Shelf-life calculation and estimation - Prof. Giampiero Sacchetti - a.a. 2023/2024
Food science and technology - 2nd year
Indice degli argomenti
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Associate Professor in Food Science and Technology (AGR / 15) at the Department (former Faculty) of Biosciences and Technologies for Food, Agriculture and Environment of the University of Teramo since 2015. Degree in Agricultural Sciences, Postgraduate Diploma in Food Chemistry and Technology and PhD in Food Science at the University of Bologna. "Visiting scientist" at the Department of Food Science and Nutrition of the University of Minnesota (USA) in 2002 (Supervisor: Prof. T.P. Labuza). University Researcher and University Researcher Confirmed in Food Science and Technology at the Faculty of Biosciences and Technologies for Food, Agriculture, and Environment (formerly Agriculture) of the University of Teramo from 2002 to 2015. Member of the Board of Professors of the PhD in Food Science of the University of Teramo since 2003. President of the International Master's Degree Course in "Food Science and Technology" of the University of Teramo from 2018 to today.
Research activity:
- Chemical, physical and sensory analysis of food;
- Statistical analysis applied to food sciences;
- Innovation, development and optimization of food industry processes;
- Antioxidant activity of biomolecules and oxidative stability of food;
- Shelf-life of food;
- Role and status of water in food;
- Technology of cereals and derivatives.
Coordinator and scientific manager of the operational unit of 6 research projects evaluated through 'peer review'.
Author or co-author of more than 230 research products including papers, conference proceedings and posters from whose citations an h-index of 41 has been calculated (source: Google Scholar) which makes him count in the list of Top Italian Scientists (topitalianscientists.org). The 104 papers also reviewed on the Scopus database have collected 3500 citations, allowing the author to reach an h-index of 37 (source: Scopus).
Qualified for the role of Full Professor since 2016 thanks to his scientific activity (attested by bibliometric indexes) and the scientific responsibility of the projects he was responsible for.
PREREQUISITES AND PROPEDEUTICITY
- Prerequisites:
The following exams are recommended:
Food Technology I .
- Propedeuticity: None
TARGETED LEARNING OUTCOMES
Knowledge and understanding:
The student will be able to:
• define the basic principles at the basis of shelf-life calculation;
• describe the factors affecting shelf-life and their possible interactions;
• explain the different approaches which are used to study the shelf-life of foods;
• describe the methodologies used to perform shelf-life calculations.Applying knowledge and understanding:
Students will have to:
• integrate previous knowledge of food chemistry, food technology, and food microbiology in order to perform a shelf-life evaluation (team work project);
• carry out a shelf-life test by using analytical data collected on literature or in laboratory experience and calculate the results (team work project);Making judgements:
Students should be spurred to:
• demonstrate judgement skill in discussing the advantages and limitations of shelf-life testing;
• demonstrate judgement skill in discussing their own results of shelf-life calculations in comparison with literature data;Communication skills:
Students will have to:
• Make a shelf-life calculation report (team work project)
• Make a computer aided presentation of their team work project projectLearning skills:
Students will be supplied with new tools to learn:
• how to calculate shelf-life solving n-order and mixed order kinetic models. The tool Solver which could be found in Excel (Open access, Windows or Mac) sheets is used to this purpose and, possibly, a specific add-in given by the teacher will be supplied to students.TEACHING UNITS
Unit 1. Shelf-life definition. Quality loss and choice of quality indices. The main chemical and biochemical responsible for food spoilage and quality decay. Intrinsic and extrinsic factors affecting the rate of food quality decay. The role of temperature and mobility.
Unit 2. Shelf-life calculation: product-dependent approach. The kinetics of food quality decay (zero, first, second a n-order). Effect of temperature on reactions rate: the Arrhenius equations. Linearization and modifications of the Arrhenius equation: advantages and disadvantages.
Shelf-life tests and accelerated shelf-life tests (ASLT) in isothermal conditions. Examples of calculations.
Unit 3. Shelf-life tests and accelerated shelf-life tests (ASLT) in non-isothermal conditions. The calculation for discreet-time intervals. The calculation of the most probable exposure temperature. The use of time temperature indicators (TTI). Validation of a TTI.
Unit 4. Degradative phenomena following mixed order kinetics. Enzymatic reactions, diffusion kinetics, microbial growth kinetics. Probabilistic quality loss equations. Phase transitions, texture changes and the use of probabilistic quality loss equations.
Unit 5. Reactions kinetics in concentrated food systems: the polymeric approach to food stability. Phase transition and state changes in food. Phase transition and the WLF equation.
Phase transition and WLF-like quality loss kinetics. Phase transitions, texture changes and the use of probabilistic equations for quality loss modelling. Integration of Arrhenius dependent approach and polymeric approach to calculate the shelf-life. Study cases on modified Arrhenius equations.
Unit 6. Role of packaging in shelf-life extension. Water and oxygen transmission rate of packaging materials. Calculation of shelf-life using a packaging dependent approach.
Class exercises
1. Use of the Solver and Solver aid for xls. Determination of the order of a quality loss kinetic.
2. Shelf life calculation using an n-order kinetic. Calculation of an Arrhenius plot (linearized and non-linearized) and time-temperature modified Arrhenius plot.
3. Shelf-life calculation using a pseudo-diffusion kinetic. Calculation of a time-temperature modified Arrhenius.
4. Shelf-life calculation using a probabilistic approach. Calculation of a time-temperature modified Arrhenius plot. Comparison of results with those obtained in exercise 3.
5. Shelf-life calculation using the Gompertz equation. Calculation of a time-temperature modified Arrhenius plot.
6. Shelf-life calculation of a frozen food. Application of a modified Arrhenius equation that considers concentration and viscosity changes.
TEXTBOOKS
Nicoli C. Shelf Life Assessment of Food (Food Preservation Technology Series). CRC Press: Boca Raton, FL (2012).
Steele R. Understanding and measuring the shelf-life of food. CRC Press: Boca Raton, FL (2004).
Kilcast D., Subramaniam P. The stability and shelf-life of food. Woodhead Publishing Ltd: Cambridge, UK (2000)
Man D., Jones A. Shelf-life evaluation of foods. Aspen Publishers Inc.: Gaithersburg, Maryland, US (2000).
INTERMEDIATE TEST
Final report of project work.
METHOD OF EVALUATION
Final report of project work.
Final exam on all the Units of the Official Programme. The final exam involves the evaluation of judgement skills in the professional environment.Evaluation and grading Percentage (%)
Project work 50
Final Exam 50 - Prerequisites:
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