baby birds, it’s time to make a safe place for the adult birds to build their nests and lay their eggs.

Here’s what you’ll need:

An empty milk jug, one-gallon is the perfect size
Scissors
Popsicle stick or wooden dowel
Decorating supplies! Stickers, paint, etc.

Step 1: A little over halfway down the milk jug, cut a medium-sized circle in the plastic. This will be the opening for the birds to enter and exit their house as they please.

Step 2: Make a tiny puncture about an inch below the holy you just made. Then, carefully slide a popsicle stick or wooden dowel into the opening and secure it with glue, if necessary. This will serve as a branch for the birds to perch on!

Step 3: Decorate! Make this birdhouse your own by adding whatever decorations you want to the outside of the milk jug. You could paint it (with waterproof paint), glue foam shapes to it, add stickers, or just about anything else. Place your finished birdhouse outside and wait to see if any of your neighborhood birds decide to call it home!

References:

http://www.thepoultrysite.com/articles/1459/embryonic-development-day-by-day/

http://www.enchantedlearning.com/subjects/birds/info/chicken/egg.shtml

Image Credits:

Keibel, Franz. “Ten Stages of the Developing Chick”. Released into the public domain. Uploaded on 4/15/17 from wikimedia.org

“Chick and Shell; Black Background”. Released into the public domain. Uploaded on 4/15/17 from publicdomainpictures.net

Egg and birdhouse images property of Discovery Express Kids LLC.

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Sea Monkeys or Aqua Dragons? A Comprehensive Guide to Brine Shrimp

4/10/2017

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When you think of pets, what do you picture? Maybe a dog, or a cat, or perhaps a fish? Have you ever thought about keeping a prehistoric pet, such as brine shrimp? These little crustaceans aren’t anything like you picture when you think of shrimp. While the jumbo shrimp we eat are about 14-21 centimeters in length, brine shrimp can barely reach a maximum size of 1 centimeter! In fact, a typical full grown brine shrimp is about 10 millimeters in length. Their tiny size makes them a perfect food source for other fish - betta fish in particular love brine shrimp as a tasty treat every once in awhile.

So yes, you can raise brine shrimp as food for your fish, or you can keep them as your own prehistoric pets.

The term “brine shrimp” is the common name for a number of organisms in the Artemia genus, and the oldest fossil of these creatures dates back to the Triassic period - over 200 million years ago!

Millions of years ago, these brine shrimp survived by living away from most predators in extremely salty water (up to 25% salinity). In fact, these shrimp are one of the only aquatic species that inhabit the Great Salt Lake in Utah, Nevada. Another survival tactic is their ability to produce dormant eggs, or eggs that don’t hatch until the environment is just right. This way, the baby shrimp can survive through a lack of oxygen, toxic waters, extreme temperatures, and can even be removed from moisture completely.

The dormant eggs are called cysts; the process of encystment is what allowed these shrimp to thrive and remain almost totally biologically unchanged from prehistoric times until now. These cysts are also relatively simple to harvest from the lakes they’re found in, and that makes them excellent candidates for scientific research. For example, when researching the effects of pollution on mammals, brine shrimp have been used extensively as preliminary test subjects due to their great availability.

Scientists have also taken brine shrimp eggs into space to test the impact of radiation on life. In the 1980s on Apollo 16 and 17, eggs were taken on a trip to the moon and back. In 1991, “Forty-four brine shrimp were hatched on the space shuttle Atlantis in April, making them among the first animals ever born in space.” When they returned, only five of them had survived, most likely due to the lack of oxygen and nutrients in their water.

Grow Your Own Shrimp!

Brine shrimp are sold commercially under the brands “Sea Monkeys” and “Aqua Dragons”. These little kits are complete with a tank, eggs, food packets, and instructions - everything you’d need to hatch your own baby brine shrimp. You can even purchase just the eggs and food to save some money and use your own container as a tank.

Once the eggs have hatched (usually within the first 15-24 hours after being placed in the water), it takes approximately 25-30 days for the shrimp to reach their full adult size. During the growing period, they will go through multiple molting stages in which they develop from an embryo to larva to an adult. The males can be clearly recognised by their graspers, which are modified antennae near the head, while females should be starting to show a egg pouch near the tail. They will be an average size of about 8-10 millimeters. If you keep them in water with a lower concentration of salt, the females can produce free-swimming babies instead of dormant eggs!

If kept at optimal conditions, the adult brine shrimp can live up to four months! You can start this process by purchasing one of the many kit options available right now, such as the original Sea Monkeys, or one of the multiple different Aqua Dragons kits. These kits cost anywhere from $10-$30, and are well worth the price for hatching your own low-maintenance pets!

*Discovery Express Kids does not endorse either brand of commercial brine shrimp, nor are the brands sponsored by us. These are simply one of the many options available on the market right now.

References:

"SCIENCE WATCH; Shrimp Hatch in Space." The New York Times, 14 May 1991. Web. 8 Apr. 2017. <http://www.nytimes.com/1991/05/14/science/science-watch-shrimp-hatch-in-space.html>.

http://www.petseahorse.com/everything-you-need-to-know-about-growing-brine-shrimp

https://aquadragons.net/pages/what-are-aqua-dragons

Image Credits:

© Hans Hillewaert. “Brine Shrimp: Laboratory Picture”. Released into the public domain under the Creative Commons Attribution-Share Alike 4.0 International license. Uploaded on 4/6/17 from wikimedia.org

Bassett, Joseph. “Elements of Zoology (1884) - Crabs and Insects”. Released into the public domain. Uploaded on 4/8/17 from flickr.com/internetarchivebookimages

Healy. George. “Cyst Stage of Entamoeba Histolytica”. Released into the public domain. Uploaded on 4/8/17 from wikimedia.org

Manske, Magnus. “Sea Monkeys in Aquarium”. Released into the public domain. Uploaded on 4/8/17 from wikimedia.org

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Flight and Paper Airplanes

4/3/2017

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If you’ve ever folded a piece of paper, chances are you were making a paper airplane. It’s possible to make paper planes look similar to their giant counterparts, but most of the time we just like to make simple ones that we can construct quickly and toss into the air! Have you ever noticed that some designs fly faster or farther than others? Well, there’s a few scientific explanations for this that we’ll discuss in today’s blog.

Number One: Newton’s Law of Motion

The first theory we’ll look at is this: airplanes can fly because their wings make the air deflect downward, which lifts the plane as it is forced upward. Sir Isaac Newton (1643-1727) is well known for his discovery of the law of gravity, but he also discovered the Laws of Motion, one of which states that for every action, there is an equal and opposite reaction. As this law suggests, the wings of an airplane must do something to the air to make it react and push the plane up - we call this lift.

We can see another good example of this law in kites, where the forces acting on them include their own weight, the lift and drag (a force that works opposite of a moving object’s lift), and the tension in the line connecting the kite to you. When all of these forces balance out, the kite flies at a stable altitude, or height in the air. If the wind outside picks up, the kite’s altitude will increase (if you let out a bit more of its controlling line), causing the lift and drag forces to increase as well. When this happens, the forces are no longer balanced and there is a net - or total - vertical force applied on the kite, and in return, it moves vertically instead of staying in one place. If we take out the tension force of the line, we can apply this concept to an airplane!

Number Two: Bernoulli’s Principle

Another theory of interest involves motion in a fluid. David Bernoulli (1700-1782) discovered that as the velocity in a fluid increases, its pressure decreases in return. His principle applies to any fluid, and since air is a fluid, this applies to air as well. This means that airplanes can fly because the pressure above its wing is less than the pressure below its wing.

Let’s take a look at this principle in a different setting. Imagine a room full of people running around in different directions. With so many people going different ways, they’re bound to collide with each other - and the walls - multiple times. Now if we have the same amount of people running in one direction down a hall, there will be fewer and less intense collisions. When we apply concepts from physics to these groups of people, we can see that in the closed room, the overall (net) speed was zero, and the pressure (shown by the rate of collisions) was quite high. In the hallway, the net speed of the group was greater than zero and the pressure was much lower than in the room.

In that example, we see that there are two types of pressure: static pressure and total (or ram) pressure. When applied to a flying airplane, the static pressure would be what we’d have when the plane is flying with the wind, instead of against it. Air presses against the plane equally in all directions, with this pressure decreasing as the plane’s speed increases - which is defined as the Bernoulli principle!

Number Three: The Coanda Effect

You might also notice that some airplanes have curved wings. A common question regarding the Bernoulli principle is this: why are curved wings important? Well, according to Henri Coanda (1886-1972). “a fluid stream which comes in contact with a gently curved solid surface will tend to follow that surface.” By curving the top of an airplane's wing, air above it has to travel farther (as the distance is greater) than the air below, forcing the air to move faster. The result is lower pressure on top and more pressure on the bottom. This effect amplifies the Bernoulli principle, but as most paper airplanes (and birds!) have “flat” wings so it’s not as important as the other two laws of flight.

Try it Out!

To demonstrate the Bernoulli principle, this simple experiment requires only two pieces of paper! Hold one piece of paper horizontally in each hand, close to your face. Now blow between them and you’ll see that the pieces of paper will get closer to each other, instead of farther away.

Make your own paper airplane! In the file attached to this post, we’ve created a document to help you fold your paper plane. Print it out and follow the instructions in the video to create your own paper airplane. The first step is to fold the paper in half, lengthwise along dotted line number 1. Then fold the edges of the paper down to where it’s folded in half, starting with dotted line number two, on both sides. Do the same for line number 3 and number 4. Keep the flaps on the outside so that the paper can catch some air!

paper_airplane_template.pdf
File Size:	88 kb
File Type:	pdf

Download File

References:

https://www.grc.nasa.gov/www/k-12/airplane/newton1k.html

http://www.aviation-for-kids.com/experiments.html

http://www.thermofluids.co.uk/effect.php

Image Credits:

“Paper Plane Vector Illustration”. Released into the public domain. Uploaded on 4/1/2017 from publicdomainvectors.org.

Kratochvil, Petr. “Flying Plane”. Released into the public domain. Uploaded on 4/2/2017 from publicdomainpictures.net

Siedlecki, Piotr. “Razorback Plane”. Released into the public domain. Uploaded on 4/1/2017 from publicdomainpictures.net

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Spherification and Edible Water Spheres

Baby Birds and How They Hatch

Sea Monkeys or Aqua Dragons? A Comprehensive Guide to Brine Shrimp

Flight and Paper Airplanes

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