Oat: Substrate for malted cereal fermented beverages

Technical Session 19: Outside the Box Session
Alicia Muñoz Insa, Lehrstuhl für Brau- und Getränketechnologie, Technische Universität München, Freising, Germany
Co-author(s): Martina Gastl, Martin Zarnkow, and Thomas Becker, Lehrstuhl für Brau- und Getränketechnologie, Technische Universität München, Freising, Germany

ABSTRACT: Fermentation of food is a worldwide technique applied for preservation of a wide range of raw materials. It also provides a natural way to increase the nutritive value and appearance of the raw material and leads to a general enhancement in the shelf-life, taste, and aroma of the final product by destroying undesirable components. During cereal fermentation with lactic acid bacteria, synthesis or degradation of some components, such as phytine or vitamins, and increase in digestibility provides higher nutritional quality to the final product. Also the formation and removal of several volatile compounds contributes to acceptability. In recent years, interest in oat as a food ingredient for beverage production has increased due to its high dietary fiber content and health benefits. Oat soluble dietary fibers are not digested in the human intestine and pass through to the colon, where they are available as prebiotic materials for microbial fermentation. Moreover oat exerts antioxidant activity. But, compared to other foods such as milk, cereals, and its by-products it sometimes has an inferior or poor nutritional value and sensory properties. Although oat is a suitable substrate for fermentation, through malting and mashing the availability of some components, acceptability, and nutritional value, not only for lactic acid bacteria (or yeast) but also for the human body, increases. This project attempted to produce high quality wort from malted oat to ensure good fermentation and to increase the availability, acceptability, and nutritional value of the final beverage. The influence during malting, mashing, and fermenting parameters on final product quality was investigated. Finally, regimes tailored to the physical and chemical properties of oat are proposed. Every criteria was based on malting and brewing standard values. At the final stage of this research, four LAB species were selected to independently ferment oat wort. As a result, four different beverages with different taste profiles were developed. Generally the produced novel beverages were characterized as sour refreshments.

Alicia Muñoz Insa studied at the Technical University of Madrid, Spain, and carried out her diploma thesis at the Technical University of Munich. In 2009 she began working as a Ph.D. student at the Institute of Brewing and Beverage Technology (TUM) under the supervision of Thomas Becker. Her research is currently focused on field alternative cereal-based beverages.