Content

Syllabus:

1.- Introduction (1)

Food, food and biotechnology. Microbiology, enzymology and transgenic feed.

2.- Applications of microorganisms to the production and modification of foods (1)

Microbiology in the food industry. Historical antecedents. Types of microorganisms of industrial importance. Processes in which they intervene. Industrial activity and traditional elaboration. Importance of environmental determinants.

3.- Microorganisms in foods (1)

Types of microorganisms present in foods. Autochthonous and contaminating microbiota. Types of contaminants. Origin of microorganisms present in foods: environment, raw materials, processing and manipulation.

4.- Microbiological control: preventive measures (1)

Preventive measures. Control of pollution sources. Methods for the evaluation of microbial contamination. Critical levels. Disinfection. Types of disinfectants. Registration of pesticides. Authorized disinfectants in the food industry. Application techniques. Control of the efficiency of the treatment.

 5.- Microbiological control: corrective measures (1)

Treatment of raw materials. Corrective measures. Meaning and purpose of sterilization. Resistance to sterilization. Mechanisms of inactivation. Kinetics of sterilization. Thermal treatments. Chemical sterilization. Irradiation

6.- Limitation of microbial growth (1)

Cold storage: cooling and freezing. Modification of water activity. Use of controlled atmospheres. Modification of the pH. Use of preservatives. System of risk analysis and control of critical points.

7.- Production of cell biomass (1)

Composition and characteristics of the unicellular biomass. Fields of application. Production of cell biomass from carbohydrates. Types of substrates used. Cellular biomass obtained from hydrocarbons. Bacteria that use methane. Growth in methanol. Production from wood, from carbohydrates and from wastewater.

8.- Bread, derivatives and baker's yeast (1)

Historical background. Composition of the raw material. Additives. Microorganisms used in fermentation. Stages in the manufacturing process. Characteristics of the breeding yeast and its production: raw materials. Requirements for growth and fermentation conditions. Fermentation process. Recovery of the product.

9.- Microbiology of the production of alcoholic beverages (1)

 Types of alcoholic fermentation in yeasts and in bacteria. Industrial use. Type of substrate used. Processes used. By-products of fermentation. Efficiency of production. Wine production. Process kinetics. Types of yeast used. Bacteria that participate. Malic-lactic fermentation. Contribution to organoleptic characteristics. Beer production. Type of yeast. Background and surface fermentation. Microbial alterations of the process. Alcoholic fermentation in the process of production of distilled spirits: Type of substrate used and importance of the fermentation by-products in the development of the final characteristics.

10.- Lactic fermentation in plant substrates (1)

Cabbage, cucumber and olives. Microorganisms that intervene. Stages in the maturation of the products. Succession of populations. Microbial alterations of the normal processing process.

11.- Fermentation in meat products (1)

Factors that affect microbial activity in meat products. Cured meats. Physicochemical changes produced by the development of microorganisms. Use of starters.

12.- Lactic acid bacteria in milk-based products (2)

Characteristics of lactic acid bacteria. Starters: properties. Bacteriocines: characteristics and production. Probiotic bacteria: effects, products and applications. Composition of milk. Modification of the raw material. Production of butter. Cutting and serum formation. Fermented milks: type and composition. Microorganisms. Biochemical changes in the fermentation process. Preparation of fermented milks. Cheese: Definition, composition and varieties of cheeses. Microorganisms used. Process for the elaboration of different types of cheeses. Organoleptic characteristics: biochemistry of the production of aromatic compounds.

13.- Production of organic acids and vinegar (2)

Applications of organic acids in food. Production of lactic acid. Production of citric acid. Other acids of interest in food. Historical antecedents of the production of vinegar. Definition, composition and type of vinegar. Acetic acid bacteria. Industrial elaboration of vinegar.

14.- Production of amino acids (2)

Importance of amino acids in food. Enzymatic production processes. Production by fermentation: microorganisms used. Production processes. Recovery of products.

15.- Applications of enzymes for the production and modification of food (2)

Types of enzymes: nomenclature. Activity, kinetics and stability. Control of the action of enzymes. Legislation. Toxicology and safety. Application range. Modification of the activity.

16.- Enzymes in the production of starch derivatives and sugars, bread, pasta, beer and wine (2)

Bread and paste: amylases, xylanases, pentosanases, hemicellulases, lipases, oxidases. Production of starch derivatives. Starch hydrolysis. Maltose and glucose syrups. Fructose syrups. Applications of syrups. Cyclodextrins. Beer: enzymes in malting, cooking, filtration, fermentation and maturation. Wine: Enzymes in the pressing, maceration, clarification, filtration and maturation. Enzymes in the generation of aromas and coloration: manufacture of varieties of white, pink or black wines. Ureases and Lisozim.

17.- Enzymes inthe production of milk-derived foods, food protein modifications, as well as in the production of fruit/plant-based juices and processing of vegetables (2)

Enzymes for coagulation. Proteases and peptidases. Lactoperoxidases. Galactosidases. Transglutaminases. Lipases. Lactases. Origin of the proteases. Applications in the meet and fish industry. Production of protein hydrolysates. Modification of allergens. Modification of the gluten. Pectinases. Cellulases and hemicellulases. Starch and proteins. Applications to the production of juices and plant-derived products: apple, grape, tropical fruits, berries and fruits with kernels. Applications to the processing of citrics, strawberries and tomatoes. Lipases and their industrial applications: hidrolysis and modification of fats/oils.

18.- Functional ingredients and foods. Aromas and additives (2)

Foods with modifications to increase their nutritional properties and health effects (nutraceuticals). New sustainable sources of proteins: development of sustainable food systems. Food addities. Obtaining flavour enhancers with enzymes and microorganisms. .

 

 

Practical sessions and objective of the practicum*

The fermentation of milk is one of the traditional procedures used to modify the characteristics of the raw material, in order to increase its capacity for preservation and improve nutritional and digestive properties.

In our country, the most consumed fermented milk is yogurt. This is obtained by the combined action of two microorganisms in the group of lactic acid bacteria: Lactobacillus bulgaricus (L. delbrueckii ssp bulgaricus) and Streptococcus termophilus.

The growth of the two microorganisms in a situation of proto-cooperation leads to the formation of a series of compounds, of which the most important are lactic and acetic acids, acetaldehyde, diacetyl, acetoin, Acetone. These substances produce a modification of the organoleptic characteristics, while acids cause a decrease in pH to values close to 4. The decrease in pH produces the casein curdling and the formation of an ice with very little loss of Liquid

Thus, the final product is a gel with some rheological and organoleptic characteristics that are dependent on the properties of the raw material and the conditions in which fermentation has taken place (temperature and time of incubation, acid formation velocity, etc.) and subsequent cooling.

The objective of the practice is to deepen in the knowledge of the biological mechanisms of the production of yogurt. In order to study these mechanisms, analytical methods will be used to determine the concentration of the main products of fermentation.

The laboratory practicum will be carried out in the first semester, in 3 sessions of 4 hours each one.