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Caramel Apples Linked to Deadly Listeria Infection

Halloween is nearly upon us, and that means parties, parades, pillowcases, and paranoia about people trying to poison our children. The annual media-fueled rumors of poisoned candy and razor blade–studded apples are unfounded, but there is one treat you might want to treat with extra caution: caramel apples.

From November 2014 to February 2015, at least 35 people from 12 states were infected with listeriosis. Of those people, 90 percent said they’d eaten prepackaged caramel apples before they got sick. A new study explains how it happened.

Listeriosis is an infection is caused by the bacterium Listeria monocytogenes. It mostly affects the elderly, pregnant women, and people with compromised immune systems, but in rare cases people without these risk factors can become infected. Early symptoms of listeriosis include fever, muscle aches, and diarrhea, but the infection often spreads from the gut into the rest of the body.

Once it becomes invasive, listeriosis can be deadly. All but one of the 35 people infected in last winter’s outbreak were hospitalized, and seven died, at least three of them as a direct result of the infection. Alarmed by the news, three brands of prepackaged caramel apples and one apple producer issued recalls.

But no one knew how the bacteria got into the apples in the first place. Under normal circumstances, caramel is too sludgy, and apples too acidic, for bacteria to grow. In a journal article published this week in mBio, researchers from the University of Wisconsin-Madison's Food Research Institute report two conditions that made the outbreak possible.

Bacteria that lands on the outside of an apple has usually reached a dead end. But inserting a stick into the apple breaks the skin and creates a tiny puddle of juice on the surface of the fruit. Smothering that sugary puddle in a layer of caramel then creates the perfect environment for bacterial growth.

The researchers also found that temperature plays a big role. They made caramel apples with and without sticks and swabbed them all with Listeria bacteria. Half of the apples went into the fridge and half were left on the counter. After three days at room temperature, the bacterial colonies on apples with sticks had multiplied by one thousand. Refrigerated apples with sticks were able to fend off bacteria for a week before succumbing. No bacteria at all grew on the chilled apples without sticks.

The solution here is pretty clear, say the researchers. You don’t have to give up on caramel apples. Buy them fresh, keep them in the fridge, and eat them within a few days. 

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A Rare Apple Lisa 1 Computer Is Up for Auction on eBay
Dave Jones, Flickr // CC BY 2.0
Dave Jones, Flickr // CC BY 2.0

For superfans of vintage Apple products, a working Apple Lisa 1 is the holy grail of collector's items. First released in 1983, the pioneering computer (the first to feature a graphic interface and a mouse) was a commercial failure and only sold 100,000 units, very few of which survived to the present day. But an eBay seller is offering up the super-rare opportunity to own one, as DesignTAXI reports.

The computer in question, selling for more than $55,000 as of January 8, is in mint condition. According to the listing, it has only been turned on a few times.

A Lisa 1 computer
professorinschubert, eBay

As you can see in the video below, everything seems to be in working order.

The seller estimates that there are only 20 to 100 Lisa 1s left in the world. And even for a Lisa 1, this one is a rare machine. Lisa computers, reportedly named after Steve Jobs’s daughter (though there have been some other theories about the name), were the only machines Apple released with its doomed Twiggy disk drives—a faulty format that turned out to be incredibly unreliable, leading to the product’s downfall. Apple then released the Lisa 2 with standard 3.5-inch floppy disk drives, offering customers free upgrades for their Lisa 1 Twiggy drives.

Since most customers jumped at the chance to make their $10,000 computer ($24,700 in today's dollars) run properly, Lisas that still have their original Twiggy drives are incredibly hard to find. The Lisa 1 on sale still has its twin Twiggy drives though, and they work, at least as well as the drives ever worked.

Whether the seller will actually get his $55,000 is questionable. In 2010, a similar Lisa 1 sold for just $15,000. But the model seems to have gained a lot of value since then, since one sold for $50,000 in November 2017.

[h/t DesignTAXI]

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Big Questions
Why Do Honeycrisp Apples Cost So Much?
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Apples to apples is no longer a valid comparison. As gastronomic writer Sarah Jampel at Food52 has observed, shoppers who prefer a premium fruit experience by opting for Honeycrisp apples can pay up to four times as much as they would for other varieties. When did Granny Smiths become the RC Cola to Honeycrisp’s Coke?

According to Jampel, the answer invokes the old law of supply and demand. There’s plenty of demand for the apple, but prices get engorged when there isn't enough to go around.

The scarcity is a result of the Honeycrisp’s eccentric nature. Introduced commercially in 1991 after being invented by University of Minnesota scientist David Bedford, who cross-pollinated seeds to create a more durable and winter-resistant apple, the Honeycrisp tree demands very specific soil and maintenance requirements. The fruit can ripen at various times, necessitating more frequent harvests; the skin is thin and delicate, so they must be trimmed off by hand. Many of the trees are so delicate they require a trellis [PDF] to support their branches.

All the extra labor means more time and money—the latter of which is passed along to the consumer.

Growers who didn’t anticipate the surging popularity of Honeycrisps were also caught off-guard. As trees can take up to six years to bear enough fruit for commercial purposes, the number of trees currently producing isn’t really proportionate to the level of demand.

That will change as more are planted, although it might be a little while before the Honeycrisp proves to be on the same economic footing as its Red Delicious counterpart. Before you celebrate a cheaper version, remember that growers looking to feed the market might opt to grow the apple in less-than-perfect conditions that could affect its famously crunchy taste. Enjoy it while you can.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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