With the increase in the consumption of dairy desserts and the need for a better control of food wastes, food spoilage has become of main concern for the dairy industry. It then appears essential to better understand and control this issue, which have been poorly investigated so far. Amongst the dairy desserts, we have focused our research on the famous French dessert “île flottante”, particularly sensitive to spoilage. This food consists of a sweet egg white foam floating on a vanilla custard cream, which contains highly nutritive raw materials, including milk, sugar and egg. We have shown that the bacterial spoilers are mainly Gram-positive bacteria belonging to the Bacillus cereus group, and the Staphylococcus and Enterococcus genera. Further experiments were designed for better understanding of the bacterial metabolic activities involved in custard cream spoilage events. Lactic acid appeared as a relevant marker for an “objective” detection of spoilage and the volatilome as a fingerprint for the assignment of a type of spoilage to a specific bacterium. These markers could be of interest for the development of new diagnostic tools for the dairy or egg product industry where objective criteria are lacking for the detection and control of spoilage issues.
Dr. Clarisse Techer is born in 1983. She obtains a Msc degree in Microbiology at the Rennes 1 University (Fr) in 2009. In 2010, she works on the establishment of sensitive and specific immunological methods for the detection of staphylococcal enterotoxins in dairy products. In 2012, she joins the Animal nutrition and processing domain of the Avril group (Fr) and undertakes a PhD research in the joint research unit “Science and Technology of Milk and Egg” between Agrocampus Ouest and the French National Institute for Agricultural Research (INRA). Her PhD work concerned the control of spoiling bacteria in refrigerated food composed of egg products. Since 2015, she works in the Department of Research, Innovation and Development (RID) of Mixscience (Avril group) in Rennes (Fr) as researcher in microbiology and then as RID manager. Her main current research interests include animal gut health management, search for alternative solutions to the use of antibiotics in animal feed, mycotoxin risk management and quality of finished products such as egg products. She is also supervising MSc and PhD students.