Food Scientists have Discovered a Surprising Principle behind Good Recipes

Given the number of ingredients that humans eat, the total number of ways to combine them is on the order of 10 to the 15th power. And yet the actual number of recipes we eat is around one million—a small fraction of the total. That strongly suggests an organizing principle that, in recipe terms, sorts the wheat from the chaff.

So an ongoing challenge for food scientists is to discover laws that govern flavor combinations and use them to create new recipes yet to be experienced by human taste buds.

Today, Tiago Simas at Telefonica Research in Barcelona, Spain, and a few pals say they have discovered an important principle of flavor combination by studying foods of different cultures. This new insight could help create novel recipes.

The background to this group’s discovery is the hypothesis of food pairing developed by the chefs Francois Benzi and Heston Blumenthal. At first glance, foods such as chocolate and blue cheese can seem as different as it is possible for foods to be. And yet, these foods share 73 different flavor molecules.

That’s why at certain high-end restaurants, you’ll sometimes find blue cheese and chocolate in the same dishes. The thinking is that when ingredients contain the same flavor molecules, they can be successfully paired. The idea is that shared flavors help blend ingredients more effectively. Food pairing immediately suggests a novel way to create new recipes, which is why it rapidly gained influence among a certain breed of gastronomist.

Then in 2011, a curious piece of research revealed that food pairing was only part of the explanation behind successful recipes. In this work, a team at Harvard University in Cambridge, Massachusetts, analyzed the network of links between ingredients in recipes from all over the world. In this network, ingredients are nodes in a web, linked when they share flavor molecules.

This approach turned the food-pairing hypothesis on its head. When recipes from North America and Western Europe are analyzed in this way, the networks reveal that food pairing is an important factor. But when the team analyzed recipes from East Asia (Korea and Japan, for example), they found exactly the opposite. These cuisines seem to combine the very foods that do not share flavor ingredients. Clearly the food-pairing hypothesis is just part of a bigger picture and in need of a serious upgrade.

Enter Simas and his colleagues. These guys have looked a little harder into the web of flavors behind recipes and discovered a deeper principle at work. The basic idea is that when two ingredients do not share flavors, the team look for a third ingredient with flavors in common with each of the first pair. In this way, they were able to identify flavor chains and explore how recipes in different parts of the world use them.

For example, apricot and whiskey do not share flavors with each other but do have flavors in common with tomato. This creates a flavor chain that links all three ingredients, making them suitable to be used in the same recipe.

The team call this food bridging. They define it as “the ability to connect a pair of ingredients, that may or may not have a direct connection, through a path of non-repeating ingredients.”

This has an important impact on recipes. While food pairing intensifies flavor by mixing ingredients in a recipe with similar chemical compounds, food bridging smooths any contrast between ingredients, say Simas and co.

So what role does food bridging play in recipes from different cultures? To find out, Simas and co examined the flavor networks of cuisines from various parts of world and then analyzed the respective roles of food pairing and food bridging in each cuisine.

In Latin America, for example, recipes exploit both food pairing and food bridging, while East Asian food seems to avoid both principles. Southeast Asian cuisines such as Thai and Vietnamese seem to rely only on food bridging, while North American and Western European food use only food pairing.

That’s interesting work that extends the principles behind the way we create recipes. Indeed, it reveals that food pairing is really a special case of food bridging in which the number of nodes in the flavor chain is 0.

A better understanding of these principles should help chefs create new recipes in specific styles. But it is by no means the be-all and end-all of cooking. Successful recipes have a wide range of different parameters in addition to flavor. There is the texture of the food, its temperature, its mouth feel, and its color, to name just a few.

Food bridging can certainly help with new recipes. But a truly universal tool for recipe creation will need to be much broader to incorporate these other factors into its model. That will require significant work.

But step by step, food scientists are learning how humans prune the list of all possible combinations of food to produce the combinations we actually end up eating.

Source: MIT Technology Review


Better Dieting Through Chemistry

Arianne Cohen wrote . . . . . .

First, the shake: At 950 calories, 61 grams of fat, 20g of protein, and 75g of sugars in just 14 ounces of fluid, it’s the centerpiece of the starter kit for Habit LLC, a new individualized nutrition company. It’s also a beast. Even tackling it after a 10-hour fast, as instructed, I have a hard time getting it all down.

Joshua Anthony, founding chief science officer at Habit and one of the shake’s architects, urges me to persevere. “It’s a lot of shake, because it’s designed to be a food challenge,” he says. “Your body has to respond to the overload—the whole process of digestion, absorption, and distribution of those nutrients. How your body manages that gives us important insights about how your body is functioning today.”

Habit aims to be the 23andMe of your metabolism. After I finish the shake, I take samples of my blood periodically over the next two hours and send them back to Habit’s lab in Nashville, along with three swabs of DNA from the inside of my cheek. Within four weeks, I’ll receive a personalized nutrition plan based on my body chemistry and have a coaching session by phone with a dietitian, all for $299. Three additional coaching sessions can be had for $150.

The company was started by Neil Grimmer, co-founder and chairman of Plum Organics, which makes those now ubiquitous baby food pouches. A former triathlete, he developed “CEO disease” during his eight years at the helm of Plum, he says, gaining 50 pounds from “too much coffee and not enough healthy food.” In 2013, shortly after Campbell Soup Co. acquired Plum, he shed the weight with the help of individualized attention from scientists and doctors he’d worked with at the company. This, it occurred to him, might be something others would be interested in.

“When you create a highly personalized business model,” he says, “you can start to wrap additional products and services around it catering to the individual”—say, a meal delivery service, which Habit operates in the Bay Area; a nationwide rollout to major metropolitan areas is planned for the next few months. (The company is currently limiting the shipping of its test kits to the Bay Area; sign up at Habit’s website to be notified when it starts shipping to your city.)

The personalized nutrition market is particularly ripe right now, says Marion Nestle, a molecular biologist and professor of nutrition and food studies at New York University—although most academics are dubious. “All these venture capital companies are just dying to get involved in some sort of food enterprise, because diet is hard for people, and there are people who will love this,” she says. Campbell’s certainly thinks so: It’s backing Habit to the tune of $32 million.

When my results arrive, I find that Habit has deemed me a “protein seeker,” in need of a 35 percent protein diet. I share this with Nestle, who expresses some skepticism. Average protein intake, she says, is about 15 percent, and it’s hard to get higher than that without supplements. Habit doesn’t disclose the algorithm it uses to make its analyses, nor has it published any peer-reviewed research on the efficacy of its dietary prescriptions, so it’s not clear which of the 60 biometric markers the company tests for triggered the advice. I ask Nestle if Habit’s diet recommendations are trustworthy. “They might be, but how would you know?” she says with a sigh. “I’m sure it’s based on something.”

Anthony says that as the size of Habit’s data sets increases, the company will begin to publish research, beginning with a paper he’s planning to present at the Experimental Biology conference in April about nutritional shake composition. (I could provide some customer input.) Transparency, he says, is “super important to us.” Perhaps the current lack thereof is just a little growing pain.

Source: Bloomberg

What’s Behind the Durian Fruit’s Notorious Stench

Most people who have tried durian either love it or hate it. The fruit’s yellowish flesh is sweet and custard-like, but it comes with an overpowering stench of garbage. Scientists studying the unique fruit have now analyzed a set of 20 stinky and fruity chemical ingredients and found that a mere two compounds can re-create the overall smell. Their findings appear in ACS’ Journal of Agricultural and Food Chemistry.

Native to southeast Asia – where the fruit is considered a delicacy, but also banned from some public spaces due to its odor — its appeal has spread to Westerners who relish trying distinct foods from around the world. Scientists interested in the fruit have identified several compounds that contribute to its smell, which has been said to reek of gym socks, garbage and rotting meat. Curious to better understand the complex scent, Martin Steinhaus and colleagues parsed the odor compounds further.

The researchers calculated the “odor activity values” of 19 of the durian’s smelly compounds to see which ones were the most potent. Among the strongest were compounds that smelled of fruit, rotten onion and roasted onion. These were followed by chemicals with strong notes of cabbage and sulfur. Further experimentation found that putting just two specific compounds together — fruity ethyl (2S)-2-methylbutanoate and oniony 1-(ethylsulfanyl)ethanethiol — effectively resembled the fruit’s entire set of odoriferous and fragrant compounds.

The study was published in the Journal of Agricultural and Food Chemistry.

Source: American Chemical Society

Video: Can I Eat Foods Past the Expiration Day?

Watch video at You Tube (4:16 minutes) . . . . .

Grapefruit And Salt: The Science Behind This Unlikely Power Couple

Nadia Berenstein wrote . . . . .

Grapefruit’s bitterness can make it hard to love. Indeed, people often smother it in sugar just to get it down. And yet Americans were once urged to sweeten it with salt.

Ad campaigns from the first and second world wars tried to convince us that “Grapefruit Tastes Sweeter With Salt!” as one 1946 ad for Morton’s in Life magazine put it. The pairing, these ads swore, enhanced the flavor.

In our candy-crushed world, these curious culinary time capsules raise the question: Does salt really make grapefruit taste sweeter? And if this practice was once common, why do few people seem to eat grapefruit this way today?

Turns out, grapefruit and salt did have a history together. But, like a sham romance between co-stars dreamed up by Hollywood publicity departments to boost studio revenues, the pairing of the two in midcentury advertisements seems to have largely been manufactured buzz, hyped by companies with an interest in increasing sales of both products.

Still, this doesn’t mean the chemistry between salt and grapefruit isn’t real. It is, and there’s science to prove it.

The origins of our grapefruit habit

Grapefruits are relatively new to this earth, a hybrid formed from the spontaneous union of two foreign transplants — the Javanese pumelo and the East Asian sweet orange — in Barbados in the middle of the 18th century. First grown commercially in Florida at the end of the 19th century, grapefruit quickly went from being a novelty to being a daily necessity and made fortunes for farmers.

But how to eat it? When new kinds of foods like grapefruit become available, consumers have to figure out what to make of them.

In 1911, an Iowa woman wrote in to the “The Housemother’s Exchange,” a national advice column, to recommend salting grapefruits.

Early 20th century cookbooks and recipes in magazines offered an abundance of ways to use grapefruits in sweet confections, as well as in savory-sweet salads. But the most common option was the one that’s still familiar to us today — at breakfast, chilled, sliced in half, sprinkled with sugar and (optionally) crowned with a bright-red candied cherry.

Even then, though, salted grapefruit had its cheerleaders. In 1911, an Iowa woman calling herself “Gude Wife” wrote in to the “The Housemother’s Exchange,” a national advice column, to recommend salting grapefruits. “Salt neutralizes the bitter taste as well as the acidity,” she advised. Others wrote in to back up this endorsement. “I think you will find that many Southerners always salt their grapefruit,” wrote “M.B.L.” from Philadelphia. “I am sure that if you once try it you will agree with me that it is good.” In fact, salting fruit remains a regional practice alive and well in the South.

Go salty for Uncle Sam

But when World War I disrupted the global sugar supply chain, causing sugar shortages and skyrocketing prices, grapefruit sales plummeted. Americans were apparently reluctant to eat the fruit if they couldn’t drown out its pungency with sugar.

Panicked, the Florida Citrus Exchange, in an effort to boost sales, launched a national advertising campaign in 1919 to convince Americans that grapefruit “need no sugar, and never should have much.” After the sugar crisis ended, so did the campaign. But when World War II came along, and sugar once again became scarce, salt and grapefruit’s high-profile romance was rekindled — this time by salt manufacturers.

“Vitamin-rich Grapefruit — a ‘Victory Food Special’ — is one of the fruits Uncle Sam advises you to eat,” explained one 1943 ad from Morton’s Salt.

Ads like this made an overt appeal to patriotic sentiments. Eating grapefruit with salt was a way civilians could support the war effort, both by consuming nutritious, domestically grown food, and by limiting their use of rationed sugar. The campaign proved so successful that it continued into the 1950s, long after rationing had ended.

The science behind adding salt for sweetness

Even as salt-makers boasted about the taste-enhancing effects of salt on grapefruit, they were at a loss to explain just why the combination worked.

It wasn’t until the mid-1990s that Gary Beauchamp and Paul Breslin at the Monell Chemical Senses Center in Philadelphia began to unravel the complex, dynamic process through which salt transforms and enhances flavor. By testing the interaction between three taste sensations — salty, bitter and sweet — they found that salt increased the perception of sweetness by diminishing our ability to taste bitterness.

Beauchamp, now emeritus director of Monell, explains that this is because of the ions in the salt, which block many of the receptors on our tongues that detect bitterness.

But would reducing bitterness make something taste sweeter? Our sense of taste doesn’t just play out on the surface of our tongues. Our brains receive signals about what we eat from our mouths, noses, eyes, ears and skin, integrating and interpreting these different messages to produce the complex, multisensory experience that we know as flavor. There is strong evidence that, at this cognitive level, bitterness and sweetness inhibit each other. In other words, the more bitter something tastes, the less sweet we perceive it to be, and vice versa.

Grapefruit is rich in bitter-tasting plant compounds, especially one called naringin. By diminishing our tongue’s ability to sense naringin and other bitter compounds, salt also produces a secondary cognitive effect, which we perceive as “a relative bump in sweetness,” according to Breslin, a professor of nutrition at Rutgers University.

Something else might be going on, too, he says. Salt changes the chemistry of water. In a watery food like grapefruit, the addition of salt makes it easier for volatile molecules — the chemicals responsible for odor — to launch themselves into the air, where we can breathe them in and smell them, intensifying our experience of the fragrance of the fruit. So that enhanced scent might heighten our enjoyment as well.

But there’s much we still don’t know about how salt affects flavor, Beauchamp and Breslin both stress. “Of all the taste mechanisms,” Beauchamp says, “salt has been the most intractable — the most difficult to understand. It is still not fully understood.”

Yet other cultures have long embraced the beauty of pairing salt and fruit.

In Mexican and border cuisines, it is common to douse fruits (especially mango) with a combination of salt, chili powder and lime. Similarly, salting fruit like guava or, say, an unripe mango is common practice in India. Thai prik-kab-klua combines salt with the heat of fresh red chilies and sugar, and is served on tart fruits. Chinese li hing powder, a puckery mauve mixture based on salted, pickled dried plums, is often sprinkled on apples and pineapples.

This ain’t your grandma’s grapefruit

So why does the practice remain relatively uncommon in the U.S.?

In the case of grapefruit, the explanation may lie not with the salt, but with the fruit. We are eating different kinds of grapefruit than Americans were eating in the 1940s and 1950s. Generally speaking, as the 20th century progressed, grapefruits became redder, sweeter and more completely seedless.

Currently, about three-quarters of the grapefruits that we eat are red. Redder grapefruits contain less naringin, and therefore taste less bitter. This means that there is less of an incentive to curb bitterness with a dash of salt.

There may be another reason. Between 1950 and 2000, more and more processed foods got a boost in sweetness from high-fructose corn syrup and other refined sweeteners. So adding sugar may have increasingly seemed like the right solution to many domestic culinary quandaries.

Ripe for a reunion?

Since the turn of the millennium, however, the use of caloric sweeteners has steadily declined. Perhaps years of public health warnings about the consequences of excess sugar consumption are starting to change attitudes toward sweetness. Meanwhile, new federal government regulations requiring manufacturers to disclose added sugars on labels are driving food companies to reformulate their products.

In other words, is this the perfect moment for grapefruit and salt to get back together? With the Brangelina breakup, we could all use a new power couple to look up to.

Source: npr