Cynthia Almaguer (1), Thomas Becker (1), Martina Gastl (1); (1) Technische Universität München – Lehrstuhl für Brau- und Getränketechnologie, Freising, Germany

Malt and Grains

The beverage industry has been experiencing some major changes. Consumers are requesting beverage diversification as a response to recent changes in trends and consumption habits. Brewers are expected to react to this shift and create innovative beverages to meet the demands. These tailored drinks should still deliver the nutritional benefits of the raw materials used. To satisfy these market-driven demands, brewers are looking for new diversification strategies. Brewers could benefit from the combination of germination (malting) and fermentation to enhance the nutritional and sensory quality of grain (cereal/pseudocereal) based beverages. Malting involves the controlled germination and subsequent drying of grains. By varying the processing parameters during germination and drying, a variety of malts with different attributes is obtained. The brewer’s main requirement of malt is as a source of substrate, enzymes, and color. Suitable manipulation of malting conditions could positively enhance the processing (milling, mashing, filtering) properties as well as the flavor profile of the raw materials. Fermentation is the oldest method of food preservation; it can naturally enhance the flavor properties and health benefits of the raw materials used. During fermentation synthesis or degradation reactions occur, leading to the formation or decomposition of compounds. Proper understanding of the by-product formation mechanisms is essential for the brewer to benefit from the available brewing technologies. For centuries, the main brewing cereal has been barley; in some countries, wheat and sorghum are also commonly used. Other grains rich in carbohydrates could also be suitable for brewing. For brewing it is important to use high-quality raw materials. These should not only be easy to brew with but also deliver desirable flavor profiles to the finished beverage. In this study, different raw materials and microorganisms were screened. In an attempt to understand the impact of the malting process on the malt properties, three raw materials (barley, rye, and quinoa) were investigated and compared. First, the influence of three malting parameters (temperature, germination time, and moisture) on the analytical and processing properties of the produced malts was investigated. Subsequently, the standard malting parameters, for each grain, were selected based on the processing properties (i.e., extract = max; viscosity = min). A standard malt was produced for each of the raw materials investigated. The aroma profile of the produced standard malts was determined, and the key aroma compounds were identified. Changes in the key aroma compounds were monitored over the course of the production process. Fermentable substrates were produced with the standard malts and fermented with different microorganisms. The flavor stability of the produced beverages was analyzed. By comparing the sensory and analytical profiles of the produced beverages it is possible to determine the impact of the raw material and microorganism on the flavor profile. The collected data is useful as it discloses the processing parameters needed to deliver positive aromas and flavors to beverages.

In 2008, Cynthia Almaguer completed her B.S. degree in biochemical engineering at Jacobs University in Bremen. She then started her master’s degree in a collaborative project between the Institute of Brewing and Beverage Technology (Prof. Thomas Becker) in TUM-Weihenstephan and the Department of Food and Nutritional Sciences (Prof. Elke Arendt) in University College Cork. Her research project aimed to understand and reveal the taste and antimicrobial contributions of the hop hard resins in beer. Her hop project was funded by the Barth-Haas Group. Cynthia is the 2010 recipient of the InBev-Baillet Latour Fund Scholarship for Brewing and Malting to fund her Ph.D. work. A significant portion of her current research activities are directed toward beverage development and the investigation and understanding of malt aroma.