FScN 8334
Reaction Kinetics of Food Deterioration

Instructor:  Dr Ted Labuza

Office: 136 ABLMS St Paul Campus
Phone: 612-624-9701 Cell phone 651-307-2985
Fax: Office 612-625-5272 Home office 651-483-3302
email tplabuza@umn.edu
Office Hours : open hours or by appointment

Lecture Room 223 ABLMS Thursday 11:45 to 1:40

Go to Course lecture material in pdf format

Links to reading material

Link to problem sets

Student Class Questions and email questions page

Link to graphs and spreadsheets

Link to papers for Group Presentation

Go to Course Final Research Proposal

Course Web  http://www.ardilla.umn.edu/00fscn8334-1f/

Course Syllabus

Course Description

Review of the basis for use of applied chemical kinetics to deteriorative reactions occurring in the processing and storage of foods and drugs. Specific systems covered include basic and applied principles including temperature effects, frozen state degradation, lipid oxidation, non-enzymatic browning, shelf life test design and TTIs. Application of these kinetics to the study of accelerated shelf life testing and storage losses of foods, drugs, and biologics and selection of open dates or expiration dates.

Student Performance Objectives

To apply principles of chemical kinetics to the analysis of rates of deterioration of foods and/or drugs.

To use these principles to understand accelerated shelf life testing procedures

To use these principles to evaluate the validity of research publications with respect to deterioration of foods.

To learn to use proper kinetic principles, statistics and mathematical models in graduate thesis research

Course Outline

Shelf life testing and open dating- 2 lectures

Determination of reaction rates, rate constants and reaction order and computer modeling of kinetic data- 2 lectures

Activation energy and Q10 Concept. Time temperature integration- 2 lectures

Examples of zero and first order kinetics (variable temperature, frozen foods and NEB)- 3 lectures

Microbial growth and death kinetics 2 lectures

Lipid oxidation kinetics - 1 lecture

TTIs 1 lecture

Shelf Life design and sensory evaluation 2 lectures

Lecture schedule (subject to change)

1. January 18

Topic 1 Intro to shelf life and open dating

2. January 25

 Topic 1 continued sources of data and Q₁₀ concept

3.  February 1

Topic 2 Reaction Order

Group A Paper review Presentation

4. Feb 8

Topic 2 Reaction order and rate constants  continued

Group D  Open date Label Presentation

Problem set #1 due

5.  February 15

Topic 3 Temperature dependence models

Group C  Open date Presentation

6. February 22

Topic 3 Temperature Effect on reaction rates,  continued

Group A  Open date Label  Presentation

7. March 1

Topic 4 Frozen Food Shelf life

Group B Paper review presentation

Problem Set #2 due

8. March 8

Topic 5    Water activity and Tg  effects on rate

Group B Open Date Label Presentation

9. March  22

Topic 6 Growth  kinetics and safety based shelf life

10. March 29

Topic 7 Death Kinetics

11. April 5

Topic 8 Non-enzymatic Browning kinetics

Problem Set # 3 due

12. April 12

Topic 9  Free Radical Kinetics Lipid Oxidation

13. April 19

 Topic 10 Shelf Life Test Design

Group C Paper Review Presentation

14. April 26

  Topic 11  TTI kinetics

Problem Set # 4 due

15. May 1

Topic 12  Sensory Testing in Shelf Life

Group D Paper Review Presentation

Course Assignments 

One 2 hour lecture, discussion and problem solving session each week, supplemented with required homework problems and discussion of current literature in class.

Homework - 4 sets @ 25 points each, total 100 points

Open dating Group assignment 50 points

Written critique (50 points) and oral presentation (50 points) of one research paper by group (Total 100 points)

In-Class questions ( 6 required @ 5 points each) 30 points

e-mail questions ( 4 required @ 4 points = 20 points)

Final analysis of a research proposal on shelf life testing (subject to change)

Total 100% 400 points

see below for more detail on each assignment

Textbooks:

Course material on www

Supplemental Textbooks:

Shelf Life of Foods. T. P. Labuza. 1982. Food and Nutrition Press Inc.

Any general kinetics textbook book for review

OTA Open Shelf Life Testing of Foods, U.S. GPO #052-003-00694-4

Course Assignments details

1. Problem sets ( 4 x 25 = 100 points) Go to problem set page

There will be 4 problem sets , one due about every third week covering the prior material. Each will consist of 2 to 4 problems and each set will be worth 25 points but may not be of equal work. Neatness counts. Use a good graphics program , a computer for written material and a good program such as Excel, Sigma Plot. Math CAD, etc. Do not write on two sides and put the graphs, tables etc in order in the answer, not at the end of the whole packet handed in.

2. Open dating assignment (50 points)

I would like for each group to take the assigned food category below and visit a supermarket (or several of them ) and get specific information on any open date labeling that are on at least 3 different product types in that category as noted and for at least three competitors if possible in each of those product types in the category. Then on Sept 28th each group will present what they have found and make oral comments on what it means (why do you think the company chose the right open dating system they use; what does the literature data say about shelf life, what are the problems) maximum 10 minutes. I would like a Power Point presentation of each group.

Group A Shelf Stable meals in microwaveable plastics)

        Otte, Long, Zhang

Group B RTE meats (hot dogs, luncheon meats, semi-dry sausage)

     Leclerq, Lee, Charve

Group C Refrigerated CAP/MAP meals (components)

      Pal, Folts

Group D Nutritional Bars

     Nechrebecki, Ayd

3. Written and Oral Critique of research paper by groups (1 paper each group = 100 points

Link to papers for Group Presentation

The criteria for the written critique of each research paper is listed below. Each group will critique one paper but everyone is responsible for reading all four papers. The critique should be no more than 4 pages, (word processor 12 point, max 1” margins; graphs, tables and computer output not included)

The following points should be covered in the paper (50 points):

1. What was the hypothesis of the study ? If there was none stated, determine what it should have been. (5 points)

2. What were the objectives used to test the hypothesis ? Are these the right ones? (5 points)

3. Did they adequately discuss the literature (Note the date of publication, obviously they could not site newer papers? (5 points)

4. Did they use a good experimental design to meet the objective? If what should they have done, e.g. # of data points? (10 points)

5. How did they report their results ? Would there be a better way? Can others use their data? Make better graphs for them. (5 points)

6. What model did they use to analyze the data kinetically?

Was this a good model, why or why not?

Did they violate any kinetic rules?

If the answer is that they used a poor model what should they have done. Make the correct analysis. Estimate any data points if needed. (10 points)

7. Was the hypothesis supported by the work? Discuss (5 points)

8. Did they have an adequate discussion of the importance of the results, i.e. is there anything important to learn from the study that they said or that you have found? (5 points)

For the oral presentation (50 points)

1.  Power Point presentation ( make copy for instructor)

2. Each group member should make part of the oral presentation unless you get permission otherwise

3. It will be limited to 20 minutes plus 10 minutes for class and instructor questions

4. Grading will be based on the average of the students scores and the instructor's score using the following points

general organization of the presentation 10 points

quality of overheads or power point presentation 10 points

oral style of presenters - 10 points

conciseness and understandability of the presentation - 10 points

sticking to time 5 points

ability to handle questions 5 points

4. Class participation questions (6 @ 5 points = 30 points) Go to class question page

There  will be up to 5 points awarded for bringing up any good point or question during class or during the discussion especially during the paper presentations. Each student must ask at least 6 very good questions during the semester for a total of 30 points. Each student will be responsible for submitting the question by email to the instructor by Sunday 6 PM after the class day  with a synopsis of the question, the answer given and any comments that the question stimulated. No late submissions accepted.

5. e-mail questions ( 4 @ 5 points each = 20 points) Go to email question page

From time to time the instructor will send out to the class, a question asked from several food science based Listservs that have relevance to the course. The student must submit a written answer (by email) before the next class period. Students who have answered the question may volunteer to present the question/answer in the following class for extra credit (up to 10 points each

6. Critique of a research proposal on shelf life It will be handed out in the 12th week of the course 100 points

NOTE 1: A computer program in Macintosh HyperCard to do kinetics will be made available to all students. Please bring in a disk to copy it in the lab in 161 ABLMS. A sample set of data is in the program.

NOTE 2: Bring graph paper (linear and 2 and 3 log cycle) to class each time for any problems to be done. Also bring a straight edge (prefer 12" clear plastic triangle and a scientific calculator.

GRADING POLICY:

University of Minnesota

University of Minnesota Senate

Definitions of Grades and Academic Work Load Expectations

A Represents achievement that is outstanding relative to the level necessary to meet course requirements.

B Represents achievement that is significantly above the level necessary to meet course requirements.

C Represents achievement that meets the course requirements in every respect.

D Represents achievement that is worthy of credit even though it fails to meet fully the course requirements.

S Represents achievement that is satisfactory, which is equivalent to a C- or better.

There are two permanent grades given for a single course for which no credit shall be awarded and which will be entered on a student's official transcript:

F Represents failure and signifies that the work was either

1. completed but at a level of achievement that is not worthy of credit or
2. was not completed and there was no agreement between the instructor and the student that the student would be awarded an I (incomplete).

N Represents no credit and signifies that the work was either

(1) completed but at a level of achievement that is not worthy of credit or

(2) was not completed and there was no agreement between the instructor and the student that the student would be awarded an I.

The F carries 0 grade points and the credits for the course do not count toward any

academic degree program. The credit hours for the course shall count in the grade point average.

The N carries no grade points and the credits for the course do not count toward any academic degree program. The credit hours for the course do not count in the grade point average.

Academic dishonesty in any portion of the academic work for a course shall be grounds for awarding a grade of F or N for the entire course.

One conventional credit is hereby defined as equivalent to three hours of learning effort per week, averaged over an appropriate time interval, necessary for an average student taking that course to achieve an average grade of C in that course.

Go to class roster

Go to Course lecture material in pdf format

Links to reading material

Link to problem sets

Student Class Questions and email page

Course Final Page

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