Subject: TECHNIQUES FOR SHELF LIFE PREDICTION (A.A. 2023/2024)
Food Technologies (lesson)
Aim of the course is to give basic knowledge about foreseeing of packaged food products shelf-life, by means of the application of simulated, accelerated shelf-life tests and the use of predictive mathematical models.
Knowledge of biochemistry, analytical chemistry, food process and food packaging technologies, as well as of the packaging materials properties.
The credits for each activity of the program, which may vary according to the learning time of the students, will be structured as followsCFU 0.25 (2 hours)
Introduction. Definition of shelf-life and contextualization of the topic in food technologies
CFU 0,75 (6 hours)
Definition of primary degradation events and disanimation of their effects on food quality; definition of the influence of the environment on food degradation: pressure, gas and water vapor, light, temperature. Definition of a procedure for the study of the shelf life of foods.
CFU 0.75 (6 hours)
Kinetics of reactions and models for predicting qualitative decay; influence of temperature: Arrhenius equanzion; activation energy of reactions; definition of Q10; numerical exercises on the application of models and use of spreadsheetsCFU 0.50 (4 hours)
Strategy for the study of shelf life. Product shelf life and dependent packaging. Simulated, accelerated shelf life and modeling of shelf life.
CFU 1.0 (8 hours)
Shelf life dependent product: effect of temperature and temperature fluctuations; numerical exercises
CFU 0.5 (4 hours)
The water and food relationship. Definition of water activity and influence on food stability. Construction of adsorption isotherm
CFU 1.25 (10 hours)
shelf life packaging dependent. Definition of models with constant driving force for oxygen and water vapor; numerical exercises. Definition of variable force models: the use of the linearized isotherm for water vapor; the general model for oxygen exchanges.Light transmission and shelf-life.
Teaching methods Lectures: minimum 38 hours (19 * 2 hours) Pratical (calculation exercises): maximum 10 hours (5* 2 hours) Attendance at lessons is not compulsory, but strongly recommended
Oral examination (30/45 minutes) Students must be able to discuss the main approaches in the food shelf-life studies. Students must able to design experiments to state or verify the food shelf-life. The exams take place over the course of the academic calendar and for each session students must register using the ESSE3 platform. There are no intermediate evaluations.
Learning Outcomes: On successful completion of this module, students should be able to:
- Use composition of foods to predict their physicochemical properties and changes in processing and storage.
· Explain factors controlling rates of chemical, enzymatic and physical changes in foods.
· Select appropriate test methods to verify the shelf life "product" or "packaging" dependent
· Apply mathematical to predict reaction rates in foods.
- Apply models to predict the shelf-life "packaging dependent"
The students will be able to discuss and present the result of computational prediction of food shelf-life.
The discussion during lectures and practicals will give to the students the ability to communicate to specialist audiences. This ability will be verify during the oral final examination.
The studentds, as a consequence of the described activities, will be able to find relevant information from the specific scientific literature for a self-directed and largely autonomous study.
Testi di riferimento:
Materiale didattico distribuito durante il corso
Testi consigliati per approfondimenti:
G.L. Robertson, Food packaging: principles and pratice, CRC Press