Quantitative Characterization of Geotrichum candidum Growth in Milk

Abstract

The study of microbial growth in relation to food environments provides essential knowledge for food quality control. With respect to its significance in the dairy industry, the growth of Geotrichum candidum isolate J in milk without and with 1% NaCl was investigated under isothermal conditions ranging from 6 to 37 °C. The mechanistic model by Baranyi and Roberts was used to fit the fungal counts over time and to estimate the growth parameters of the isolate. The effect of temperature on the growth of G. candidum in milk was modelled with the cardinal models, and the cardinal temperatures were calculated as Tmin = −3.8–0.0 °C, Topt = 28.0–34.6 °C, and Tmax = 35.2–37.2 °C. The growth of G. candidum J was slightly faster in milk with 1% NaCl and in temperature regions under 21 °C. However, in a temperature range that was close to the optimum, its growth was slightly inhibited by the lowered water activity level. The present study provides useful cultivation data for understanding the behaviour of G. candidum in milk and can serve as an effective tool for assessing the risk of fungal spoilage, predicting the shelf life of dairy products, or assessing the optimal conditions for its growth in relation to the operational parameters in dairy practices.

A novel approach for accelerating smear development on bacterial smear-ripened cheeses reduces ripening time and inhibits the growth of Listeria and other unwanted microorganisms on the rind

“…On smear ripened cheeses, these yeasts have been reported to provide growth factors for the smear bacteria (Beresford et al, 2001;Cogan, 2016). However, uncontrolled yeast growth is not beneficial as this can lead to off-flavors, slick rinds, and toad skin deformities (Westall & Filtenborg, 1998;Šipošová, Koňuchová, Valík, Trebichavská, & Medved'ová, 2021). Here, we have demonstrated that the anti-yeast effect of B. linens CX3, at least partially, can be attributed to its ammonia production.…”

Microbial Dynamics of a Specialty Italian Raw Ewe’s Milk Cheese Curdled with Extracts from Spontaneous and Cultivated Onopordum tauricum Willd

“…The occurrence of Acinetobacter johnsonii , Staphylococcus spp., and Candida parapsilosis has previously been documented in raw milk of the same sheep breed [ 34 , 35 ]. Geotrichum species, mainly G. candidum , are also commonly associated with milk and cheese [ 57 , 58 , 59 ]; although recognized as synonym of Galactomyces candidus [ 60 ] due to phylogenetic affinity, to the best of the authors’ knowledge this is the first study reporting the identification of Geotrichum silvicola in raw ewe’s milk and cheese. Great interest is addressed to the yeast Yarrowia lipolytica for its proteolytic and lipolytic activities, and the consequent aroma development during cheese ripening [ 61 , 62 , 63 ].…”

Uncovering the Biotechnological Importance of Geotrichum candidum

“…The deamination reactions performed by G. candidum , which lead to the production of aldehydes, ammonia, and organic acids, influence the cheese’s sensorial characteristics [ 3 , 37 , 38 ]. In general, G. candidum -associated sensorial characteristics include mildly cheesy, sweaty, moldy, yeasty, fermented, acidic, putrid, cidery, musty, and fruity flavors, and lightly velvety or fluffy appearance [ 3 , 39 ].…”