Chapters authored
Staphylococcus aureus: Characterisation and Quantitative Growth Description in Milk and Artisanal Raw Milk Cheese Production
Part of the book: Structure and Function of Food Engineering
Lactic Acid Bacteria and Fermentation of Cereals and Pseudocereals
The usage of lactic acid bacteria (LAB) in food as starters in fermentation technologies has a long tradition. Although the theorized idea of host‐friendly bacteria found in yoghurt has been formulated only over a century ago, both groups are widely used nowadays. Lactic acid bacteria alone or with special adjunct probiotic strains are inevitable for the preparation of various specific fermented and probiotic foods. Moreover, because of their growth and metabolism, the final products are preserved for a certain time. Growth dynamics of probiotic LAB and Fresco DVS 1010 in milk‐ and water‐based maize mashes with sucrose or flavours (chocolate, caramel and vanilla) were evaluated in this study. Although milk is typical growth medium for the LAB growth, observed strains showed sufficient growth in each of prepared mashes as well as they were able to maintain their content above 106 CFU ml-1 during storage period (6°C/21 d). Designed flavoured mashes were acceptable from the microbiological point of view, but according to the sensory evaluation they were provided with an attractive overall acceptability and are adequate alternative for celiac patients, people suffering from milk protein allergies or lactose intolerance.
Part of the book: Fermentation Processes
Staphylococcus aureus Enterotoxin Production in Relation to Environmental Factors
Staphylococcal enterotoxins (SEs) and SE-like toxins (SEls) are the most notable virulence factors associated with Staphylococcus aureus. They are involved in food poisoning, toxic shock syndrome and staphylococcal infectious diseases in human. In dairy practise, the initial numbers of S. aureus play an important role especially at the beginning of the milk fermentation within the first 6 h or in 24-h-old cheese. As we presented in our previous works, one of the most effective tools to inhibit S. aureus growth is by adding a sufficient amount of active dairy starters, which are able to produce lactic acid very rapidly. Thus, by inhibiting the growth of S. aureus the production of SEs may be reached. Based on this study focusing on the effect of temperature, pH, water activity and initial numbers of lactic acid bacteria on the growth and the ability of S. aureus 14733 to produce SED, we consider it as a strong SED producer. The SED production was not limited with the incubation temperatures and the NaCl addition related to traditional cheese manufacture. As this isolate comes originally from such an artisanal cheese production, we can expect that other strong SE producer could be present in milk or environment. Besides strict prerequisites approach in production hygiene, it is necessary to add the starters ensuring the initial dominance of lactic acid bacteria (LAB) and supporting the growth of the natural LAB present in raw milk.
Part of the book: The Rise of Virulence and Antibiotic Resistance in Staphylococcus aureus