This blog post was written by Will Judson.
This journal article investigates the presence of potentially harmful benzene, trihalomethanes, and formaldehydes in the up and coming brewing industry in China. The production of beer has become a very prominent industry in China over the past decade, and it now has become one of the largest beer producing countries in the world8. However, with most upstart industries in developing countries it is seen that the quantity of the product being produced far outweighs the quality. The research presented within this journal article peers into the idea that Chinese beers contain harmful carcinogens that are added to the beer in the production process. Along with determining what these carcinogens are, the researchers also determine the amount of the particular carcinogens that are present and compare these results to the amount found in the water sources of the area. These particular results will also be compared to the allowance levels of the particular carcinogens released by the World Health Organization (WHO) and other prominent organizations. Benzene in beer is harmful and is listed by International Agency for Research in Cancer (IARC) as a harmful carcinogen7. Although benzene is listed as harmful when consumed by humans, many industries introduce benzene to their product during the packaging and preservation steps. Along with benzene there is a group of chemical contaminants that affect brewing liquor known as trihalomethanes. Trihalomethanes is a group of chemical contaminants that are formed during chlorination when the chlorine reacts with organic acids within untreated water; these include chlorinated hydrocarbons, chlorophenols, chloroform, bromodichloromethane, bromoform, and several pesticides1,4. The most shocking addition to Chinese beer is formaldehyde which is added during the mashing process and is believed to improve the overall clarity and stability of the wort (the liquid extracted during the mashing process that will undergo fermentation)8.
As the scientists strived to determine what contaminants resided in Chinese beers they used several methods and experiments to perform the task of analyzing the beer samples. While testing for harmful benzene within the beer the researchers obtained 84 different beer samples, in which 77 were brewed in China. In order to detect the benzene levels of different beers they used a gas chromatograph and a headspace autosampler. A gas chromatograph is used as an analytical tool to find out how many components are in a mixture. It can also be used to separate small amounts of material3. None of the seven beer brands brewed outside of China contained detectable benzene (the gas chromatographer would not detect benzene levels lower than 1.0 µg/L). However, 7 of the 77 beer brands brewed in china contained benzene, the highest level of benzene detected was 7.1 µg/L while the lowest detected level was 1.9 µg/L with an average level of 4.0 µg/L. As for the detection of trihalomethanes in beer the scientists used a method that was proposed by Anheuser-Bush8. This method once again called for the use of a gas chromatograph and a headspace autosampler which would measure the total amount of trihalomethanes within a beer. The total amount of trihalomethanes is reported as the sum of chloroform, bromodichloromethane, and bromoform8; these numbers were obtained from 107 different beer samples. The maximum level of trihalomethanes found was 5.2 µg/L, with an average of 1.2 µg/L. An interesting aspect of this study is that the scientists also took total trihalomethane levels in the water found in 27 different sites on which several beer brands are brewed. The water obtained from these sites has levels of trihalomethanes ranging from 2.7 µg/L to 46.9 µg/L, with an average of 19.1 µg/L. One water sample even contained 79.3 µg/L of total trihalomethanes. The detection of formaldehyde in beer was done using Solid-phase microextraction (SPME) techniques8. Of the 29 beer samples analyzed, all contained formaldehyde with levels ranging from 0.082 mg/L to 0.356 mg/L. All of the experiments and analysis techniques performed throughout this study were done using the most advanced technology available in determining what contaminants reside within Chinese beer. This study accurately portrays not only what harmful compounds are in Chinese beer, but also the levels that these harmful compounds reach.
In the study of benzene contaminants in beer it was shown that a majority of the samples analyzed did not contain detectable amounts of benzene. All 6 samples of beer that did contain benzene had levels below 10.0 µg/L, which is the limit for benzene in drinking water recommended by the World Health Organization6. After detecting the benzene in the 6 samples of beer, the scientists then set out to determine the cause of harmful benzene within the product. The inclusion of benzene into the final product was thought to occur in the dilution process, however the breweries all showed strict guidelines when it came to the water used in the dilution process8. The traces of benzene were then linked to the carbonation of the beer under the discovery that many Chinese beers have relatively low original gravities (lower alcohol content). These low original gravity levels mean that less carbon dioxide was produced during the fermentation process8. Breweries rely on carbon dioxide to keep their product fresh on the shelves, and the less carbon dioxide produced within the fermentation process means the more carbon dioxide they have to introduce to the product from outside sources. All six breweries that contained detectable benzene had relatively low annual outputs (small and less established breweries) and relatively low original gravities which required them to obtain their carbon dioxide for packaging from outside sources. This carbon dioxide was obtained from less than renowned sources that lacked adequate quality control systems8. It was stated that several brands obtained their carbon dioxide from fertilizer plants8. The fact that breweries obtain their ingredients from fertilizer plants should be alarming to consumers in the Chinese market. But the amount of benzene in beer from these breweries should not deter Chinese consumers from buying beer produced in china simply because the water levels in China most likely contain more benzene. The article also brings up a good point about soft drinks and the amount of carbon dioxide that goes into the production of soft drinks. Soft drinks obtain all of their carbonation from outside sources, and if these sources are the same sources that smaller Chinese breweries obtain their carbon dioxide from, it could pose a major health threat to the consumers.
As far as the results for the analysis of trihalomethanes in beer goes, it was shown that all of the beer samples contained trihalomethanes even if they occurred in very minute amounts. Figure 1 in the journal article shows a very intriguing pattern as it lists the total number of trihalomethanes in a beer sample and plotted it with the beers original gravity. With all of the data plotted on a single graph it is easily seen that beers with the most trihalomethanes typically have a lower original gravity. This lower original gravity was also the culprit in the presence of benzene contaminants in beer. However, trihalomethanes would generally not be found in carbon dioxide sources added to a beer, so there must be a different source that adds these organic contaminants to the final product. It is stated in the article that trihalomethanes are typically boiled off or lost during the boiling process of making the beer8, so the trihalomethanes are coming from a different source. It was also concluded in the paper that the source of these trihalomethanes was the blending liquor added to the product after the fermentation and boiling processes8. The scientists did not present an adequate argument as to why they concluded that the source of the trihalomethanes was the blending liquor added to the product; therefore I have drawn my own conclusion linking the trihalomethanes found in beer to the breweries water supply. A control study performed by the scientists tested the trihalomethane levels in the water sources of 20 different breweries. These locations had levels ranging from 2.7 µg/L to 79.3 µg/L. Figure 2 lists all 20 locations on a graph and shows the contaminants in the water as well as their levels, this is interesting because it gives the reader an idea of what actually was found at these locations. It is stated in the article that it is the brewmaster’s job to ensure that the quality of water received from the local water source meets brewery standards5. However, if these are the same breweries that purchase carbon dioxide for their products from fertilizer plants, I have a hard time believing that these water quality standards are being met. Granted, most of the trihalomethanes found in the water supplies will be boiled off and lost in the production process, but some will always remain in the final product.
As the scientists set out to determine the amount of formaldehyde in beer, they discovered that all 29 samples contained the contaminant to some degree. The scientists were using a very advanced technique to analyze the samples, which made it possible to detect formaldehyde even at the smallest amounts. This raised the question, were breweries in China the only ones who added formaldehyde to their final product? Or was this a trend seen around the world? In the article it was mentioned that a similar study of formaldehyde in beers was done by Donhauser and co-workers2 as they examined beers from Europe using a less advanced method. It was found that 65% of the European beers contained detectable formaldehyde, but the detection level of the method they were using was 0.2 mg/L2. With this detection level many of the Chinese beers tested would have shown no traces of formaldehyde. So the 65% reported by the study of European beers was a flawed number. As shocking as it is, the addition of formaldehyde to beer is a common practice seen around the world. Recently formaldehyde has been listed as a carcinogen8, and studies have shown it to be hazardous to human health when consumed. In saying this, no matter how popular formaldehyde had become as an additive to beer it can no longer be used in the production process. Many breweries now choose a product known as PVPP (polyvinylpyrrolidone) in order to improve the clarity of the wort of beer8. In the article the formaldehyde levels were measured in milligrams per liter instead of micrograms per liter like trihalomethane levels and benzene levels. Seeing this, formaldehyde levels could be the consumer’s greatest concern when purchasing beer.
This article did raise concern about beers being brewed in China’s up and coming industrial society. With harmful contaminants floating around such as benzene, formaldehyde, and the various types of trihalomethanes one can only wonder that the beer that purchase can cause more adverse effects than just a bad hangover the next morning. All of the samples tested throughout this experiment did not exceed WHO drinking water levels, so how harmful are these contaminants in the beer that individuals consume? All of the contaminants found and analyzed were found in very minute levels, in some cases as low as 1 microgram per liter. I believe in order for these contaminants to have adverse effects on one’s body, the person would have to consume large amounts of the breweries product at a time. The mean value for trihalomethane levels in the beers analyzed in this study was 1.2 µg/L, where as the mean value for trihalomethane levels in the water sources sampled was 19.1 µg/L. The water sources have roughly 16 times the amount of trihalomethane levels than the beers being sampled in this experiment. In order for one to be exposed to the same levels of contaminants that are found in local water supplies in China they would have to consume very unhealthy amounts of beer. An individual drinking this amount of beer would see far more health issues related to the consumption of a mass amount of alcohol, rather than the carcinogens found in these beers. I believe this article was very helpful when it came to exposing what contaminants are actually being introduced into the Chinese breweries. The study and experiments were well thought out as they successfully found out what they originally wanted to investigate. However, I do believe that the scientists performing these studies were expecting to find higher numbers of these carcinogens as they analyzed the various beer samples, and so was I. Overall this article portrayed accurate information about the upstart brewing industry in China, and it successfully relayed trustworthy information to the public dealing with the quality of beer being produced.
References
1. Baxter, E.D., The influence of brewing liquor on beer safety and quality. Ferment, 1999, 12(4), 13-18.
2. Donhauser, S., Glas, K., and Walla, G., Detection of formaldehyde in beer. Monatsschrift fűr Brauwissenschaft, 1986, 39(10), 364-368.
3. “Gas Chromatography.” CU Boulder Organic Chemistry Undergraduate Courses. Web. 10 Nov. 2011.
4. Grant, A.P., Liquor quality. Ferment, 1995, 8(4), 252-255.
5. McGarrity, M.J., McRoberts, C., and Fitzpatrick, M., Identification, cause, and prevention of musty off-flavors in beer. Tech. Q. Master brew. Assoc. Am., 2003, 40(1), 44-47.
6. World Health Organization 2001. Guidelines for Drinking Water Quality. World Health Organization, Geneva.
7. World Health Organization International Agency for Research on Cancer: IARC monographs on the evaluation of carcinogenic risks to humans. Supplement 7, 1987, IARC Press: Lyons, pp.120.
8. Wu, Qian-Jun, Hong Lin, Wei Fan, Jian-Jun Dong, and Hua-Lei Chen. “Investigation into Benzene, Trihalomethanes and Formaldehyde in Chinese Lager Beers.” The Institute of Brewing and Distilling 112.4 (2006): 291-94. Print.
