Almost 2 out of every 10 people suffer from stomach irritation when they drink coffee so finding a solution to the problem could help coffee makers reach a wider audience.
Although stomach friendly coffees are already on supermarket shelves, scientists at the University of Vienna and the Technische Universitat Munchen said there is a lack of understanding of the irritancy problem.
“The problem is that studies have not verified the stomach irritating potential of coffee or its components, until now,” said Veronika Somoza, from the University of Vienna. “Manufacturers currently make 'stomach friendly' coffees by processing raw coffee beans with steam or solvents intended to reduce levels of the irritants. But their effectiveness is unclear.”
Somoza therefore teamed up with Thomas Hoffmann from the Technische Universitat Munchen in Germany to determine more clearly what is causing irritancy in coffee.
The two scientists exposed cultures of human stomach cells to a variety of different coffee preparations, including regular, dark-roast, mild, decaffeinated, and stomach-friendly.
Guilty elements
Reporting their findings at the National Meeting of the American Chemical Society this week, they identified several substances that appeared to trigger chemical changes associated with increased acid production.
“Our data shows, for the first time, that caffeine, catechols and N-alkanoly-5-hydroxytryptamides are those coffee components that stimulate molecular mechanisms of stomach acid secretion in human stomach cells,” said Somoza.
Stomach friendly products currently on the market are made by processing raw coffee beans with steam or solvents to reduce the presence of irritants. As most of the ingredients identified in the latest research are removed by steam or solvent treatment, the results appeared to provide evidence supporting the efficacy of the current batch of stomach friendly coffees.
But the scientists behind the research said the results did throw up some unexpected results that could help manufacturers create a new generation of stomach-friendly brews with the rich taste and swell of regular coffee.
Stomach friendly ingredient
They said one of the coffee components identified in the work, N-methylpyridium (NMP), seems to block the ability of the stomach cells to produce hydrochloric acid and could provide a way to reduce or avoid stomach irritation.
As NMP is generated only upon roasting and not found in raw coffee beans, it is counter intuitively espresso, French roast, and other dark-roasted coffees that may be easier on the stomach.
“Since NMP is generated upon roasting, dark-roast coffees contain high amounts of this stomach friendly coffee ingredient,” Hofmann and Somoza said. “Now, there is hope for a good morning start with a freshly brewed cup of optimized stomach friendly coffee.”
On the back of this research, the scientists are testing different varieties of raw coffee beans and different roasting methods in an effort to increase levels of NMP and make a better stomach-friendly coffee. The intention is to test out the new coffee drink among volunteers later in 2010.