If you’ve seen even one advertisement for premium coffee, then you’ve probably heard someone going on about “100 percent pure Arabica beans” … but does the coffee really only contain Arabicas? A new method makes it quicker, cheaper and easier to find out.

Arabica beans are generally considered to be better tasting than cheaper Robusta beans, which trade at as little as half the price. Combined with the fact that Robustas are higher-yielding and easier to grow, this makes it tempting for some companies to surreptitiously cut their Arabica-based coffee with a bit of Robusta.

Traditionally, the only way of checking the purity of Arabica coffee involves testing samples for the presence of a chemical known as 16-O-methylcafestol (16-OMC) – it has long been thought that the compound is present in Robusta beans, but not in Arabica. Unfortunately, samples need to be sent off to a lab for analysis, and processing of those samples takes approximately three days.

Now, however, researchers from Britain’s Quadram Institute have discovered that a Pulsar benchtop NMR (nuclear magnetic resonance) spectrometer made by Oxford Instruments can do the same thing on-site in just 30 minutes. The device uses radio waves and magnetic fields to obtain information about the molecular composition of a sample, and can reportedly be easily operated by non-specialists. It’s previously been utilized to detect horse meat in ground beef.

In lab tests, it was used to analyze 60 samples of supposedly 100-percent Arabica coffees gathered from 11 different coffee-growing countries and regions around the world. While 90 percent of those samples were deemed to be pure, the rest had high enough 16-OMC levels to indicate fraud.

The spectrometer can detect Robusta concentrations as low as 1 percent in blended coffees. In fact, it turned out to be sensitive enough to reveal that even Arabica beans do contain small amounts of 16-OMC. Therefore, the testing procedure had to be adapted to allow for a threshold amount of the chemical, which will be detected regardless of whether or not Robusta is present.

A paper on the research was recently published in the journal Food Chemistry.

Sources: Quadram Institute, Oxford Instruments

source: http://www.newatlas.com / NewAtlas.com / Home> Science / by Ben Coxworth / May 17th, 2018

Tune in tonight on PBS NewsHour where Miles O’Brien will look at the hazards and history of lead as part of his Leading Edge series.

Needless to say, humans have a coffee obsession.

Last year, global coffee consumption weighed in at 10 million tons — or one and half Great Pyramids worth of beans ground into caffeinated oblivion. Now, a lab at the Italian Institute of Technology wants to put those discarded grounds to good use.

The team has engineered a coffee grounds-infused foam that removes hazardous metals, like lead, from water. Though still in its prototype phase, this foam might be able to clear the worst levels of lead contamination found in places like Flint, Michigan, within a few hours.

“The proposed method is cheaper [than current large-scale filtration systems], since it uses principally costless waste,” said IIT physicist Despina Fragouli who led the project. “and more sustainable compared to other systems, where synthetic materials are used.”

The idea isn’t entirely new. Scientists have known for years that coffee contains chemical groups — called carboxylates — that stick to metals. Early attempts at this water remediation concept tried smashing the coffee grounds into a fine powder, which was then mixed into lead-tainted water. The toxic metals bind the powder, and together, they are filtered out of the water. But this procedure is a bit redundant — you need a filter for a filter.

Fragouli and her colleagues simplified this process by chemically infusing the coffee powder onto a elastic foam. The final spongy foam is 60 to 70 percent coffee by weight.

“Both the coffee and the heavy metal ions are entrapped in the foam,” Fragouli said of her findings published in ACS Sustainable Chemistry and Engineering. “Therefore, no additional procedures are required for the removal of the [coffee] adsorbents and the pollutants from the water.”

So, a water official would simply pull the foam from the water to take out the metal toxins. The rate of removal depends on how much lead is in the water. If Fragouli’s team started with water containing nine parts per million of lead — 360 times higher than most common amount found during the Flint water crisis — the foam could remove a third of the contamination in 30 minutes.

Though promising, Fragouli said more research is needed to determine if the foam can obtain lead and mercury levels appropriate for drinking, especially with gunky water flowing through real-world pipes. So far, the sole field test occurred with wastewater from the IIT’s chemistry department, which contained a mixture of metal ions.

“The results show that the metal ions of interest can be effectively removed,” Fragouli said.

source: http://www.pbs.org / PBS Newshour / Home> The Run Down> Science / by Nsikan Akpan / September 28th, 2016