Food Biotechnology Research Group
Functional cultures help reduce additives in food and allow the development of innovative foods from by-product streams.
The Food Biotechnology research group examines desirable microorganisms in food, from the identification of suitable microbial strains to carrying out food application tests.
We combine applied and basic research, focusing on a broad range of microbially-formed bioactive substances, such as antimicrobial, texture influencing, nutritionally significant or aroma-active metabolites.
Using tailor-made, high-throughput screening, we investigate microbial strains in relation to the formation of bioactive metabolites. Ultimately, the desired activity of interesting candidates as well as their influence on fermentation and product quality is tested in food. These challenge tests are an important tool, especially in the field of antimicrobial protective cultures.
We perform safety checks as part of the development of functional food cultures, such as the identification of microbial strains, the testing of antibiotic resistance or the formation of biogenic amines.
The primary objective of our research activities is to improve the quality of food by means of functional cultures, a reduction in food grade additives and the development of novel foods from by-product streams (avoiding food waste).
The compilation of a continuously expanding collection of microbial strains from spontaneous food fermentations and environmental samples is at the heart of our research. The collection, which comprises mainly lactic acid bacteria, has over 10,000 isolates, including acetic acid bacteria, yeasts and adverse or pathogenic germs such as mould or listeria, which are used as target organisms for antimicrobial screening and challenge tests.
Many of our research projects are carried out in cooperation with partners from industry and science.
Our research is focused on the following three key topics:
We work with sourdough and other grain-based fermentations, such as by-products from grain processing and develop functional cultures that form bioactive metabolites with antifungal, texture influencing, nutritionally rich or aroma-active properties. In this way, we can produce baked goods and other innovative cereal-based products that are virtually additive-free, and in line with today's consumer trends and demands.
We examine the entire post-harvest processing of cocoa and its influence on the quality of fermented, dried beans, and finally, the resulting chocolate. We do this by monitoring microbial biodiversity and its influence on post-harvest processing, while also taking into account, chemical, physical and sensory parameters with the aim of identifying interrelationships and applying them in optimization strategies. Such optimization ranges from simple modifications in traditional post-harvest processes to the application of cultures that form bioactive metabolites. In our projects, we work closely with producers and research institutes in cocoa bean producing countries, particularly in Honduras, Bolivia, Ecuador and Brazil.
In order to optimally exploit the effects of protective cultures in food, we investigate the antimicrobial activities responsible for these effects. We examine the formation of antifungal metabolites, the interactions between antifungal lactic acid bacteria and moulds, and the binding and degradation of mycotoxins. In addition to examining antifungal activity, we are also engaged in the detection of known anti-Listeria bacteriocins such as nisin and pediocin as well as the investigation of new types of bacteriocins. The findings of our basic research are then channelled back into the application of protective cultures in food, allowing targeted optimization strategies to be developed.
André, Amandine; Freimüller Leischtfeld, Susette; Mischler, Sandra; Hecht, Katrin; Stäheli, Luca; Rüegg, Ramona; Kinner, Mathias; Buller, Rebecca; Chetschik, Irene; Miescher Schwenninger, Susanne; Müller, Nadina,
20th ICC Conference, Vienna, Austria, 5-7 July 2022.
Streule, Stefanie; Freimüller Leischtfeld, Susette; Miescher Schwenninger, Susanne,
10. Runder Tisch Kakao, Hamburg, Deutschland, 2.-3. Juni 2022.
Chatelain, Karin; André, Amandine; Freimüller Leischtfeld, Susette; Schneider, Monika; Wick, Sylvia; Keller, Regula; Trachsel, Sonja; Waldner, Tim; Vorburger, Robert; Miescher Schwenninger, Susanne; Chetschik, Irene,
10th Round Table Cocoa, Hamburg, Germany, 2-3 June 2022.
Streule, Stefanie; Freimüller Leischtfeld, Susette; Galler, Martina; Miescher Schwenninger, Susanne,
8(6), pp. e09628.
Available from: https://doi.org/10.1016/j.heliyon.2022.e09628
Ogunremi, Omotade Richard; Freimüller Leischtfeld, Susette; Miescher Schwenninger, Susanne,
International Journal of Food Microbiology.
Available from: https://doi.org/10.1016/j.ijfoodmicro.2022.109563