Learning objectives
Physical Chemistry Module:
At the end of the class, the students would acquire the ability of applying the acquired knowledge and understanding to the study of the structure and physical properties of foods and to the main production and preservation processes.
At the end of the class, the student must be able to show:
1. knowledge and understanding by:
- using the specific language of the Physical Chemistry and the correct terminology;
- showing knowledge and understanding of the principles, foundations of the Physical Chemistry, notably about classical thermodynamics, applied to the chemical reactions, to the foods and to the biological systems for understanding the main machinery related to food preservation and production and the basics of the main techniques for studying the structure and physical properties of foods, transport processes, explained by means of non-equilibrium thermodynamics models, and their importance in food processes, stability of the colloidal systems and their involvement in the food field;
2. applying knowledge and understanding by:
- applying the knowledge to the study of chemical processes in food area by means of chemico-physical techniques, in order to verify their feasibility and optimization;
- dealing with the experimental data by means of models;
3. communication skills by:
- communicating the results of scientific studies also to a non-expert audience;
- writing a formal document, understandable and appropriate for the professional context;
- transferring his intuitions and analysis to the working group by using the specific language of the Physical Chemistry and the correct terminology;
4. making judgements by:
- evaluating with a critical attitude the soundness of the chemico-physical models used in the analysis of the experimental data;
5. learning skills by:
- studying in a self-governing way;
- updating his knowledge by reading basic and advanced books and consulting the scientific publications in the field;
- connecting the different subject treated in the class with the disciplines studied in the year after.
Structure and physical properties of food Module:
Knowledge and understanding: the course aims to enable the student to acquire knowledge for a deepen understanding of factors influencing macroscopic properties, stability and microstructure of food products and analytical techniques for the physical characterization of food matrices.
Applying knowledge and understanding: the course aims to make the student able to apply the acquired concepts in food industry for the evaluation and control of physico-chemical stability and structure of foods.
Making judgments: based on the information acquired, the course intends to provide students with the tools useful to critically discuss food structure in relation to their stability, and the choice of proper analytical techniques to study such factors.
Communication skills: the course intends to provide the student with a proper technical-scientific language useful for the communication to the sector experts and not experts.
Learning skills: the course aims to provide the student with the learning skills necessary to study in a widely autonomous way, by searching for case studies that are discussed in class.
Prerequisites
Physical Chemistry Module:
No preliminary examinations are requested
Structure and physical properties of food Module:
Unit operations of food technologies and food processes.
Course unit content
Physical Chemistry Module:
The aim of the module is knowledge and understanding of the principles underlying physical processes and chemical reactions, by means of models, peculiarity of the Physical Chemistry. The first part of the module is devoted to the equilibrium thermodynamics with special reference to food science (water activity, food phase diagrams, etc.).
The second part deals with non-equilibrium thermodynamics and transport processes, particularly those involved in food processing and preservation ( viscosity, diffusion, sedimentation).
The third part is connected with the colloidal systems and with their stability, particularly as far as the food systems are concerned.
Structure and physical properties of food Module:
- Crystalline and amorphous state, phases, first and second order phase transitions, phase transition in food, phase transitions in food products and processes.
- Water state in different structural levels and food stability
- Thermal analytical techniques: DSC, TGA, DMA.
- Rheological techniques: texture and rheometric analysis
- Microstructure characterization: microscopy
- Structure-nutritional, technological and sensorial functionality relationship.
Full programme
Physical Chemistry Module:
1. Equilibrium thermodynamics applied to chemical, biological and food systems with a statistical thermodynamics outline. Variables and state functions. The laws of thermodynamics. The temperature and pressure dependence of thermodynamic quantities. Thermochemistry. Calorimetry. Outline of statistical Thermodynamics. Exercises.
2. Changes of state: physical transformations of pure substances. Phase diagrams. Clapeyron and Clausius-Clapeyron equations. Gibbs phase rule
3. Changes of state: physical transformations of simple mixtures. Open systems and partial molar quantities. Ideal and real solutions. Raoult and Henry laws. Fugacity and activity. The water activity in foods and food preservation. Regular solutions. Ideal mixing and excess functions. Phase equilibria in binary systems. Fractional distillation. Azeotropes, eutectic, partially miscible liquids, binary mixtures compounds forming. Phase transition in food materials. The glassy state and the glass transition.
4. Solutions of macromolecules. Solvent chemical potential. Colligative properties. Osmotic pressure. Molecular weight measurements. Membrane equilibria. Dialysis equilibrium. Donnan equilibrium.
5. Equilibria of chemical reactions. Thermodynamics of chemical equilibrium. Gibbs free energy and equilibrium constant. Activity and ionic strength. Exergonic and endergonic reactions. Coupled reactions.
6. Non-equilibrium thermodynamics and transport processes. Order out of caos. Force and flow. Phenomenological equations. Theorems. Onsager law. Dissipation function. Steady state concept. Mobility of the ions in solution. Electrophoresis. Diffusion. Sedimentation. Viscosity.
7. Colloidal Systems. Dispersed systems. Size and shape of colloidal particles. Ostwald classification. Surface tension and surface free energy. Van de Waals forces. Lennard-Jones potential. Intermolecular forces in colloidal systems. DLVO theory. Hydrophobic interactions, hydrophobic hydration and Hydrophobic effect : model for the interpretation. Structure and classification of surfactants. Micelle formation. Casein Micelles. Emulsifiers and stabilizers in foods. Cohesion and adhesion work, spreading coefficient, wettability. Ostwald ripening. Gibbs isotherm. Laplace pressure. The most common food colloids: Emulsions, foams, dispersions and suspensions, gels. Methods of preparation. Examples: beer, whipped cream, ice-cream, meringue, butter, mayonnaise. Natural emulsions: milk, eggs, oleosomes, and stabilization methods used by the nature. Marangoni effect. Physico-chemical properties of a food colloid. Micro-emulsions. Lyotropic and thermotropic liquid crystals.
Structure and physical properties of food Module:
- Crystalline and amorphous state, phases, first and second order phase transitions, phase transition in food, phase transitions in food products and processes.
- Water state in different structural levels and food stability
- Thermal analytical techniques: DSC, TGA, DMA.
- Rheological techniques: texture and rheometric analysis
- Microstructure characterization: microscopy
- Structure-nutritional, technological and sensorial functionality relationship.
Bibliography
Physical Chemistry Module:
- J. N. Coupland, An Introduction to the Physical Chemistry of Food, Springer, New York (2014)
- P. Walstra, Physical Chemistry of Foods, Marcel Dekker, Inc, New York (2003)
- P. W. Atkins, J. De Paula, Elementi di Chimica Fisica, quarta edizione italiana, Zanichelli, Bologna, 2018.
- P. Atkins, J. De Paula, Chimica Fisica Biologica 1 e 2, Zanichelli editore, Bologna (2008).
- E. Dickinson, M. Leser, Food Colloids - Self-Assembly and Material Science, RCS Publishing, 2006.
Structure and physical properties of food Module:
Mandatory:
- .pptx presentations used during the lessons.
- Chapters 4,5 and 13 of the text “Food Materials Science: Principles and Practice (Food Engineering Series), Aguilera, Lillford, 2008, Springer”
To deepen the study:
- Food texture and viscosity, concept and measurement, 2nd edition, Bourne, Academic Press, Food Science and Technology, International Series
- Non-Equilibrium States and Glass Transitions in Foods, 1st Edition, Processing Effects and Product-Specific Implications, Eds. Bhesh Bhandari Yrjö Roos.
- Phase Transitions In Foods, Roos, 1995, Academic Press
- Physical properties of foods: novel measurement techniques and applications Arana, 2012, CRC Press.
Teaching methods
Physical Chemistry Module:
Lectures are carried out face to face. Some lectures recorded in advance are also made available to the students through the Elly platform of the course. If the pandemic situation is still lasting, distance learning by live streamed lectures, via Teams platform, will be active, too. During lectures, done by means of computer ppt presentations, available to the students before classes in the web site (ELLY) of the class, general topics related to the use of chemico-physical models for studying food and biological systems will be discussed. Lectures will be implemented by means of problem solving and “question time” like activities in order to maximize the understanding level of the students. ELLY slides, as well the associated videos, are integral part of the teaching material.
Structure and physical properties of food Module:
The lessons will be organized face-to-face. During the lessons, face-to-face situations will be alternated with interactive situations.
Seminars and the individual reading and class discussion of scientific articles will be offered.
Assessment methods and criteria
Physical Chemistry Module:
If it is possible face to face teaching, to verify the achievement of the expected expertises, during teaching activity the students can take two written “in itinere” tests with open questions. One hour is available for each test. The exam is passed if the average mark is equal or greater than 18/30 and no mark of the “in itinere” tests is under 16/30. The results of the “in itinere” tests are published on Elly platform. For the students unable to pass at least one “in itinere” test, there is a written examination during scheduled examination sections (seven open questions in two hours). Otherwise, if distance examination through Teams platform must be performed, there is only an oral examination on the whole syllabus during scheduled examination sections (without “in itinere” tests).The obtained marks will contribute to the final result for the exam of the class of “Structure and Physical Properties of Food”, being the final mark the average between the marks obtained in the two modules constituting the class.
In case of pandemic restriction, “in itinere” tests will be administered at distance on the ELLY platform with the same procedures above described.
Structure and physical properties of food Module:
Written exam with open questions that will verify the acquired knowledge by the student and the ability to apply such knowledge to the solution of case studies. Moreover, it will be also evaluated the technical-scientific language acquired.
The exam is made by 4 open questions where a maximum of 8 points can be given for each question.
Other information
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