FFoQSI: Propionic acid bacteria and cheese spoilage
Abstract
During milking, milk is colonized by bacteria from a variety of sources in the stable environment, such as the teat skin, milking equipment and personnel, air, water, feed, and bedding material. Some of these bacteria may cause severe spoilage in dairy products and lead to financial losses for the dairy industry. Propionic acid bacteria are among these bacterial contaminants, which are particularly affecting hard cheese quality. However, their role during cheese production and ripening is ambiguous. Propionibacterium freudenreichii may be deliberately added to vat milk to create the typical eyes and nutty flavor of Emmental cheese. In other raw milk cheeses, however, the presence of propionic acid bacteria and their fermentation products may lead to major quality defects, such as brown spots or blowing defects. A decisive step to avoid cheese spoilage in these cheeses is the use of high-quality raw milk. Hence, knowledge about contamination levels of propionic acid bacteria in raw milk is crucial for an accurate quality assessment. However, conventional microbiological methods to enumerate propionic acid bacteria are time-consuming, labor-intensive and lack selectivity. Faster and more specific molecular methods are available, but high costs and the demand for equipment and specialized personnel have prevented the implementation of these methods for routine monitoring purposes in the dairy industry. The aim of this project is to develop and optimize a microbiological method for the enumeration of propionic acid bacteria that will facilitate routine monitoring of these contaminants in raw milk and avoid quality defects during cheese production.
keywords cheese spoilage milk method development propionic acid bacteria
Publikationen
Bakterien in der Rohmilch: eine Zerreißprobe für Hartkäse
Autoren: Burtscher, J; Domig K J Jahr: 2021
Journal articles
Propionic acid bacteria in the food industry: An update on essential traits and detection methods.
Autoren: Bücher, C; Burtscher, J; Domig, KJ; Jahr: 2021
Journal articles
Project staff
Konrad Domig
Univ.Prof. Dipl.-Ing. Dr.nat.techn. Konrad Domig
konrad.domig@boku.ac.at
Tel: +43 1 47654-75453
Project Leader
01.01.2021 - 31.12.2024
Johanna Burtscher
Ass.Prof. Dipl.-Ing. Dr. Johanna Burtscher Bakk.techn.
johanna.burtscher@boku.ac.at
Tel: +43 1 47654-75456
Sub Projectleader
01.01.2021 - 31.12.2024
Larissa Bischof
Dipl.-Ing. Larissa Bischof
larissa.bischof@boku.ac.at
Tel: +43 1 47654-75473
Project Staff
01.01.2023 - 31.12.2024
Carola Bücher
DI.in Carola Bücher
carola.buecher@boku.ac.at
Tel: +43 1 47654-75468
Project Staff
01.01.2021 - 31.12.2024
Tamara Rudavsky
DI.in Tamara Rudavsky
tamara.rudavsky@boku.ac.at
Project Staff
01.01.2021 - 31.12.2024
BOKU partners
External partners
Gebrüder Woerle limited
none
partner
Agrarmarkt Austria Marketing GmbH
none
partner
SY-LAB' Geräte, Zubehör und Systeme für Laboratorien Gesellschaft m.b.H.
none
partner
Obersteirische Molkerei eGen
none
partner
Qualitätslabor Österreich eGen
none
partner
Dorfsennerei Schlins-Röns und Umgebung eGen
none
partner
Kärntnermilch reg.Gen.m.b.H.
none
partner