Guia Covid-19
Imprimir Republish

Technology Beverages

Light-infused beer

A light source inserted during fermentation accelerates yeast metabolism and increases production

Chris Stein / getty images

Recent icons of the world of electronics, found on TV and computer screens, or used to replace ordinary light bulbs, LEDs have just gained a new and unusual role. They now also accelerate the fermentation stage of beer production by reducing the time required for the process by 15% to 20% without compromising the quality of the beverage. This occurs when sources of LEDs, light emitting diodes made with semiconductor material in the form of devices similar to flashlights, are submerged in vats where the yeast, Saccharomyces cerevisiae, is nourished by carbohydrates from barley malt to produce alcohol, carbon dioxide and then beer. This technique was developed at the University of São Paulo’s São Carlos Institute of Physics (IFSC-USP) and is now in use at the Kirchen Microbrewery in São Carlos.

The USP researchers discovered that under certain wavelengths characteristic of the red and infrared spectrum bands, yeast metabolism tends to increase. “Light enhances the cell membrane permeability of Saccharomyces and this promotes the exchange between the internal and external yeast environment. So it metabolizes the malt sugar more quickly and expels ethanol and CO2 from the cellular environment,” says Éverton Estracanholli, one of the researchers. He got the idea of using light in the beer brewing process while pursuing his doctorate at IFSC; he developed his research with Professor Vanderlei Bagnato, his thesis advisor, and Professor Igor Policarpov. The aim was to use light to measure the amount of carbohydrates in wort samples during the fermentation stage.

Wort is a mixture of water and malt, or other grains depending on the type of beer, which are mixed and heated to form a sweetened liquor. After separation of the grains, hops (the inflorescence of an aromatic plant in the form of pellets) are added to the wort, which gives the beverage its bitterness and part of the aroma, and the mixture is boiled. The next step is fermentation in which yeast is added. “The presence of light on yeast cells facilitates the exchange of electrons in the Krebs cycle, which is a sequence of chemical reactions associated with the respiratory process of cells. As the electrons flow from one chain to the next, the chain reaction accelerates,” says Estracanholli.

“The interaction with light excites the electrons in certain types of molecules, which alters the biological process at the molecular level,” says Bagnato. “The chemical reaction that occurs within the wort involves large transfers of electrons from certain molecules to others, and light increases the speed of these transfers,” he explains. “But not just any light will do, and one must determine the parameters, because some doses and light bands kill yeast. Our study identified the colors [wavelengths], the light intensity used, the dose provided and the amount of lighting time needed,” explains Estracanholli.

Photostimulation in biological systems is a known phenomenon. The use of lasers and LEDs in yeasts such as Saccharomyces or Endomyces magnusii, or bacteria such as Escherichia coli, have been shown to stimulate the respiratory activity of these microorganisms and thus promote cell reproduction. “But so far we have found no citations in scientific literature about the use of electromagnetic radiation [visible light or infrared] to accelerate fermentation processes, whether alcoholic or non-alcoholic,” he says. The new process has led to a patent filing by the three researchers who are listed as the inventors and USP listed as the sponsor. Estracanholli, a physicist whose hobby of making beer at home was inherited from his father, decided to use LEDs in his home production which later became the Kirchen Microbrewery. As a student of the subject, he won an award for the best beer of the Irish Red Ale type — a beer with a dark red color and a dry, very pronounced malt flavor — in the 2012 edition of the National Competition of the Acervas, regional associations of craft brewers.

Another experiment conducted at IFSC, with a patent pending by the same three researchers and USP, involves applying analytical techniques to monitor and measure the carbohydrate and alcohol concentration within a short span of time in the production of beer. The technique they developed measures the amount of alcohol and sugar present in the wort during fermentation. “It acts as the reflected light is absorbed by a sample of beer or any industrial food, such as tomato paste, for example.” The researchers also believe it can be used in the sugar-alcohol industry not only to monitor ethanol production but also to check the amount of sugar present in the cane while still in the field. The light emission on the stalk and analysis of the spectral response, which is the portion of light absorbed by the material, and the resulting information processed by a computer in a few seconds, can show the amount of time needed to cut the cane. The first prototypes of these devices will be launched later this year.

050-055_Cerveja_204“During the preparation of Estracanholli’s doctoral thesis, he demonstrated the feasibility of real-time monitoring of alcohol and carbohydrates. Now, through an agreement between USP and the company he started, he will be able to move ahead in showing the functionality of this concept. In the pilot production he is launching, which is different from a small laboratory prototype, the idea is to create a device that can be used in the manufacture of various types of beverages,” says Bagnato. “The objective is to use fiber optic beams to carry light to the material being analyzed and collect the components of light that were not absorbed. This makes it possible to do real-time monitoring of the production process,” he says. The system also uses artificial neural networks, which are programs based on biological neurons capable of learning by example using computational and mathematical interconnections.

In real time
Among the potential fermentation processes to be analyzed with arrays of LEDs in bands of visible and infrared light is the fermentation of sugarcane juice to obtain ethanol fuel or distilled products such as rum, as well as vinegars and derivatives. Specifically in the production of beer, a new real-time analysis system on the production line will measure the major carbohydrates present in the fermentation of the beverage wort, such as glucose, maltose, maltotriose and dextrins, in addition to ethanol.

The current industrial practice worldwide is to collect samples on the production line for subsequent analysis in the laboratory, which is almost always within the plant itself. “Performing these analyses on the production line is almost never done,” says Bagnato. For Professor Waldemar Venturini Filho, of Universidade Estadual Paulista (Unesp) School of Agricultural Sciences in the city of Botucatu, who has studied and worked with beer fermentation for over 20 years — and also served on Estracanholli’s doctoral review committee — the new equipment for real-time production analysis is fantastic and will primarily aid in controlling alcohol fermentation, which is considered the heart of beer processing. “It’s a promising system and can even be used in academia in studies of the fermentation process,” says Venturini.

Above, diffusers on the tips of the LEDs illuminate all of the liquid. On the right, an experiment at Kirchen Microbrewery in São Carlos

EDUARDO CESARAbove, diffusers on the tips of the LEDs illuminate all of the liquid. On the right, an experiment at Kirchen Microbrewery in São CarlosEDUARDO CESAR

University support
Professor Bagnato believes the project, a USP-Kirchen partnership, may lead to an innovative product. “Who knows, in the future, combining real-time analysis with photonic stimulation could produce a totally different way of promoting and controlling fermentation. Thus, the light injected into the system may become a new parameter in the area,” he says. “My philosophy is that nascent companies must have the support of the laboratories that produced them, in this case IFSC. Estracanholli’s company may not immediately have all the infrastructure we have here at USP. Thus, it is essential that we collaborate, making our equipment available so that he can perform the characterizations and other studies that would otherwise prove difficult. This is the best way to generate a spin-off in academia,” says Bagnato, who is also the general coordinator of the USP Innovation Agency.

Control and photonic stimulation equipment will be used, especially in the beginning, by microbreweries, a growing segment in Brazil led by Brazilian consumer interest and greater acceptance of premium or gourmet beers. They are more expensive but made ​​with finer ingredients, higher percentages of malt and special hops, and have a longer maturation period, the final stage of beer fermentation, responsible for harmonizing the flavor and aroma of the beverage. Brazil has about 180 microbreweries, in addition to 30 midsize breweries with more than 60 brands. Even combined they are still a long way from the production of large breweries such as Ambev – owner of the Brahma, Antarctica, Bohemia and Skol brands – Schincariol and Heineken, which also owns the Kaiser and Bavaria brands. “Our future market in terms of the equipment with the LEDs to accelerate fermentation as well as doing real time analysis of production is geared mainly toward microbreweries, but will also reach units of big industry,” predicts Estracanholli.

By knowing the potential of LEDs in stimulating yeast during the fermentation process, André Oliveira, a partner in the Mão na Roda Microbrewery in Botucatu, after two years in the market, says it would be great to have this equipment because production could grow without the need to increase the size of the brewery. “I believe that for large companies the use of LEDs in fermentation could also be a good innovation,” says Estracanholli. “There is no similar equipment on the market.”

Microbreweries producing special or premium beers may be the first breweries to experiment with LEDs in production

Eduardo CesarMicrobreweries producing special or premium beers may be the first breweries to experiment with LEDs in productionEduardo Cesar

According to the report on Global Beer Consumption by Country in 2010, by the Kirin Institute of Food and Lifestyle, a Japanese beverage company which in 2011 bought the Brazilian company Schincariol, Brazil is the world’s third largest producer of beer, with 12.1 billion liters produced in 2010, trailing China, 44.6 billion, and the United States, 24.1 billion, and ahead of Russia and Germany.

In per-capita consumption of beer, Brazil ranks 27th with 65 liters per capita, while the leaders are the Czech Republic with 131 liters, followed by Germany with 106, Austria, 105, and Ireland, 103. A leading producer, China, is in 49th place with 31 liters in per-capita consumption. According to Kirin, beer production grew in Brazil by 16% compared to 2009. Total beer sales in Brazil reached R$62 billion in 2010.

Tropical fruits and honey

In addition to the beverage’s presence in academic centers, other avenues have been opened in the relationship between beer and academia. Studies have focused on finding innovative formulations and adding new brewing adjuncts, the name given to ingredients added to replace part of the barley malt, decrease production costs and create a lighter beverage. Large brewers use rice and corn for this purpose, which appear on labels as unmalted cereals. In Brazil, the latest avenue of research in academia into brewing adjuncts comes from Bahia. A group of researchers at the State University of Feira de Santana (UEFS) is studying the production of beer using fruit found in the semiarid northeast, such as umbu, hog-plum and cocoa, among others. “We want to take advantage of the high concentration of carbohydrates found in these fruits and also the aromatic compounds that can increase beer production ​​in this region of Brazil,” says Professor Giovani Brandão Carvalho, the group’s coordinator.

Banana, hog-plum, umbu-hog-plum and black rice are among the ingredients that can replace part of the barley malt in beer; they are the subject of academic research

EDUARDO CESAR / FÁBIO COLOMBINI / IACBanana, hog-plum, umbu-hog-plum and black rice are among the ingredients that can replace part of the barley malt in beer; they are the subject of academic researchEDUARDO CESAR / FÁBIO COLOMBINI / IAC

In order to study these blends, he set up a mini brewery in the UEFS Fermentation Laboratory within the Support Program for Emerging Centers (Pronem) with funds from the State of Bahia Research Foundation and the National Council for Scientific and Technological Development (CNPq). “We want to bring microbreweries here and strengthen family farming in the region,” says Carvalho. His studies on beer began with his PhD at the Lorena School of Engineering (USP). Under the guidance of Professor João Batista de Almeida e Silva, he developed a Pilsen lager with banana juice as an adjunct to the wort. In addition to a slightly fruity taste, the beverage has a high potassium content. “It has 600 mg of potassium versus 200 mg in one liter of common Pilsen lager,” says Carvalho. “We published two papers in international scientific journals, and now it is being manufactured in Costa Rica,” he says, further remarking that it was naive not to patent the process. Next time he will be more cognizant of intellectual property. Professor Almeida e Silva believes this type of beer would be ideal if it had up to 1% alcohol, because it could serve as a nutrient replacement when consumed as a sports drink. He has also experimented with the use of black rice, from the Campinas Institute of Agronomy (IAC), as an adjunct for the beer. “Our intention was to take advantage of the up to 25% loss during processing of the black rice, which breaks easily and has no market value. The result was a Pilsen-type lager that was a bit dark, almost brown, whose process has been patented,” he says.

In a project with Amazonas State University (UEA), he has had good results with the seed of the pupunha palm tree, which is widely used for hearts of palm. “The seed is little used and has a high starch content,” he says. Professor Almeida e Silva’s current experiments include the use of pine nuts and sugarcane juice, also as adjuncts.

Another experiment, which was carried out by Professor Waldemar Venturini Filho of Unesp Botucatu, resulted in a beer with honey in its formulation. Under Brazilian law, in order for a beverage to be considered beer, it must contain at least 55% malt. Thus, among the most common beers, extra special and premium, defined by maturation time and increasing alcohol content, only the latter had the most pronounced flavor and aroma of honey,” says Venturini Filho. “Industrial breweries require that adjuncts, such as corn and rice, be neutral and not provide flavor and aroma to the beer. In microbreweries the adjuncts such as fruits, honey and others, are used to enrich the aroma and flavor of the beer.”

Projects
1. Encouraging the biophotonics innovation project (nº 1998/14270-8); Grant Mechanism Research, Innovation and Dissemination Center (RIDC), Optics and Photonics Research Center at São Carlos; Coordinator Vanderlei Bagnato (USP); Investment R$ 180,000.00 for the subproject only which lasted three years (FAPESP)
2. Honey as malt adjunct in beer production (nº 2011/21823-0); Grant Mechanism Regular Line of Research Project Award; Coordinator Waldemar Venturini Filho – Unesp; Investment R$ 17,921.50 and US$ 13,290.00 (FAPESP)
3. Black rice IAC 600 (Oryza sativa) as a malt adjunct in high gravity Pilsen brewing (nº 2007/01347-3); Grant Mechanism Regular Line of Research Project Award; Coordinator João Batista de Almeida e Silva (USP); Investment R$ 102,818.27 and US$ 26,708.00 (FAPESP).

Republish