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Soda Consumption & Fat Perception

ice_cream_kids

Researchers at University of Alaska analyze carbon isotopes to measure soda consumption, while German scientists study how our psychological state affects how we taste and perceive fat.

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Fish Bladder Beer & Laboratory Meat

Guinness_da_Bar

In his lecture Primitive X Modern, Chef Alex Atala questioned our cultural interpretations of what is “edible” or “delicious” by feeding us Amazonian ants. It turns out that insects aren’t the only controversial “food” in the culinary world—Smithsonian Magazine uncovers an unexpected ingredient in beer, while NPR explores the world of in vitro (i.e. test tube) meat. Read more

Stressed Carrots & A Tastier Tomato

StressedCarrots

It turns out that giving fruits and veggies a good night’s sleep isn’t the only way to make them better to eat. Researchers at Texas A&M have shown that carrots produce more antioxidants in response to the “stress” of being chopped or shredded, while scientists at the University of Florida are working hard to make a tastier and more nutritious tomato. Read more

The Benefits of Well-Rested Produce

Cabbage - credit postbear

Beauty rest isn’t just for people—cabbages also benefit from a good night’s sleep. (photobear/Flickr)

In 400 BCE, the Greek admiral Androsthenes wrote* of a tree that

“opens together with the rising sun . . . and closes for the night. And the country-dwellers say that it goes to sleep.”

Over the next 2000 years, researchers discovered that the daily cycles first observed by Androsthenes fall into 24-hour periods similar to our own cycles of waking and sleeping [1]. In plants, these circadian rhythms help control everything from the time a plant flowers to its ability to adapt to cold weather [2]. Plants can even use their internal clocks to do arithmetic calculations to budget their energy supplies through the night [3].

But what happens when part of a plant is harvested for food? In a recent study, researchers at Rice University and UC Davis showed that cabbages can exhibit circadian rhythms as long as a week after harvest.

As with any plant, cabbages experience circadian rhythms while growing out in the field; however, cabbages stuck in the constant dark of a delivery truck or light of a 24-hour grocery store will inevitably lose their sense of time. Like travelers adjusting to a new time zone, cabbages deprived of cyclic light conditions suffer a severe bout of veggie jet lag. And just as travelers overcome jet lag by readjusting their sleep cycles, cabbages can “re-entrain” their circadian rhythms by being exposed to cyclic light conditions. This also works with spinach, zucchini, sweet potato, carrots, and blueberries, suggesting that post-harvest circadian rhythms are a general characteristic of many, if not all, fruits and vegetables.

The ability to re-entrain circadian rhythms in produce presents an intriguing new way to improve the palatability and even nutrition of our fruits and vegetables. In the wild, circadian rhythms can help plants defend themselves against hungry herbivores. The researchers showed that cabbages with re-entrained circadian rhythms use a similar mechanism to avoid becoming an afternoon snack for plant-eating larvae—with less damage from hungry larvae, re-entrained cabbages appear fresher and tastier than cabbages kept under constant light or dark conditions.

Circadian rhythms help protect produce from herbivores. Samples from cabbages kept in (A) cyclic “in phase” light, (B) constant light, or (C) constant dark conditions were fed to larvae. Cabbages kept in constant light or constant dark sustained the most damage.

Cabbages fight off larvae and other pests thanks to molecules called glucosinolates. Any cabbage can produce these molecules, but re-entrained cabbages produce glucosinolates in sync with their circadian rhythms. Because larvae also experience circadian rhythms, re-entrained cabbages get an extra boost of molecular larvae-fighting power just when they need it the most.

While glucosinolates are bad news for larvae, they have valuable anti-cancer properties when consumed by humans. In fact, the very molecules that plants create to defend themselves against their environment are often beneficial for our own health. Future research will show whether such phytonutrients in other types of produce can also be reconditioned to accumulate in predictable 24-hour cycles. Taking advantage of circadian rhythms in fresh produce could then give us more control over the way phytonutrients accumulate over time, helping us maximize the nutritional benefits of our fruits and vegetables. Improving the nutrition of our food could be as simple as giving our produce a good night’s sleep.

 

*The original Greek passage comes from Botanische forschungen des Alexanderzuges [4] with a very special thank you to Tovah Keynton for the English translation. The drawings (also from Botanische) depict the tree leaves transitioning into and then assuming their “sleeping position.”
TamarindTreeRhythms

References Cited

  1. McClung CR (2006) Plant Circadian Rhythms. PLANT CELL ONLINE 18: 792–803. doi:10.1105/tpc.106.040980.
  2. Kinmonth-Schultz HA, Golembeski GS, Imaizumi T (2013) Circadian clock-regulated physiological outputs: Dynamic responses in nature. Semin Cell Dev Biol 24: 407–413. doi:10.1016/j.semcdb.2013.02.006.
  3. Scialdone A, Mugford ST, Feike D, Skeffington A, Borrill P, et al. (2013) Arabidopsis plants perform arithmetic division to prevent starvation at night. eLife 2: e00669–e00669. doi:10.7554/eLife.00669.
  4. Bretzl H (1903) Botanische forschungen des Alexanderzuges. B. G. Teubner.

Liz Roth-JohnsonAbout the author: Liz Roth-Johnson is a Ph.D. candidate in Molecular Biology at UCLA. If she’s not in the lab, you can usually find her experimenting in the kitchen.

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Wild Phytonutrients & Resveratrol Research

DomesticatedvsWildCorn

Author Jo Robinson explores the agricultural history of phytonutrients, while Harvard researchers move us a step closer toward understanding how the resveratrol in red wine and chocolate could be hindering the aging process. Read more

Rachel Dutton

Rachel Dutton is a Bauer fellow at Harvard University where she uses cheese to study microbial ecosystems. She has collaborated with chefs David Chang and Dan Felder of Momofuku, and her research has been featured in Lucky Peach Magazine, The Boston Globe, NPR, The New York Times, and on the PBS TV series Mind of a Chef.

Rachel Dutton photo 2013Dutton Lab at JHF

What hooked you on science?
I blame microbes for hooking me on science. I am just completely amazed at how versatile and powerful they are—and we can’t even see them!
The coolest example of science in your food?
My lab studies how microbes form communities in cheese. I think the coolest thing is that these microbes are doing everything from fighting to sending out chemical messages, and all this is happening as we eat a piece of cheese.
The food you find most fascinating?
I guess I am biased, but I think cheese is absolutely fascinating. I started out thinking that cheese was this relatively simple thing, but the more I work with it the more respect and awe I have of how complex and nuanced it can be. Both in terms of the flavor and the science. It is also incredibly interesting from the perspective of its history and cultural significance, and there are so many passionate people working with cheese.
What scientific concept–food related or otherwise–do you find most fascinating?
I think the most fascinating food related concept right now is that microbes could be used as new sources of flavor in foods. Much of the flavor we currently have in fermented foods comes from the microbes themselves. And we know that microbes have an incredible diversity of metabolic pathways, so what if we found microbes that could ferment foods to give it totally new properties?
Your best example of a food that is better because of science?
Chocolate.
Are there any analogies you like to use to explain difficult or counter-intuitive food science concepts?
The way that we identify species of microbes by sequencing their DNA can be a tricky concept. I like to compare it to matching fingerprints in a database, like in CSI, except that the fingerprints microbes have are unique sequences in their DNA.
How does your scientific knowledge or training impact the way you cook? Do you conduct science experiments in the kitchen?
I think I use both cooking and science to explore and learn. In the lab, I use science as a way to learn more about the way microbes behave. In the kitchen, I like to cook things that allow me to explore new cultures or ingredients.
One kitchen tool you could not live without?
I use a scale a lot. Even when I don’t need to, sometimes I’m just curious how much something weighs.
Five things most likely to be found in your fridge?
Whole milk yogurt, lemons or limes, maple syrup, mayonnaise, and ginger.
Your all-time favorite ingredient?
I think steamed clams are my favorite food, and fermented black soybeans are a favorite ingredient. I’m also a sucker for anything with cardamom in it.
Favorite cookbook?
When I have time on the weekends, sometimes I’ll cook from Rick Bayless’ Mexican Kitchen. I grew up in California and studied for a while in Mexico, and I love Mexican food and culture, especially from central and southern Mexico. The other cookbook I’m really enjoying right now is Yotam Ottolenghi’s Plenty.
Your standard breakfast?
I usually rotate between yogurt with honey and granola, oatmeal with maple syrup and walnuts, and eggs on toast.

Human Cheese

Cheese1

Have you ever been offered a fancy cheese that smelled more like a used gym sock than something edible? Odor artist Sissel Tolaas and researcher Christina Agapakis took this idea and ran with it, with their project Synthetic Aesthetics. The duo used bacteria isolated from human hands, feet, noses, and armpits to generate cheese!

Many cheeses, like beer, wine, and yogurt, are the product of fermentation. Fermentation occurs when microorganisms such as yeast and bacteria convert carbohydrates such as sugar into alcohols, gasses, and acids to generate energy in the absence of oxygen. One common cheese-making type of bacterium, Lactobacillus, breaks down lactose, the primary milk sugar, to lactic acid. This results in lowering the pH of the milk, which as pointed out in a previous post, causes coagulation and solidification into cheese. The work of microorganisms in cheese also results in the creation of many other byproducts that give cheeses their unique smell, texture, and flavor profiles. For example, the bacterium, Propionibacterium freudenreichii, generates carbon dioxide gas in the process of making swiss cheese and causes its characteristic holes [1]. Penicillium roqueforti, which is related to the fungus that helps produce the antibiotic, penicillin, gives blue cheese it’s distinct aroma and look [1].

Microorganisms that use fermentation are found everywhere. Tolaas and Agapakis realized that the human body shared many characteristics with the environments for creating cheese. On a hot day or before a hot date, your armpits may be just as warm and moist as an industrial cheese incubator. Furthermore, cheese-making bacteria like Lactobacillus are common inhabitants in the mammalian gut [1]. With this information, they isolated bacteria from hands, feet, noses, and armpits and added them to whole milk to serve as starter cultures.

Figure 1. (A) Swabs from various human body parts incubating in raw milk. (B) Cheeses after solidifying. While no cheeses were consumed, they were evaluated with an odor survey and by DNA sequencing to identify the bacteria cultures present in each cheese.
Figure 2. Samples prepped for the smell survey. Participants of the survey were asked to smell the samples and provide a description of the odors they detected.

Here are the results:

Source Bacteria Isolated Odors
Hand-1 Providencia vermicola
Morganella morganii
Proteus mirabilis
yeast, ocean salt, sour old cheese, feet
Foot-1 Providencia vermicola
Morganella morganii
Proteus mirabilis
sweat, big toe nail, cat feet, sweet, milky, orange juice in the fridge too long, fungus, buttery cheese, soapy, light perfume
Armpit-1 Providencia vermicola
Morganella morganii
Proteus mirabilis
Feta cheese, Turkish shop, nutty, fruity, fishy
Nose-2 Providencia vermicola
Morganella morganii
Proteus mirabilis
cheesy feet, cow, cheese factory, old subway station, toilet cleaner
Armpit-2 Enterococcus faecalis
Hafnia alvei
neutral, perfumed, industrial, synthetic, fermentation, car pollution, burning, sharp, chemical
Armpit-3 Micobacterium lactium
Enterococcus faecalis
Bacillus pumilus
Bacillus clausii
neutral, sour, floral, smooth, yogurt
Foot-5 Providencia vermicola
Proteus mirabilis
yeast, jam, feet, putrid, sour, rotten
Armpit-4 Enterococcus faecalis yogurt, sour, fresh cream, butter, whey

The cheeses displayed a diverse range of bacterial species and odors. Interestingly while some cheeses smelled like “old subway station” or “cat feet,” others exuded the familiar & appetizing flavors of “yogurt,” “feta cheese,” and “light perfume.” Furthermore, some of the bacteria isolated were common to various cheeses. For example, Enterococcus faecalis is a lactic acid bacterium found in raw milk and cheeses, like farmhouse cheddar varieties [2]. Proteus mirabilis is related to Proteus vulgaris, which is responsible for giving surface-ripened cheeses like Limburger and Munster a strong aroma [3].

While these bacterial cultures may not serve as the basis of a new type of artisan cheese, Agapakis notes:

“These cheeses are scientific as well as artistic objects, challenging us to rethink our relationship with our bacteria and with our biotechnology. . . . The cross-over between bacteria found on cheese and on human skin offers a tantalizing hint at how our bacterial symbiotes have come to be part of our culinary cultures.”

In the face of diminishing resources, we are reminded that untapped reservoirs, which may be literally under our noses, might contain hidden treasures that could change the way we generate and produce food.


Online Resources

  1. More about this project
  2. More about Christina Agapakis
  3. More about Sissel Tolaas
  4. More about bacteria found on the human body
  5. More about the basics of cheese making


References cited

  1. Agapakis, C. 2011. Human Cultures and Microbial Ecosystems. http://agapakis.com/cheese.pdf
  2. Gelsomino. R. et al. 2002. Sources of Enterococci in Farmhouse Raw-Milk Cheese. Applied and Environmental Microbiology 68(7): 3560-3565.
  3. Deetae. P. et al. 2009. Effects of Proteus vulgaris growth on the establishment of a cheese microbial community and on the production of volatile aroma compounds in a model cheese. Journal of Applied Microbiology 107(4):1404-1413.

Vince ReyesAbout the author: Vince C Reyes earned his Ph.D. in Civil Engineering at UCLA. Vince loves to explore the deliciousness of all things edible.

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Understanding Umami

Imagine taking a bite of your favorite food. Is it sweet? Salty? Does it have a sour bite or a hint of bitterness? Maybe even a touch of savory umami?

Every time we eat, our taste buds sample these five basic taste qualities. Taste receptors decorating the surface of each taste bud interact with specific molecules; the corresponding flavor sensation then gets sent to your brain. Umami receptors, for example, sense the molecule glutamate. When free glutamate in our food—either naturally occurring or from added MSG—interacts with an umami receptor, we taste a delicious savory flavor.

Although glutamate is the primary source of umami flavor, certain molecules called nucleotides can enhance the umami sensation. Because nucleotides make up the genetic material (DNA and RNA) of all living things, nucleotides are ubiquitous in many of the foods we eat. Nucleotides themselves cannot activate umami taste receptors, but they can intensify the umami sensation caused by glutamate. Intrigued by this phenomenon, scientists Ole Mouritsen and Himanshu Khandelia recently published a paper exploring how one nucleotide, guanosine-5ʹ-monophosphate (GMP), might work together with glutamate to activate umami taste receptors.

Only one of the three known umami taste receptors can interact with both glutamate and GMP. This so-called “T1R1/T1R3” receptor switches between two states: an “off” state when no glutamate is present and an “on” state when glutamate is attached to the receptor. To understand how GMP might affect these two states, Mouritsen and Khandelia ran a series of computer simulations testing the receptor’s behavior in the presence or absence of GMP. As expected, glutamate caused the receptor to exist in the “on” state more than the “off” state. When GMP was added to the simulation, both GMP and glutamate interacted with the receptor to further stabilize the “on” state.

Model of the T1R1/T1R3 umami taste receptor. The taste receptor (in blue) is “off” when no glutamate is present. Glutamate interacts with the receptor, stabilizing the “on” state and signaling an umami taste sensation. Glutamate and GMP together bind the receptor and further stabilize the “on” state, presumably leading to a longer, more intense umami sensation.

Besides providing a compelling molecular model for umami taste sensation, this and future work on taste receptors may help us become more savvy seasoners in the kitchen. Because umami taste receptors are similar to the taste receptors for sweet and bitter, understanding how molecules like GMP enhance umami sensations can help us develop enhancers for other taste sensations. Just as GMP makes glutamate taste more intensely umami, a sweet enhancer could make sugar taste sweeter with no added calories. Identifying more taste enhancing molecules like GMP could bring a whole new dimension to the way we cook in the future. Forget about salt and pepper—the flavor enhancers are coming.


ProfileImageSmallAbout the author: Liz Roth-Johnson is a Ph.D. candidate in Molecular Biology at UCLA. If she’s not in the lab, you can usually find her experimenting in the kitchen.

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Veronica Trevizo

Veronica Trevizo is the Development Chef at Momofuku Culinary Lab. Veronica hails from California, where she was born in San Diego, attended the California Culinary Academy, and worked at such venues as the Four Seasons in San Diego and the San Francisco establishments Jardinière and Michael Minas. She also spent time working at Spagos in Maui and has worked all over Europe, completing stages in Spain and at Noma in Copenhagen, before relocating to New York to work in the Momofuku Culinary Lab.

Veronica Trevizo courtesy of Port Magazine

Photo courtesy of Port Magazine

What hooked you on cooking?
I grew up in a traditional Hispanic family in which every month there was some sort of barbecue or grand family dinner. My fondest memories of my childhood revolve around those special occasions. I always found myself in the kitchen with my mother and Tias preparing the meals, feeling excited as I watched them cook and sneaking bits of food and knowledge. When they tried to shoo me from the kitchen, I stayed, and to this day I don’t want to be anywhere else.
The coolest example of science in your food?
I would have to agree with Dan and select our ongoing projects based around microbes and fermentation. At the Momofuku Culinary Lab we have been quite successful with our projects involving miso and other traditional fermentative products. These projects generated relationships and connections with experts in the scientific field, furthering our understanding and abilities to explore just how far we can evolve food sciences. It is my personal goal to continue to progress the collaboration between food and academia.
The food you find most fascinating?
Processed food. I find it fascinating that so much work and money is used to produce foods that are unhealthy, poor tasting, and downright bad for people.
What scientific concept–food related or otherwise–do you find most fascinating?
• Maillard reaction: when compounds form together, creating new compounds that make a very distinctive flavor. For example, crust on bread and sugar to make caramels.
• MSG: there are so many ideas out there but none that are really true. This subject always seems to start a conversation.
• Neurogastronomy: an understanding of why we perceive something as delicious or disgusting fascinates me. The age old fight: “my mother’s food is better than yours!” There is so much going on that we just don’t fully understand yet.
Your best example of a food that is better because of science?
Milk. Pasteurization is a science win that absolutely highlights the importance of science in food.
How do you think science will impact your world of food in the next 5 years?
In the past years, we’ve seen the huge impact that science has had in our kitchens. A great example is the science-imagined and science-enabled equipment like centrifuges, cryovacs, and sous vide machines. Using equipment that is seen in laboratories now in almost every kitchen makes both fields more robust and makes our work even more informative for the public. As a cook, it has also helped me understand that scientists and chefs are not so different. I would say the impact is already here in the culinary world but I definitely see much more collaboration in the future. It starts with equipment and continues with the sharing of knowledge.
One kitchen tool you could not live without?
A knife.
Five things most likely to be found in your fridge?
• Butter
• Valentina hot sauce
• Leftover takeout
• Homemade penicillin projects (aka some old bread…)
• Honestly, not that much! The fridge I’m thinking about is always the one at the lab.
Your all-time favorite ingredient?
I can’t live without salt!
Favorite cookbook?
My favorite cookbook… there are so many. I do love Julia Child and remember reading Mastering the Art of French Cooking religiously as a child.
Your standard breakfast?
I usually just have black coffee. But I do love chilaquiles!

Daniel Felder

Daniel Felder is the Head of Research and Development at the Momofuku Culinary Lab. Dan is originally from Roxbury, Connecticut, and began working in restaurants at the age of eighteen while he was studying at Union College in Saratoga Springs, New York. He moved to New York City and joined the Momofuku team in 2008 at Noodle Bar and Ko, and now at the Momofuku Culinary Lab.

Dan Felder credit Gabriele Stabile

Photo courtesy of Gabriele Stabile

What hooked you on cooking?
Both my parents are quite good home cooks, and let me cook with them from a really early age, sitting at the counter watching and then helping as I got older. My great-aunt is an amazing home cook, and still lives in Rome. She had an impact on me and my cousins, as four of us now work in the food industry. Learning from her was a challenge; she wouldn’t give up her secrets unless you earned them, usually by doing some unrelated task for an extended period of time. Once I got my food in the door of professional kitchens, it was a similar scenario. You have to earn knowledge. That’s the slippery slope for me; learning something new in the kitchen repeatedly opens my eyes to how much more there is to learn.
The coolest example of science in your food?
One of the coolest examples is probably the ongoing projects at the Culinary Lab based around microbes and fermentation. The heart of this process for us was really the application of scientific methodology. Applying scientific structure and procedures to how we pursue a question has actually given us a lot of freedom in how we experiment. By breaking down and understanding the mechanics of a process we can’t see with the naked eye, we can start with a grounded hypothesis and begin manipulating variables until we get to where we want to be. Our miso is a good example of this process.
The food you find most fascinating?
I am really fascinated by starches, grains, root vegetables, etc. I realize it is pretty familiar and basic territory, but I think the bio-technological capacity of rice and grains, for example, is really incredible. We have only scratched the surface of what we can do with it. There has been a lot of research with corn and different starches for industrial purposes and alcohol, but as cooks, I think we have so much more to discover.
What scientific concept–food related or otherwise–do you find most fascinating?
• Why starburst candies cause extreme salivation.
(More of a question than a concept—potential student project?)
• Enzymes.
• Metabolic pathways. Specifically, how the body metabolizes sugars and amino acids.
• Hydrolysis of protein.
• Correlation of fermentation to larger biological processes.
Your best example of a food that is better because of science?
Italian salad dressing.
How do you think science will impact your world of food in the next 5 years?
Not to be gross, but the idea of “out of body digestion” is really interesting to me. Can we extrapolate and apply the mechanism of digestive processes in the natural world as catalysts in the kitchen? Fermentation is a familiar example of this idea, but I believe we can take it a bit further by looking at more diverse biological processes, and hopefully reveal new nutritive resources (hopefully delicious ones) as a result.
As a corollary, the things Alex Atala, Noma, and the Nordic Food Lab have found by exploring potential food sources in their respective environments is both very interesting and indicative of what is in the immediate future for science and food. In our lab, we are looking at how we can extend this idea to process as well. ow can we disinter biological processes from the natural world and bring them into the kitchen?
One kitchen tool you could not live without?
Rene and Lars gave the perfect answer: spoon. I can’t compete with that. If I had to pick one for the Momofuku Culinary Lab, I would go with a Dremel.
Five things most likely to be found in your fridge?
• Fruit and veggies
• Good Seasonings Italian salad dressing
(the one in the packets that comes with the cruet)
• An excess of condiments
• Olives and pickles
• Budweiser
Your all-time favorite ingredient?
That’s hard to say. Butter, maybe? Bread?
Favorite cookbook?
Also hard to choose. Right now we have a copy of Ben Shewry’s new book, Origin: The Food of Ben Shewry, in the Culinary Lab. It rules.
Your standard breakfast?
I don’t really eat breakfast, but, if I make it on the weekend, it errs on the English breakfast side of things: poached eggs, tinned beans, potato, tomato, sometimes a breakfast meat. Conversely, I am also a sucker for huevos rancheros.