That caffeine in your drink -- is it really 'natural?'

Maik A. Jochmann, Ph.D., and colleagues point to the growing consumer preference for foods and beverages that contain only natural ingredients. Coffee, tea, colas, energy drinks and other caffeine-containing drinks are the most popular beverages in the world. Food regulatory agencies require that caffeine be listed on package labels, but do not require an indication of whether the caffeine is from natural or synthetic sources. The scientists set out to develop a faster, simpler method for categorizing caffeine's origins.

In the study, they describe use of a technique called stable-isotope analysis to differentiate between natural and synthetic caffeine. The test makes use of differences in the kinds of carbon isotopes – slight variations of the same element – found in caffeine made by plants and caffeine made in labs with petroleum-derived molecular building blocks. Their analysis, which takes as little as 15 minutes, found four products that contained synthetic caffeine, despite a "natural" label.

More information: Caffeine in Your Drink: Natural or Synthetic? Anal. Chem., Article ASAP. DOI: 10.1021/ac203197d

Abstract
Owing to possible adulteration and health concerns, it is important to discriminate between natural and synthetic food ingredients. A new method for compound-specific isotope analysis (CSIA) by coupling high-temperature reversed-phase liquid chromatography to isotope ratio mass spectrometry (HT-RPLC/IRMS) was developed for discrimination of natural and synthetic caffeine contained in all types of drinks. The analytical parameters such as stationary phase, column inner diameter, and column temperature were optimized for the separation of caffeine directly from drinks (without extraction). On the basis of the carbon isotope analysis of 42 natural caffeine samples including coffee beans, tea leaves, guaraná powder, and maté leaves, and 20 synthetic caffeine samples from different sources by high-temperature reversed-phase liquid chromatography coupled to isotope ratio mass spectrometry, it is concluded that there are two distinguishable groups of caffeine ?13C-values: one between -25 and -32‰ for natural caffeine, and the other between -33 and -38‰ for synthetic caffeine. Isotope analysis by HT-RPLC/IRMS has been applied to identify the caffeine source in 38 drinks. Four mislabeled products were detected due to added but nonlabeled synthetic caffeine with ?13C-values lower than -33‰. This work is the first application of HT-RPLC/IRMS to real-world food samples, which showed several advantages: simple sample preparation (only dilution), high throughput, long-term column stability, and high precision of ?13C-value. Thus, HT-RPLC/IRMS can be a very promising tool in stable isotope analysis of nonvolatile compounds.

Provided by American Chemical Society (news : web)

That caffeine in your drink -- is it really 'natural?'

 That caffeine in your tea, energy drink or other beverage -- is it really natural? Scientists are reporting successful use for the first time of a simpler and faster method for answering that question. Their report appears in the American Chemical Society (ACS) journal Analytical Chemistry.

Maik A. Jochmann, Ph.D., and colleagues point to the growing consumer preference for foods and beverages that contain only natural ingredients. Coffee, tea, colas, energy drinks and other caffeine-containing drinks are the most popular beverages in the world. Food regulatory agencies require that caffeine be listed on package labels, but do not require an indication of whether the caffeine is from natural or synthetic sources. The scientists set out to develop a faster, simpler method for categorizing caffeine's origins.

In the study, they describe use of a technique called stable-isotope analysis to differentiate between natural and synthetic caffeine. The test makes use of differences in the kinds of carbon isotopes -- slight variations of the same element -- found in caffeine made by plants and caffeine made in labs with petroleum-derived molecular building blocks. Their analysis, which takes as little as 15 minutes, found four products that contained synthetic caffeine, despite a "natural" label.

The authors acknowledge funding from the German Federal Ministry of Economics and Technology and the German Research Foundation.

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Journal Reference:

Lijun Zhang, Dorothea M. Kujawinski, Eugen Federherr, Torsten C. Schmidt, Maik A. Jochmann. Caffeine in Your Drink: Natural or Synthetic? Analytical Chemistry, 2012; : 120306094119006 DOI: 10.1021/ac203197d

Chemistry professor links feces and caffeine

The researchers took water samples from streams, brooks and storm sewer outfall pipes that collect storm waters across the Island of Montreal, and analyzed them for caffeine, fecal coliforms, and a third suspected indicator, carbamazepine. Shockingly, all the samples contained various concentrations of these contaminants, which would suggest that contamination is widespread in urban environments. Carbamazepine is an anti-seizure drug which is also increasingly used for various psychiatric treatments, and the researchers thought it might be a useful indicator because it degrades very slowly. However, unlike with caffeine, no correlation was found.

Caffeine degrades within a few weeks to 2-3 months in the environment and is very widely consumed. The presence of caffeine is also a sure indicator of human sewage contamination, as agriculture and industry do not tend to release caffeine into the environment. The team also noted that the data suggest that Montreal's storm water collection system is widely contaminated by domestic sewers. On the other hand, the researchers observed high levels of fecal coliforms but little or no caffeine in some of the samples, which they attribute to urban wildlife. "This data reveals that any water sample containing more than the equivalent of ten cups of coffee diluted in an Olympic-size swimming pool is definitely contaminated with fecal coliforms," Sauvé said. "A caffeine sampling program would be relatively easy to implement and might provide a useful tool to identify sanitary contamination sources and help reduce surface water contamination within an urban watershed."

More information: "Fecal coliforms, caffeine and carbamazepine in stormwater collection systems in a large urban area" was published online in Chemosphere on November 8, 2011.

Provided by University of Montreal (news : web)

New evidence that caffeine is a healthful antioxidant in coffee

 

Scientists are reporting an in-depth analysis of how the caffeine in coffee, tea, and other foods seems to protect against conditions such as Alzheimer's disease and heart disease on the most fundamental levels. The report, which describes the chemistry behind caffeine's antioxidant effects, appears in ACS' Journal of Physical Chemistry B.

Annia Galano and Jorge Rafael León-Carmona describe evidence suggesting that coffee is one of the richest sources of healthful antioxidants in the average person's diet. Some of the newest research points to caffeine (also present in tea, cocoa, and other foods) as the source of powerful antioxidant effects that may help protect people from Alzheimer's and other diseases. However, scientists know little about exactly how caffeine works in scavenging the so-called free radicals that have damaging effects in the body. And those few studies sometimes have reached contradictory conclusions.

In an effort to bolster scientific knowledge about caffeine, they present detailed theoretical calculations on caffeine's interactions with free radicals. Their theoretical conclusions show "excellent" consistency with the results that other scientists have report from animal and other experiments, bolstering the likelihood that caffeine is, indeed, a source of healthful antioxidant activity in coffee.

More information: “Is Caffeine a Good Scavenger of Oxygenated Free Radicals?” Journal of Physical Chemistry B. DOI: 10.1021/jp201383y

Abstract
The reactions of caffeine (CAF) with different reactive oxygen species (ROS) have been studied using density functional theory. Five mechanisms of reaction have been considered, namely, radical adduct formation (RAF), hydrogen atom transfer (HAT), single electron transfer (SET), sequential electron proton transfer (SEPT), and proton coupled electron transfer (PCET). The SET, SEPT, and PCET mechanisms have been ruled out for the reactions of CAF with •OH, O2•-, ROO•, and RO• radicals. It was found that caffeine is inefficient for directly scavenging O2•- and •OOCH3 radicals and most likely other alkyl peroxyl radicals. The overall reactivity of CAF toward •OH was found to be diffusion-controlled, regardless of the polarity of the environment, supporting the excellent •OH scavenging activity of CAF. On the other hand, it is predicted to be a modest scavenger of •OCH3, and probably of other alkoxyl radicals, and a poor scavenger of HOO•. RAF has been identified as the main mechanism involved in the direct ROS scavenging activity of CAF. The excellent agreement with the available experimental data supports the reliability of the present calculations.

Provided by American Chemical Society (news : web)