In the not-so-distant future, surfing the web at 35,000 feet will be just as reliable as going online at your favorite coffee shop. Who do we thank for this aeronautical innovation? Teams of engineers have been leading the charge to bring us quality in-flight internet, but there’s another WiFi hero you probably didn’t expect… potatoes!
Providing strong and consistent WiFi throughout a crowded airplane cabin presents an interesting challenge. Because the human body can interfere with WiFi signals, a cabin full of passengers can wreak havoc on an otherwise stable internet connection. But running rigorous WiFi tests on a full, airborne flight is impractical. And holding passengers hostage for days in a grounded airplane cabin is just unthinkable.
Enter the potato. Potatoes and humans have comparable dielectric properties, meaning that they similarly interact (and interfere) with WiFi signals. Engineers at Boeing used this to their advantage, creating a new way to test the quality of airline WiFi sans humans. The aptly named “project SPUDS” (Synthetic Personnel Using Dielectric Substitution) used 20,000 pounds of potatoes to quickly optimize the effectiveness and safety of WiFi signals aboard decommissioned airplanes.
When this breakthrough hit newsstands back in 2012, Boeing made it clear that potatoes weren’t in their original plan. In reality, SPUDS serendipitously took off when the research team stumbled across a paper from the Journal of Food Science describing the dielectric properties of 15 fruits and vegetables.
It turns out that food scientists have been studying the dielectric properties of fruits and vegetables for quite some time, as these properties determine how foods behave in a microwave oven. Dielectric properties describe how materials interact with electromagnetic waves, including those emitted by microwave ovens. In particular, dielectric properties determine how much energy a food can absorb in a microwave oven and how far into the food the microwaves will penetrate. Such information is especially useful to industrial food processors who often use microwaves to cook, pasteurize, dry, or preserve various food products.
WiFi signals are typically transmitted at a frequency (2.40 GHz) that is remarkably close to the frequency produced by microwave ovens (2.45 GHz). Thanks to the work of food science researchers, Boeing engineers could confidently choose the potato as their ideal human stand-in.
Thinking about this story, it’s hard not to marvel at the interconnectedness of science. Those food scientists probably never imagined that their work would eventually help improve internet access. And those Boeing engineers must have been pretty surprised to find themselves perusing the latest in food science research. It can be difficult to predict where our ongoing pursuit of knowledge will lead us, but one thing is clear—when it comes to expanding our view of science and making new connections, the sky’s the limit.
“There’s so much great food yet to discover that we can grow, so I just love discovering new varieties, crops, things that our customers and myself have never tried before.”
– Alex Weiser, 2013 Science & Food course Read more
Tomorrow is Pi Day, so here are a few fun videos to help you celebrate the most mathematically mouthwatering day of the year. Happy Pi(e) Day! Read more
The 2014 UCLA Science & Food public lecture series is here!
General admission tickets are available for $25 from the UCLA Central Ticket Office (CTO) . Tickets can be purchased from the UCLA CTO over the phone or in person and will not include additional fees or surcharges. The UCLA CTO is located on-campus and is open Monday–Friday, 10am –4pm. A UCLA CTO representative can be reached during these hours at 310-825-2101. Tickets can also be purchased online from Ticketmaster for $25 plus additional fees. A limited number of $5 student tickets are available to current UCLA students. These must be purchased in person at the UCLA CTO with a valid Bruin Card.
The Science of Sushi
Dr. Ole Mouritsen & Chef Morihiro Onodera
Wednesday April 23, 2014 at 7:00pm
Schoenberg Hall, UCLA
In this lecture, Dr. Ole Mouritsen will illuminate the science underlying sashimi, nori, sushi rice, umami, and more. He will be joined by Chef Morihiro Onodera who will share his approach to sushi as well as an inside look into his partnership with a rice farm in Uruguay.
How We Taste
Dr. Dana Small, Chef Wylie Dufresne, & Peter Meehan
Wednesday May 14, 2014 at 7:00pm
Schoenberg Hall, UCLA
In this lecture, we will explore how we taste from the perspectives of a scientist, a chef, and a food writer. Dr. Dana Small will describe how our brains respond to flavors, and shed light on the link to obesity. She will be joined by Chef Wylie Dufresne who will present his creative approach to generating surprising food flavors and textures. Peter Meehan will share his experiences with food and taste and how they have shaped his writing, both as a cookbook author and former writer for The New York Times.
Harnessing Creativity (and the Science of Pie)
Dave Arnold & Chef Lena Kwak
Sunday June 1, 2014 at 2:30pm
Ackerman Grand Ballroom, UCLA
At this event, Dave Arnold will discuss his latest culinary innovations and the role of creativity in food. He will be joined by Chef Lena Kwak who will share her process of invention, research, and discovery in the kitchen. Also at this event, students of the Science & Food course will present the results of their apple pie projects, including their freshly baked pies in a large-scale pie tasting. The event will close with an Iron-Chef style discussion of the winning pies featuring the keynote speakers and renowned judges from the Los Angeles community.
Chocolate-covered strawberries have an innate beauty in their simplicity, making this snack both sweet and decadent. But this gourmet treat does not have to be expensive nor only savored at special events. Although it’s not quite as simple as dipping strawberries into soupy chocolate sauce, you can easily make chocolate-covered strawberries in your very own kitchen with a basket of strawberries, a bag of chocolate, and a little patience.
To perfect the crafting of chocolate-covered strawberries, it helps to first consider the composition of chocolate. Chocolate contains only a few ingredients: fat, sugars, proteins, and soy lecithin as emulsifier that holds everything together [1,2]. Cocoa butter, a fat that is derived from cocoa beans, makes up the majority of chocolate. Like many vegetable fats, cocoa butter is a mixture of fatty molecules called triacylglycerols. Different types of triacylglycerols—saturated, monounsaturated, polyunsaturated—have their own thermal and structural properties. Roughly 80% of cocoa butter are monounsaturated triacylglycerols . The secret to chocolate perfection lies in the microscopic arrangement of these molecules. The texture (smooth vs. lumpy), appearance (glossy vs. dull), and melting temperature of chocolate (in your mouth at 98°F vs. in your hand at 82°F) all depend on how triacylglycerols pack together in the finished chocolate product.
Triacylglycerols are elongated, spindly molecules that can be packed together in different ways, sort of like long, skinny Legos. The three main ways that triacylglycerols can pack together are named α, β’, and β . A pure mixture of triacylglycerols will form the most stable structure, β , and quality chocolate that is hard, smooth, and shiny will predominantly contain this β structure. Unfortunately, cocoa butter isn’t purely one type of triacylglycerol: while the 80% monounsaturated triacylglycerols will tend to pack together nicely into perfect β structures, the other 20% of cocoa butter fat molecules can interfere and lead to less stable α or β′ structures. As shown in Table 1, chocolate can take on different combinations of α, β′, and β structures, categorized in order of increasing stability as crystals I-VI [2,3]. Crystal V possesses only the β structure, and so it boasts the most desirable chocolate characteristics, such as good sheen, satisfying snap, and melt-in-your-mouth smoothness.
Table 1. Properties of chocolate crystals (adapted from ).
|Crystal||Structure||Melting Temp (°F)||Chocolate Characteristics|
|I||β′sub(α)||63||Dull, soft, crumbly, melts too easily|
|II||α||70||Dull, soft, crumbly, melts too easily|
|III||β′2||79||Dull, firm, poor snap, melts too easily|
|IV||β′1||82||Dull, firm, poor snap, melts too easily|
|V||β2||93||Glossy, firm, best snap, melts near body temp|
|VI||β1||97||Hard, takes weeks to form|
Unfortunately, getting chocolate to form the desired crystal type is easier said than done. When chocolate is melted and then left alone to re-harden on its own terms, uncontrolled crystallization occurs: any and all of the six crystal types will form at random. Chocolate that has been allowed to set this way ends up clumpy and chalky. To control crystallization and select for crystal V, the chocolate must be tempered. Through the tempering process, chocolate is first heated to 110-130°F to melt all the different crystal types. Most importantly, the temperature has to be higher than 82°F to melt the inferior crystals I-IV. Melted chocolate is then cooled down by adding “seeds” of chocolate that already contain only crystal V. These seeds are usually just pieces of chocolate that has already been tempered. Any piece of chocolate—chips, buttons, or chopped— can be used, as the majority of chocolate on the market has already been tempered. These seeds slowly cool the melted chocolate and act as a molecular template from which additional crystal V structures can grow . As the chocolate cools, the stable crystal V will come together into a dense, even network, creating that lustrous, firm chocolate coating.
But beware: a drop of water can ruin all that hard work and perfectly tempered chocolate by causing it to seize. During the manufacturing process, water is removed from the chocolate, leaving behind a blend of fats and sugars. Introducing water to melted chocolate causes the sugar molecules to clump together in a process known as seizing . These wet, sticky sugar clusters result in a grainy, thick batch of chocolate.
Seizing can happen when chocolate is melted in a double boiler, as water from the steam can get into the chocolate. It can also happen when pockets of chocolate are accidentally burnt. Burning is a chemical reaction that oxidizes the fats and sugars to produce carbon dioxide and water. Water that forms in the burnt pockets of chocolate will cause the rest of the batch to seize. But have no fear! Seized chocolate is not completely ruined: it can be saved by adding even more water or other liquids such as cream. Though it may seem counterintuitive, adding more water actually dissolves the sugar clumps, breaking them apart so that the chocolate can become smooth and creamy again . Unfortunately, because there is now moisture in the chocolate, it will not dry and harden into a chocolate shell anymore. Chocolate rescued in this way can be used for hot chocolate, icings, fillings, or ganaches, which means you can still make an impressive chocolate treat even if the chocolate-covered strawberries don’t work out.
1 lb. strawberries
16oz milk chocolate chips
Thermometer (optional, but would be helpful)
1. Melt half to two-thirds of the chocolate chips…
…In a double boiler: Stir constantly. Be sure steam doesn’t escape and sink into the chocolate. Do not cover.
…In the microwave: Heat on high 1 minute. Do not cover. Remove from the microwave and stir. If all the chocolate has not melted, heat again for 5-10 seconds. Repeat until completely melted
Note: If possible, avoid using a heat-retaining container like glass, which may burn the chocolate. Plastic is preferred.
2. Once completely melted, carefully continue heating until the temperature is 90-95°F.
3. Remove from heat, then add chocolate chips. Stir until the chips have melted and the chocolate is 82-88°F.
4. To test if the chocolate is ready, spread a thin layer on the back of a spoon or a piece of paper. It should harden in less than 3 minutes. If it doesn’t, stir in more chocolate chips.
5. When the chocolate is ready, carefully dip in strawberries. Make sure the strawberries are dry, before dipping. Allow dipped strawberries to dry on a sheet of parchment paper.
- Corriher, S. Chocolate, Chocolate, Chocolate. American Chemical Society: The Elements of Chocolate. October 2007; <http://acselementsofchocolate.typepad.com/elements_of_chocolate/Chocolate.html>
- Loisel C, Keller G, Lecq G, Bourgaux C, Ollivon M. Phase Transitions and Polymorphism of Cocoa Butter. Journal of the American Oil Chemists’ Society. 1998; 75(4): 425-439.
- Rowat A, Hollar K, Stone H, Rosenberg D. The Science of Chocolate: Interactive Activities on Phase Transitions, Emulsification, and Nucleation. Journal of Chemical Education. January 2011; 88(1): 29-33.
- Weiss J, Decker E, McClements J, Kristbergsson K, Helgason T, Awad T. Solid Lipid Nanoparticles as Delivery Systems for Bioactive Food Components. Food Biophysics. June 2008; 3(2): 146-154