Your phone can now tell you if the milk’s off before you open it.
How good is modern life?
Technology has brought us so many gifts in the past 100 years, like antibiotics (*sob*), washing machines, heart-monitoring wristwatches, hearing aid earbuds, medical advice TikTok and Temu for all your whatever-the-hell-this-is needs:
Here’s another thing we bet you didn’t know you needed: a way to scan milk in the bottle or carton and see whether it’s off, using only the vibration motor and inertial measurement unit in your smartphone.
An enterprising team at UNSW’s computer science and engineering faculty has invented just that, exploiting milk’s changing response to vibration signals as it endures the cruel passage of time.
As bacteria grow, lactate levels increase and glucose decreases, and the colloid suspension that is fresh milk separates into curds, whey and water, with changed density, viscosity, and surface tension.
“VibMilk” captures vibration signals produced by the smartphone motor using the IMU sensor, then uses machine learning algorithms to analyse these signals and classify the spoiling milk at 23 pH levels, corresponding to freshness. pH levels fall from a neutralish 6.6 straight out of the udder to around 4.4 after 75 hours, according to a graph supplied by the team.
“Testing on four common smartphones showed that VibMilk can predict the pH values of milk with an average accuracy of 98.35% and achieved a 100% accuracy for indicating fresh milk,” the press release says.
Nice job!
Why though?
Research lead Professor Wen Hu explains: “You can smell or taste if milk is off, but that requires opening the package. Doing so exposes it to bacteria, and that accelerates spoilage. VibMilk is non-invasive, which means you can test the freshness of the milk without breaking the seal.”
Use-by dates are unreliable, he says, and other non-invasive milk freshness tests require either specialised and costly equipment, a custom cup, or transparent containers – “all factors that limit widespread adoption”, the professor says.
Okay … We still don’t quite get it.
The Back Page is not a passionate milk drinker, so may not be the best TMR staff member to comment on the importance of this work, but is still familiar with milk-related behaviour.
The team says VibMilk will prevent milk wastage – but if consumers (following that widespread adoption) detect off milk in the fridge at the supermarket, that milk will still be wasted. If they bring it home, they’ll use it until it’s finished or gone off, probably not throw it out just because the unreliable use-by date tells them to. But either way, by the time it’s home and open, the non-invasiveness of the testing method is irrelevant.
They say VibMilk will prevent ill health from people drinking off milk – which most people in the position to use this technology wouldn’t do, given our aforementioned olfactory ability to tell when milk is spoiled.
“Outbreaks of food-borne germs continue to rank among the leading causes of illnesses and death globally,” the team begin their paper – published in the IEEE Internet of Things Journal – attributing 420,000 deaths a year worldwide to consumption of contaminated and rotting food.
That is truly awful, but we suspect the populations most affected here are not those most likely to be zapping a carton of milk with a smartphone in the fridge at their local providore.
The rich west is probably in more danger of succumbing to food fads like drinking unpasteurised milk, which causes an average of 10 outbreaks of food-borne illness a year in the US.
Finally, if every consumer (widespread adoption, remember) scans all the available milk at the shop, won’t that result in compromised refrigeration and either more spoilage or unnecessary energy use?
At this point we agree we’re thinking about this too much. But we do believe that a more candid answer to the question “Why did you make this?” might be “Because we could.”
To arguably more pressing questions: seriously, anyone, what is this supposed to be?
Send fresh, pasteurised and homogenised story tips to penny@medicalrepublic.com.au.
