Technology and microbiology of food processing

A.Y. 2019/2020
Overall hours
AGR/15 AGR/16
Learning objectives
The objective is to provide:
- the basic knowledge of the role of microorganisms in food processing
- specific skills for understanding the chemical, physical and biochemical phenomena involved in dairy processing and oenology.
Expected learning outcomes
Learning outcomes are:
- fundamental knowledge regarding dairy and oenological microbiology,
- skills for evaluating and managing some problems related to the processing of milk, grape and related derived products
- capability to identify the most relevant factors to improve the quality of milk and dairy products and wine
- ability to choose and to manage the processing steps that influence the quality of the final products in the mountain areas.
Course syllabus and organization

Single session

Lesson period
First semester
Prerequisites for admission
Animal Biology, Physics, Inorganic Chemistry and Organic Chemistry) and Biochemistry
Assessment methods and Criteria
The examination consists of a written test aimed at ascertaining the student's knowledge of the theoretical and applicative aspects of beer technology and distillates. The written test consists of about 30 closed-ended questions. In order to take advantage of the facilities provided for the exam, DSA students must first notify the Office ( of their situation. Students enrolled in an examination call and who no longer wish to take the exam are required to promptly inform the teacher. In the event of non-compliance, they will not be able to present themselves at the next appeal. The examination method is considered effective for achieving an assessment of skills acquired by the student taking into account the topics covered in the lectures.
Agricultural Microbiology
Course syllabus
Introduction to general and applied microbiology. Structure of prokaryotes and eukaryotes: generality and comparison. Prokaryote morphology and cytology. Growth of microorganisms, methods for its estimation and expression. Influence of environmental factors on microbial growth. Antimicrobial treatments. Microorganisms nutritional requirements. Microbial metabolism and physiological groups. Bacteriophages. Genetics of prokaryotes: mutations and gene recombination. Microbial ecology: interactions among microorganisms and animals. Microorganisms in food conservation and transformation. Dairy microbiology: pro-technologic, alterative and pathogenic micro-organisms. Natural and selected dairy starters. Wine microbiology. Starters for wine production.
Laboratory practices - Sterilization, disinfection, and asepsis. A solid and liquid preparation of culture media. Application of the good aseptic technique to microbiological testing, sowing of bacteria in conditions of sterility and pure culture techniques. Techniques for detection and enumeration of viable microorganisms. Microscopic observation of bacteria: preparation of fresh and colored microscope slides. Microbiological analysis of milk. Microbiological analysis of water. Techniques for the identification of microorganisms.
Teaching methods
The course is designed to provide basic knowledge about morphology, cytology, and physiology of microorganisms. The course focuses on the role of microorganisms in nature and in the biotechnologies for dairy and wine production. The course includes classroom lectures and practical laboratory exercises, useful to acquire basic microbiological techniques.
Teaching Resources
On (Prof. R. Zanchi) a handbook of General Microbiology, with photo-gallery, and material for the laboratory practices, with some videos, are available. Moreover, you can find files with all the slides showed during the lessons and handbooks of Microbial Ecology and Food Microbiology.
Agricultural industries
Course syllabus
MILK - Milk chemistry and microbiology
- Factors affecting milk production and
composition. Physical properties (acid-
base equilibria, density, viscosity,
freezing point). Functionality and
structure of the most important
components of milk (lactose, fat,
caseins, whey proteins, enzymes and
minerals) and their roles in dairy
products. The effects of processing on
the structure and functionality of milk
constituents. Important micro-organisms
in milk and dairy products and factors
affecting their reproduction and survival.
Control of spoilage and pathogenic
micro-organisms during production and
storage of dairy products. Dairy
technology Consumption milk -
Destruction of micro-organisms by heat
treatment: thermisation, pasteurisation
and sterilisation processes. Removal of
micro-organisms by means of
membrane filtration technologies.
Cultured milk - Manufacture technology
of yogurt and cultured milks. Probiotic
properties of lactic acid bacteria.
Cultured milk as functional foods.Butter
- Chemical and microbiological
characteristics of the different types of
cream. Industrial buttermaking
processes. Technologies for production
of anhydrous milk fat. Milk powders -
Technologies for manufacture of milk
powders. Powder agglomeration. Types
and quality characteristics of milk
powder. Cheese - Analysis of the
cheesemaking steps including type of
milk, rennet, cheese starters, processing
within the vat and processing post-vat.
Technologies for manufacture of
different Italian cheeses and processed
cheese. Physical and biochemical
phenomena occurring during
ripening.Quality control of dairy products
including quality standards provided by
either EU specifications or government
regulations. WINE - Composition of
grapes; changes of main grape
components during maturation and the
importance thereof for the fermentation
process and wine quality. Criteria for
determining harvest readiness. Grape
and exogenous enzymes. Glycosidasic
enzymes. Phenolic substances:
anthocyans, flavanols, procyanidines,
tannins. Polimerization and stabilization
of colour. Oxidative pathway in must. The
harvesting and handling of grapes, must
and skins before, during and after
fermentation. Taxonomy and ecology of
grape and wine yeasts. Yeast
oenological characteristics and
condition for yeasts development.
Biochemistry of alcoholic fermentation
and metabolic pathways of wine yeasts.
Microbial spoilage of wines and applied
aspects of moulds and lactic acid
bacteria during winemaking. Malolactic
fermentation. Use of sulphur dioxide in
must and wine treatment. Products and
methods complementing the effect of
sulphur dioxide. Principles of
winemaking including schemes of grape
processing and special demands in
individual technological practices: white,
red, rose and sparkling wines, special
wines and wines of special quality. Fining
agents use optimization. Protein,
tartrate, oxidative, colour and metal
stability Principles and techniques for
physicochemical and microbiological
stabilization of wine. Enzymes in
winemaking. Bottling. Wood barrel
Teaching methods
The course is organized in classroom lectures, using audiovisual methods, for all topics indicated in the course program.
Teaching Resources
Slides of lectures available at
Suggested books:
1.C. ALAIS., Scienza del latte. Tecniche Nuove, Milano, 2000.
2.C. Corradini, Chimica e tecnologia del latte, Tecniche Nuove, Milano, 1995.
3. Ribereau-Gayon P et al.. Trattato di Enologia vol. 1 e 2. Edagricole, Bologna.
Agricultural industries
AGR/15 - FOOD SCIENCE AND TECHNOLOGY - University credits: 6
Lessons: 48 hours
Professor: De Noni Ivano
Agricultural Microbiology
AGR/16 - AGRICULTURAL MICROBIOLOGY - University credits: 5
Laboratories: 16 hours
Lessons: 32 hours
Professor: Zanchi Raffaella
By appointment
Sezione Industrie Agrarie - DiSTAM