Food Microbiology

Credits: 
12
Year of erogation: 
2020/2021
Unit Coordinator: 
Semester: 
Single Annual Cycle
Year of study: 
2
Language of instruction: 

italian

Modules: 

Learning outcomes of the course unit

The teaching of Food Microbiology aims to put the student in a position to autonomously draw conclusions about the effect of the presence and development of the different microorganisms in foods in accordance with what is defined in the specific objectives of the Degree Course in Science and Technology Food and food microbiology area.
The course aims to introduce the student to the effect of the presence and development of pathogenic, alterative and virtuous microorganisms in food. In particular, the student must be able to understand the different meaning between the concept of microbial contamination and the effect of microbial growth in a food that is both negative in terms of transmission of foodborne illnesses and in terms of alteration of the food, which is positive in terms of food processing by fermentation.
The knowledge of these aspects will provide the student with the essential skills to understand the role of microorganisms in food production with particular reference to the productions obtained by fermentation, and their impact on the quality of food. The use of this knowledge will allow the student to apply the principles of micro-organism control through physical, chemical and biological treatments or combinations to disadvantage or promote development according to their different effect on food and / or consumer.
Considering the size of the total program, it is believed that the learning outcomes are easier to reach by dividing the course into two modules, reserving the "negative" aspects of the microorganisms in the food first, and the "positive" aspects to the second.
At the end of the course, the student must be able to use the scientific language and the specific lexicon of food microbiology appropriately, demonstrating the ability to illustrate and transmit the acquired concepts in oral and written form.

Prerequisites

general microbiology exam is preliminary

Course contents summary

The Food Microbiology course is an integrated course divided into two modules (module 1 - food microbiology and module 2 - and microbiology of fermented foods) designed to facilitate student learning in an annual course
Module 1 is divided into three parts. The first lessons concern general topics related to microbial contamination. The second part of the course is aimed at discussing the effects of the development of pathogenic, alterative and virtuous microorganisms in different foods. The third part of the course deals with the factors that influence the growth of micro-organisms in foods and the modalities of their control in order to prevent or reduce the development of pathogenic and alterative micro-organisms and to favor the development of virtuous micro-organisms.
Module 2 is divided into three parts. The first lessons concern general topics related to fermentation, spontaneous or guided, as a method of preserving and processing food. The second part of the course concerns the knowledge of the main microbial protagonists of fermentations: lactic bacteria and yeasts and their use as natural or selected starters. The third part of the course deals with the characteristics and the microbial dynamics at the base of the production of the main fermented foods of animal and vegetable origin.

Course contents

1 Module. Microbiology and foods: basic concept of microbial contamination and microbial development in food. Food microbial quality: Microorganisms as indicators of process and contamination. Microbial contamination and food. Microbial growth phases and factors conditioning their development in foods: i) intrinsic (water activity, pH, Red-ox, nutrient, antimicrobial compounds), ii) extrinsic (temperature, humidity, atmosphere packaging, preservatives, treatments) and implicit (microbial interaction). Spoilage of microbial origin: spoilage microorganisms and different type of food spoilage. Food borne microorganisms. Microbial food safety risk assessment of most important foodborne pathogens. Control of microorganisms in food. Safety, sterility and stability. Effect of some food control strategies: thermal treatment, water activity reduction, pH decrease, others. Main microbial aspects of: water and non alcoholic beverage, milk, meat, fish, fruit and vegetable, eggs, honey, preserved food
2 Module. Fermentation as a method of food processing. Spontaneous and driven fermentation. 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. Role of microorganism involved in vinegar and balsamic vinegar production. Microbiological role in bear production. Microbiological role in meat fermentation. The microbiological role in bread production, yeast and lactic acid bacteria. Other vegetal fermented food: role of microorganisms in soia products, olives, sauerkrauts. Extractive fermentation: cacao

Recommended readings

Giovanni Antonio Farris, Marco Gobbetti, Erasmo Neviani, Massimo Vincenzini “Microbiologia dei prodotti alimentari” (2012) Casa Editrice Ambrosiana ISBN: 978-88-08-18246-
slides of lessons available on Elly

Teaching methods

The teaching will be carried out through frontal lessons with the help of slides that will represent educational material, supplementing the recommended text, made available on Elly in pdf format for students. The lessons include the discussion of examples of real cases
The course includes practical and theoretical experience on the principles and methods of analysis that underlie research and the direct and indirect counting of microorganisms in food.
The content of the exercises lessons will be an integral part of the final evaluation.

Assessment methods and criteria

At the end of each module the learning level of the expected results will be verified for all the contents offered during the lessons, including the lessons of exercises. The learning check of the first module will be carried out through a single partial test, while the second module will be tested by means of a minute record requesting the registration of the final grade as the average of the two results (if at least above 18/30).
The result of the vote obtained in the second module will be indicated on Esse3 in the "notes for the student"
Both the partial proof and the minutes recording are carried out by means of a written exam. The written exam, to be carried out within 1 hour and 30 minutes, consists of three parts
1. The first part consists of 10 questions that verify the knowledge of the fundamental concepts of the course. For this reason only if the answer to all the questions is correct, the following parts will be evaluated
2. The second part consists of 21 questions to assess the level of knowledge acquired in all the topics covered. Each correct answer is worth 1,5 points. The achievement of the sufficiency threshold of this second part is binding for the correction of the third part. The sufficiency of 18/30 is achieved with at least 12 correct answers. The vote achieved will weigh 70% on the voting of the first module
3. The third part consists of an open-ended question in which the student must demonstrate that he is able to correctly express the acquired competence with the specific scientific language of food microbiology. The answer will be evaluated in 30ths. The rating achieved in this part will weigh 30% on the voting of the second module.

Other informations

Lessons frequency for the first and the second module is strongly encouraged.