Learning objectives
The course will provide the essential elements for understanding the role of microorganisms in food production and their impact on food quality. In particular the objectives are the following:
a) Knowledge of the role of pathogenic microorganisms, both useful and harmful in foods
b) Knowledge of the main illnesses transmitted through food
c) Knowledge of the alterations of microbiological origin in foods
d) Knowledge of the intrinsic, extrinsic and implicit factors which influence the development and survival of microorganisms in food
e) Understanding the principles of the control of microorganisms through physical, chemical and biological treatments, or their combinations
f) Knowledge of biological aspect regarding industrial application of microorganisms.
g) Comprehension of principles which link the different technology processes to the use of microorganism for producing fermented food
Prerequisites
the course aims to familiarize the student with the main aspects of microbiology and foods, so the prerequisites are a knowledge of microbiology in general.
Course unit content
The microbiological quality of foods. The microorganisms in fermented and non fermented foods. Microorganisms in foods: bacteria, yeasts and moulds. Microorganisms as indicators of process and contamination. Pro-technological microorganisms, modifiers, pathogens. Modifying microorganisms: food degradation. Pathogenic microorganisms: pathogenesis. Infections and food poisonings: definition. Virulent and toxic factors. Pathogenic microorganisms in foods: Gram – and Gram +. The contamination of foods. Factors which influence the growth of microorganisms in foods: temperature, pH, Aw, potential redox and availability of oxygen, food composition. The control of growth and survival: checking pH. Checking the Aw, use of low and high temperatures, packaging and protective atmospheres. Other technological interventions that impact microorganisms: treatment with ionized radiation. Applications of high pressure and electric pulses. Food additives
Presence of microorganisms in fermented food: Lactic acid bacteria, yeast, natural and selected starter. Microorganisms in dairy products: fermented milk, yogurt and cheeses.
The microbiological role in wine production. Yeast, lactic acid bacteria and mould in red win, white wine and special wine. The microbiological role in bear production. The microbiological role in meat fermentation. The micorbiological role in bread production, yeast and lactic acid bacteria. The microorganism involved in vinegar and balsamic vinegar production. Other vegetal fermented food: role of micorganism in soia products, olives, sauerkrauts, coffe and cacao
Full programme
Food processing: from raw material to ready-to-consumer food
Microbiological aspect determining the processing of raw materials in fermented foods
Presence of microorganisms in fermented foods: lactic acid bacteria, probiotic bacteria, yeasts, natural and selected starters
Microbial aspects in dairy products: microorganisms of yogurt and fermented milk, cheese: significance of the microorganism at various stages of production, microorganisms characteristic of some types of cheese
The role of microorganisms for the production of fermented meat products (salami): Factors conditioning Micrococcacee of microbial growth, lactic acid bacteria and mold; The natural fermentation and ripening
The role of microorganisms for bread production. Fermentation and substrate fermentation. Yeast; Microbial ecology of sourdoughs
The role of microorganisms in the winemaking process: The wine yeasts and alcoholic fermentation. Lactic acid bacteria: the defects and the malolactic fermentation. Role of microorganisms in the production of special wines (vini novelli, sweet wines, sparkling wine or champagne, fortified wines)
The role of microorganisms in beer production: the possible microbial contamination and hygiene problems in the early stages of malting and mashing, fermentation and starter cultures
The role of microorganisms in the production of vinegar: acetic acid bacteria in wine and vinegar, acetic acid bacteria and yeasts balsamic vinegar
Bibliography
Giovanni Antonio Farris, Marco Gobbetti, Erasmo Neviani, Massimo Vincenzini “Microbiologia dei prodotti alimentari” (2012) Casa Editrice Ambrosiana ISBN: 978-88-08-18246-
Teaching methods
Frontal lessons and practical execrcises
Assessment methods and criteria
written examination
Other information
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