U.S. Air Force via Wikimedia Commons // Public Domain
U.S. Air Force via Wikimedia Commons // Public Domain

The Chemical Difference Between Red, Yellow, and Green Bell Peppers

U.S. Air Force via Wikimedia Commons // Public Domain
U.S. Air Force via Wikimedia Commons // Public Domain

We’re going to let you in on a little secret: A green bell pepper is just an unripe yellow pepper, which is just an unripe red pepper (though some varieties ripen to yellow, not red). The same is true for green olives, which are unripe black olives, and the seeds inside green beans are just regular beans that haven’t grown up yet. The produce section is apparently full of lies.

The differences in bell pepper taste, appearance, and aroma are not genetic but chemical, as the ripening process releases a series of colorful, delicious natural compounds. 

As the latest great infographic from Compound Interest shows, peppers do go through three distinct traffic-light stages, each with its own chemical components. In its green form, a pepper is especially plant-like, packed with chlorophyll and “green-smelling” aldehydes. Yellow and orange peppers take their color from lutein and beta-carotene, the chemicals responsible for the sunny and orange hues of egg yolks and carrots, respectively. As a pepper reddens, it begins producing more (E)-2-hexenal and (E)-2-hexanol, which give it a sweet, fruity smell.

Want to watch your own peppers change color? You can leave them to ripen on the plant in your vegetable patch, if you've got one, or you can bring them in (or buy them) and store them in a perforated bag or box in a dark, cool room for a few weeks.

Click the infographic to get a more detailed look.

Image credit: Compound Interest // CC BY-ND 4.0

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Just Two Cans of Soda a Day May Double Your Risk of Death From Heart Disease

If you've been stocking your refrigerator full of carbonated corn syrup in anticipation of warmer weather, the American Heart Association has some bad news. The advocacy group on Wednesday released results of research that demonstrate a link between consumption of sugary drinks—including soda, fruit juices, and other sweetened beverages—and an increased risk of dying from heart disease.

Study participants who reported consuming 24 ounces or more of sugary drinks per day had twice the risk of death from coronary artery disease of those who averaged less than 1 ounce daily. There was also an increased risk of death overall, including from other cardiovascular conditions.

The study, led by Emory University professor Jean Welsh, examined data taken from a longitudinal study of 17,930 adults over the age of 45 with no previous history of heart disease, stroke, or diabetes. Researchers followed participants for six years, and examined death records to determine causes. They observed a greater risk of death associated with sugary drinks even when they controlled for other factors, including race, income, education, smoking habits, and physical activity. The study does not show cause and effect, the researchers said, but does illuminate a trend.

The study also noted that while it showed an increased risk of death from heart disease, consumption of sugary foods was not shown to carry similar risk. One possible explanation is that the body metabolizes the sugars differently: Solid foods carry other nutrients, like fat and protein, that slow metabolism, while sugary drinks provide an undiluted influx of carbohydrates that the body must process.

The news will likely prove troublesome for the beverage industry, which has long contended with concerns that sugary drinks contribute to type 2 diabetes and tooth decay. Some cities, including Seattle, have introduced controversial "soda tax" plans that raise the sales tax on the drinks in an effort to discourage consumption.

5 Ways to Define a Sandwich, According to the Law

It’s easy to say what a sandwich is. Grilled cheese? Definitely a sandwich. Bacon, lettuce, and tomato? There’s no question. Things start to get messy when you specify what a sandwich isn’t. Is a hot dog a sandwich? What about a burrito, or an open-faced turkey melt?

The question of sandwich-hood sounds like something a monk might ponder on a mountaintop. But the answer has real-world implications. On several occasions, governments have ruled on the food industry’s right to use the delectable label. Now, Ruth Bader Ginsburg—pop culture icon, scrunchie connoisseur, and Supreme Court Justice—has weighed in on the matter.

When pressed on the hot-button issue as to whether a hot dog is a sandwich while appearing on The Late Show with Stephen Colbert, Ginsburg proved her extreme judiciousness by throwing the question back at Colbert and asking for his definition of sandwich before making a ruling. Her summation? A hot dog fits Colbert's definition of a sandwich, and therefore can be considered one.

While RBG's ruling may not be an official one, it matches Merriam-Webster's bold declaration that a hot dog is a sandwich (even if the Hot Dog Council disagrees). Officially, here’s where the law stands on the great sandwich debate.


Hot dogs are often snagged in the center of the sandwich semantics drama. Despite fitting the description of a food product served on a bread-like product, many sandwich purists insist that hot dogs deserve their own category. California joins Merriam-Webster in declaring that a hot dog is a sandwich nonetheless. The bold word choice appears in the state’s tax law, which mentions “hot dog and hamburger sandwiches” served from “sandwich stands or booths.” Applying the sandwich label to burgers is less controversial, but it’s still worth debating.


When Qdoba threatened to encroach on the territory of a Panera Bread in Shrewsbury, Massachusetts, the owners of the bakery franchise fought back. They claimed the Mexican chain’s arrival would violate their lease agreement with the White City Shopping Center—specifically the clause that prohibits the strip mall from renting to other sandwich restaurants. “We were surprised at the suit because we think it’s common sense that a burrito is not a sandwich,” Jeff Ackerman, owner of the Qdoba franchise group, told The Boston Globe.

The Worcester County Superior Court agreed. When the issue went before the court in 2006, Cambridge chef and food writer Christopher Schlesinger testified against Panera [PDF], saying, “I know of no chef or culinary historian who would call a burrito a sandwich. Indeed, the notion would be absurd to any credible chef or culinary historian.”

Justice Jeffrey A. Locke ruled that Qdoba would be allowed to move into the shopping center citing an entry in Merriam-Webster as the most damning evidence against Panera’s case. “The New Webster Third International Dictionary describes a ‘sandwich’ as ‘two thin pieces of bread, usually buttered, with a thin layer (as of meat, cheese, or savory mixture) spread between them,’” he said. “Under this definition and as dictated by common sense, this court finds that the term ‘sandwich’ is not commonly understood to include burritos, tacos, and quesadillas.”


If you want to know the definition of a certain dish, the officials at the U.S. Department of Agriculture are good people to ask. It’s their job to make sure that the nation’s supply of meat is correctly labeled. When it comes to sandwiches, the agency follows strict criteria. “A sandwich is a meat or poultry filling between two slices of bread, a bun, or a biscuit,” Mark Wheeler, who works in food and safety at the USDA, told NPR. His definition comes from the Food Standards and Labeling Policy Book used by the department (the USDA only covers the “labeling of meat, poultry, and egg products,” while the FDA handles everything else, which is why the USDA's definition excludes things like grilled cheese). Not included under their umbrella of foodstuff served between bread are burritos, wraps, and hot dogs.


The USDA’s definition may not be as simple and elegant as it seems. A sandwich is one thing, but a “sandwich-like product” is different territory. The same labeling policy book Mark Wheeler referred to when describing a sandwich lumps burritos into this vague category. Fajitas “may also be” a sandwich-like product, as long as the strips of meat in question come bundled in a tortilla. Another section of the book lists hot dogs and hamburgers as examples of sandwich-type products when laying out inspection policies for pre-packaged dinners. So is there an example of a meat-wrapped-in-carb dish that doesn’t belong to the sandwich family? Apparently strombolis are where the USDA draws the line. The Food Standards and Labeling Policy Book clearly states the product “is not considered a traditional sandwich” [PDF].


When it comes to sandwiches, New York doesn’t discriminate. In a bulletin outlining the state’s tax policy, a description of what constitutes a sandwich warrants its own subhead. The article reads:

“Sandwiches include cold and hot sandwiches of every kind that are prepared and ready to be eaten, whether made on bread, on bagels, on rolls, in pitas, in wraps, or otherwise, and regardless of the filling or number of layers. A sandwich can be as simple as a buttered bagel or roll, or as elaborate as a six-foot, toasted submarine sandwich.”

It then moves on to examples of taxable sandwiches. The list includes items widely-believed to bear the label, like Reubens, paninis, club sandwiches, and peanut butter and jelly sandwiches. Other entries, like burritos, gyros, open-faced sandwiches, and hot dogs, may cause confusion among diners.