bananas – BIG

Ice cream is the perfect summer treat. Except when it’s melting over your hands. Luckily, there’s potential good news for those of us tired of dealing with sticky fingers. Two separate groups of researchers have recently released papers on additives that could be included in ice cream recipes to keep your treats colder longer.

Stop the drip

A chemical engineer in Columbia named Jorge Velásquez Cock has been working on finding ways to recycle banana tree waste. A thick stalk attaches each bunch of bananas to the trunk of the banana plant. The cellulose-rich woody stalks are usually thrown out.

Velásquez Cock’s research developed a method to extract the cellulose from the stalks and added it to ice cream. In controlled lab conditions, the extract prevented ice cream delayed the melting by 20 minutes at 20°C.

The cellulose extraction process is too time-consuming and costly to be commercially viable for now, but Velásquez Cock and his colleagues are looking at ways to make it more efficient.

Freezer burn no more

There’s one place where your ice cream is melting that you might not expect: inside your freezer. Every time you open the door, warm air rushes in. Even when you leave the door shut, the temperature eventually starts to rise which is why you periodically hear the motor kick in.

As the inside of the freezer warms, ice crystals in your ice cream start to melt. Each time the crystals refreeze they grow slightly larger. Large ice crystals are what gives ice cream that gritty, freezer-burned mouthfeel.

Ice cream makers often add stabilizers, such as guar or locust bean gum, to the mix. A group of researchers at the University of Tennessee was looking for a better stabilizer and settled on cellulose nanocrystals (CNCs for short). CNCs are microscopic strand of cellulose.

Their initial conclusions, reported in the American Chemical Society’s Biomacromoclecules, showed that the CNC additive could significantly delay and inhibit the growth of ice crystals. Again, more research has to be done before CNCs end up in your dessert.

In the meantime, the experts at Ben & Jerry’s have several to tips on how to prevent freezer burn including stashing it at the back or bottom of the freezer underneath other items to shelter it from the warmer air.

Of course, there is an alternative solution: scarf down your cone as fast as possible and finish the whole container in one sitting. If you do that, you may want to read our Q&A in our August issue about how to cure ice cream headaches!

The stink of skunk on the family dog, the stench of burnt campfire popcorn, and the odour of a septic tank pump-out—there are undoubtedly some smells that can easily skyrocket a cottage owner’s stress levels. But humans aren’t the only members of the animal kingdom to get stink stress. Researchers from McGill University have uncovered an unusual stink-induced stressor for a certain critter: it turns out that male mice are stressed by the smell of bananas.

“Stress affects almost every biological and and behavioural phenomena,” says the co-author of the study, Dr. Jeffrey Mogil, a professor in the department of psychology at McGill University and the E. P. Taylor Chair in pain studies.

Animals behave differently depending on whether their stress levels are high or low, says Mogil. For scientists whose research includes lab animals like mice, an unknown environmental stressor could end up skewing the results of their experiment.

“I think it’s really important to try to figure out all the stressors and all the confounds we can find so research in the future is better,” says Mogil.

It was students from McGill University who first noticed that male mice were behaving oddly in the laboratory. “I’ve learned over the years that when my students notice something we should follow it up,” says Mogil.

A series of experiments showed that the male mice were reacting to the presence of pregnant and lactating female mice also housed in the laboratory. The main offender for the stress turned out to be a chemical in the urine of the female mice called n-pentyl-acetate.

Male mice are known to kill the offspring of other mice. The researchers think that the n-pentyl-acetate is being used by pregnant and lactating female mice to send an aggressive and stinky message to males: back off.

“This is a new form of social signalling that’s never been described before,” says Mogil. “Mice signal to each other all the time through smell, but there are very few examples of females signalling to males on a topic that doesn’t involve sex. The message here is that there might be a fight.”

N-pentyl-acetate happens to be very similar in structure to isopentyl acetate, the chemical that gives bananas their signature odour. The researchers found that banana oil produced the same stress reaction in male mice as the female urine. “The fact that it’s banana smell that seems to be the most important chemo-signal is funny,” says Mogil.

If you’re hoping the researchers stumbled upon the secret key to halting rodent infestations, think again. The smell only works on male mice, points out Mogil—which isn’t much use if females come around. “We’re certainly not suggesting that anyone try to control mice in their house with bananas,” he says. Best to save your bananas for banana bread.