Learning objectives
Physical Chemistry Module:
At the end of the course the student will have assimilated the main themes of Physical Chemistry demonstrating knowledge and understanding of the chemical-physical methods for 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:
- Knowledge and understanding
Students will acquire basic knowledge of the concepts and models of modern physical chemistry. Furthermore, they will learn to analyse the basic molecular transformations and processes which are at the basis of foods properties.
- 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;
- Communication skills by using the specific language of the Physical Chemistry and the correct terminology;
- Making judgements by evaluating with a critical attitude the soundness of the chemico-physical models used in the analysis of the experimental data;
- Learning skills
Applying the acquired knowledge will have to demonstrate that they have developed problem solving skills.
Structure and physical properties of food:
Knowledge and understanding: the course aims to enable the student to acquire knowledge for a in-depth 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 first part of the module is devoted to the equilibrium thermodynamics with special reference to food science.
The second part deals with non-equilibrium thermodynamics and transport processes, particularly those involved in food processing and preservation.
The third part is connected with the colloidal systems and with their stability, particularly as far as the food systems are concerned.
This will complete the scientific knowledge of the students in food science.
Topics:
• Equilibrium thermodynamics applied to chemical, biological and food systems
• Changes of state: physical transformations of pure substances.
• Changes of state: physical transformations of simple mixtures.
• Solutions of macromolecules.
• Equilibria of chemical reactions
• Non-equilibrium thermodynamics and transport processes.
• Colloidal Systems.
Structure and physical properties of food Module:
Introduction
- Amorphous and crystalline states
- Application of phase transition in food products and processes
- Thermal analysis (DSC, TGA and DMA)
- Water status and stability in food
- Microscopy Structure-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.
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.
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. 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. The most common food colloids: Emulsions, foams, dispersions and suspensions, gels.
Structure and physical properties of food Module:
Introduction
- Review of basic concept of rheology
- Viscoelasticy and rheometer
- 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 analysis: DSC, TGA, DMA and application on food products.
- Microstructure characterization: optical and electronic 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.
- Selected scientific papers
- Copy of slides can be downloaded from the Elly website.
Structure and physical properties of food:
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. During oral 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.
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:
The written examination will have to be passed during normal examination sessions.
Questions will have the purpose of establishing the level of knowledge and understanding of the course content, in relation to the educational goals.
If the results of the test will be positive (18/30), the final mark of Structure and Physical Properties of Food examination will be the mean of the mark of the two modules.
During the course, two written in itinere tests will be proposed. The mark of the module will be the mean of the two tests.
Structure and physical properties of food Module:
There are 2 ongoing written tests during the course with open questions (4), whose positive outcome (minimum average grade 18/30 for both tests) leads to passing the exam. The results of the ongoing tests are published on the Elly platform. The final grade is the average of the marks obtained in the two ongoing tests. For students who do not pass at least one of the ongoing tests, the exam consists of a single written test with open questions (8) during the regular exam sessions, carried out at the same time as those of the Physical Chemistry module.
In the case of a positive result, the grade in the module will contribute to the final result for the "Structure and Physical Properties of Food" exam, whose final grade is the average of the marks reported in the two modules.
In case of refusal of the grade of this module, the test (s) previously taken are cancelled, if sustained.
The tests will focus on verifying the level of 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.
Students with SLD / BSE must first contact Le Eli-che: support for students with disabilities, D.S.A., B.E.S. (https://sea.unipr.it/it/servizi/le-eli-che-supporto-studenti-con-disabilita-dsa-bes).
Other information
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