EDUARDO CESAR“What is it you’re studying? Cachaça. What? Ah, so you must be a boozer.” This type of mocking dialogue in response to a common question within the scientific world is received with a certain amount of complacency by the researchers at the Aguardiente Chemical Development Laboratory (LDQA), of the São Carlos Chemical Institute of the University of Sao Paulo (USP). They know the importance of the studies that they are involved with to analyze the quality and classify the various nuances of this genuinely national drink, recognized abroad, almost like football and Brazilian music, mainly through the famous caipirinha drink. The country produces around 2 billion liters and exports have reached 11 million liters, numbers that transform the cachaça into the third distilled drink most consumed in the world, behind the Korean Soju, made from rice, wheat and sweet potato, also known as Shochu in Japan, and vodka.
Established some 12 years ago by professor Douglas Wagner Franco, the laboratory is searching to chemically investigate cachaça. During 2004 the group collaborated, through chemical confirmation, about the differences between rum and cachaça in the United States. Stubbornly, the two drinks made from sugarcane but via different processes and with contrasting aromas and tastes, were considered to be the same thing in that country. The situation changed with a study presented in the Journal of Agricultural and Food Chemistry, an important publication in the food and beverage area. From there, cachaça could display itself on the label as being a typically Brazilian drink. Afterwards, the researchers continued their work to better understand the organic and mineral composition of cachaça. Now they have developed methods and systems of classification and are collaborating with the drink’s continual improvement. As well as learning about what exists in a cachaça sample, knowing all of the phenomena related to the production and maturing, the researchers have developed techniques that indicate, for example, if the drink was produced in small artisan stills or in a large distillery, if the sugarcane used was burned or not, because, if burned, the result can indicate the presence of components harmful to the consumer’s health.
“We also analyze the minimum quantity of components demanded by legislation and we informed the manufacturers, principally helping the small producer who plants sugarcane, harvests, ferments the juice, distills and bottles” explains the post-doctorate student, Dr. Daniel Rodrigues Cardoso. Many associations and producer cooperatives are looking for quality via laboratory analyses. Within a public policy project financed by FAPESP, and without any cost to the producer, they are carrying out analyses, indicating solutions and complementing their work with lectures by group members.
“The legislation has changed a lot for the producers in Brazil, imposing limits on mineral and chemical compounds. Recently Canada and Germany have gone on to demand certificates showing the presence level of various components, among them ethyl carbamate, a carcinogenic substance that can also be found in foods, as well as the levels of methanol and other types of alcohols” says Franco. The presence of copper, an ancient concern, is no longer important, although it contributes to the formation of carbamate. “The levels of copper in our cachaça are, in general, within the parameters demanded by legislation” says Franco. During 2005, in an analysis of 108 collected samples in the state of São Paulo, the largest national producer, 75% of the cachaças complied with the legislation, with levels below 5 milligrams per liter. In 2003, during a similar analysis, the index reached 60%. In relation to carbamide, during that same year, the analysis showed that 51% of the samples where below the stipulated legislation limit. Samples collected in 2005 indicate that 70% possess levels below the limit. “This set of data shows a growing concern by the producers to improve the quality of their drink” says Cardoso. Although some components present in cachaça can bring up concern, they cannot be eliminated during the production process. “The problem is that if some components were to be eliminated, the drink’s personality would also disappear” suggests Franco.
To collaborate mainly with the quality of the small producers’ drink is an extensive and long term pursuit. “In spite of having generated a large data bank, we’re still only scratching the surface in the analysis and there are few laboratories in Brazil that are doing this type of study” says Cardoso. Even at the Ministry of Agriculture, which has the responsibility to fiscally review the national drinks, there is no infrastructure for all of the analyses that the legislation and importers demand. “We carry out analyses, but we don’t have the power to veto and to say “don’t sell” only to counsel and make suggestions for the regulating of quality standards” says Franco.
Many of the studies and methods developed in the laboratories, have gone on to be used by producers, cooperatives and associations, and will be published in magazines directed towards the sector and in scientific publications. They are methods that should contribute to an improved performance by the near 30,000 cachaças producers in the country, according to the Ministry of Development, Industry and Commerce, responsible for more than 5,000 brand names, many of them penetrating into the competitive and demanding market of Brazilian sophisticated bars and restaurants as well as those abroad.
Variations in the drink
A large part of the studies carried out by the group started with the cachaça collection taken from the producers themselves during 2005 in the state of Sao Paulo, in which, of the 108 samples, only 27 were from major producers. “We analyzed 35 variables, such as the presence of copper, iron, methanol, ketone, aldehyde and acetic acid.” The objective was to establish a chemical profile of cachaça and a data bank that would be transposed into specific software, called chemometrics , resulting in graphs that would distinguish the drinks samples coming from artisan stills, with copper piping, and those of fractionating columns, present in major distilleries, made from stainless steel. According to the master’s degree student, Roni Vicente Reche, on the graph it became evident that the cachaças distilled via the column are similar among themselves in relation to those from the artisan stills, with lesser variation in their chemical composition. They position themselves closely one to the other in relation to components and rarely step outside of the levels demanded by legislation. Starting from this analysis, they have concluded that ethyl carbamate and benzaldehyde are the most important compounds in the industrial group of cachaças.
In the artisan cachaças the variation in their chemical compounds is greater. The most important are: formaldehyde, 5-hydroxy-methyl-furfural (5HMF), acetic acid, and propionaldehyde. The 5HMF is found in low concentrations, but, if it is at a high level, it means that pieces of sugarcane had been present during the distillation process. With this data in hand, the researchers constructed a model for distinguishing between artisan cachaças and those produced using a fractionating column with 97% certainty.
Other components are under the focal eye of the researchers and are as yet not controlled by Brazilian legislation. These are the polycyclic aromatic hydrocarbons (PAHs), mainly present when the sugarcane is burned before harvesting. Scientific studies have already found the presence of these compounds in whisky, rum and in grappa, for example. Hydrocarbon compounds such as benzo-(alpha)-pyrene and antracene are potential carcinogenics even worse than ethyl carbamate. In order to identify the presence of these compounds in cachaças, the researchers made use of the collected samples and presented a questionnaire to the producers in order to know if they had or had not burned their sugarcane.
After examining 136 samples via molecular analysis chromatography, the researchers traced out a profile of the cachaça coming from the burned and unburned sugarcane. The study showed that the drink produced from the burned sugarcane had an average level of 21 micrograms per liter of PAHs, whilst those that had not been burned gave levels ten times lower. Of the 136 samples, 28 were produced with burned sugarcane and 108 unburned sugarcane. As a result of these studies, the researchers developed a methodology that differentiates the cachaça produced from the two types. “The percentage of certainty is 95%” advised the researcher Carlos Alexandre Galinaro.
One of the studies that will still take up a lot of the researchers’ time is the analysis of the Brazilian woods used in the construction of barrels for the maturing of the cachaça in place of the traditional ones made from oak, a tree that originated in the northern hemisphere. On remaining stored for long periods in order to mature – more than one year by Brazilian legislation ” the drink thickens, gains aroma, taste and a more attractive color. Matured cachaças have a yellowish tone whilst those that are not matured are transparent.
The identification of substances extracted during this process has led to the development of an analytical method for quantifying and for the determination of the natural chemical compounds of different woods that are incorporated into the cachaça, always in comparison with those of oak (Quercus sp.), the tree widely used throughout the world for maturing alcoholic drinks such as whisky, wine and brandy. By reason of their elevated cost, many times these barrels are used by Brazilian producers after they have been discarded by whisky producers in Scotland, for example.
In Sao Carlos, between 15 to 20 types of wood are being compared to that of oak. Armed with a multiple stage mass spectrometer, capable of verifying, for example, the structure and molecular mass of chemical compounds, the researchers are analyzing substances called polyphenols extracted from the wood by the drink. “Polyphenols such as catechin are beneficial to health” says Cardoso. They contribute to inhibiting the deposition process of fat in the arteries. Cardoso pointed towards the best option, up until now, as being the construction of barrels from the amendoim tree (Pterogyne sp.), a native of the Atlantic Rainforest, which reaches a height of 10 to 15 meters, and has a trunk diameter of between 40 to 60 centimeters. “It has sensorial properties (taste, aroma, color) similar to that of oak and possesses better antioxidant activity.”
It is believed that the polyphenol compounds are linked to the wood’s cellular defense mechanisms, and their presence depends on their geographical origin and on climatic factors. In order to carry out the studies, the researchers requested certified woods, provided by the Technology Research Institute (IPT) and by the Wood Structures Laboratory of the Sao Carlos Engineering School (EESC) of USP. The oak, which served for comparisons, was provided by Strathclyde University, in Scotland, wood with Czech, Polish, French and Scottish origin. “We want to identify chemical markers for the wood species and for the maturing period” says Cardoso. One of the woods analyzed by the group, namely canella sassafras (Ocotea pretiosa), showed itself to be problematic. “The wood from this tree has carcinogenic compounds such as saphrol and presented pro-oxidant properties, accelerating the process of atherosclerosis.” Other Brazilian woods that are under study include the chestnut (Castanea sp.), the ipê (Tabebuia chrysotricaha), the jatoba (Hymenaea courbaril) and the laurel-canella (Aniba parviflora).
“The work of classification that we’re finalizing is going to be important in a few years time with refinement and the objective of improving the drink’s quality” says Franco. “This will happen principally in the environment of exports, because those being imported are coming under a higher and higher demand. Some ten years ago nobody had heard of ethyl carbamide.” According to professor Franco, only professor Fernando Valadarez Novaes, from USP’s Luiz de Queiroz Upper school of Agriculture (Esalq), had studied and discussed the theme. “Today it’s necessary to show that the cachaça (even in tests carried out as a counter test in the importing country) doesn’t possess this substance at levels higher than those established through legislation.”
The physical-chemical aspects of cachaça: formation of flakes, ethyl carbamate, maturation and potential antioxidant
Regular Line of Research Assistance
Douglas Wagner Franco – USP
R$ 145,633.75 and US$ 170,885.72 (FAPESP)
Quality improvement of cachaça and the preparation of a quality standard
Public Policies Research Program
Douglas Wagner Franco – USP
InvestmentR$ 113,076.00 and US$ 21,300.00 (FAPESP)