Thermophilic Spore‐Forming Bacilli in the Dairy Industry

Cold Microfiltration as an Enabler of Sustainable Dairy Protein Ingredient Innovation

“…and Geobacillus spp. can produce heat-stable proteases and lipases, with important implications for the quality of dairy products; their spore-forming and biofilm-forming abilities also present challenges, as they are difficult to remove and/or inactivate and are also capable of producing acid on growth, reducing pH [ 28 , 36 , 38 ]. Studies have indicated that operating at high temperatures can result in a faster rate of microbial growth and biofilm formation than at low temperatures.…”

“… Schematic representation of some of the microbial considerations when selecting microfiltration processing temperature and the implications of such processing temperatures for processing efficiency and finished product quality. Information regarding examples of bacteria species sourced from [ 36 , 37 , 38 , 39 ]. …”

Development and application of predictive models for the growth of thermophilic spore - forming bacteria in foods

“…Such testing can identify characters that can be used to easily differentiate between species and can reveal properties that are relevant to growth in dairy processing equipment, such as lactose utilization and growth under anaerobic conditions (which is important, as the oxygen content of milk during evaporation is low). Such testing can also reveal the spoilage potential of strains or species, including the ability to produce extracellular enzymes such as amylases, proteases and lipases (Seale et al, 2015). Bianchi et al (2010) have reported the application of the rapid and reliable analytical Gas Chromatography -Mass spectrometry (GC -MS) of volatile compound profile approach for the early detection of Alicyclobacillus acidoterrestris in spoiled orange juice (10 4 CFU/ml).…”

“…Thermophilic bacteria can grow in different manufacturing processes, but the dairy products in which they are a most significant concern are milk powders. Milk powders constitute one of the main dehydrated ingredients of the dairy industry with a prolonged shelf -life, that are used in the manufacturing of UHT -or retort -treated products (Seale et al, 2015). Considering that especially dehydrated ingredients are traded worldwide and originate from regions with different climatic conditions, new endospore -formers that produce highly thermo -resistant spores may emerge and enter the dairy processing environments, thereby challenging the dairy manufacturers (Stoeckel, Lücking, Ehling-Schulz, Atamer, & Hinrichs, 2016).…”

“…However, the development of a biofilm of thermophilic bacilli within a dairy processing plant is still not well understood. Under favorable conditions, biofilms of thermophilic endospore -forming bacilli will develop and both vegetative cells and spores will detach from surfaces, enter the product stream, multiply and contaminate the final product up to a level of 10 6 CFU/ml (Flint et al, 1997;Seale et al, 2015) jeopardizing its quality and safety. Unfortunately, so far, they are difficult to eradicate entirely by cleaning and disinfection, exceeding by far the typical specifications and thus resulting in lower values out -of -specification products (Seale, Flint, McQuillan, & Bremer, 2008) that fail to meet customer requirements.…”