Food Lipids Previous Exam III

University of Kentucky, Department of Animal & Food Sciences, FSC 640

1. Describe the polymerization of frying oil by both thermal and oxidation mechanisms. (10 pts.)

2. Describe the importance of total polar material to a frying oil, the analysis of total polar materials and the limitations of this analysis. (10 pts.)

3. Describe an external heat exchanger heating system on a fryer and three advantages this system has over a direct heating system. (10 pts.)

4. Describe the Hydrophilic-Lipohilic Balance system and how it would be expected to relate to each of the following products (Mayonnaise, Margarine, and Ice Cream). (10 pts.)

5. Describe two distinctly different ways that surfactants are used in bakery products and the proposed mechanisms for their action. (10 pts.)

6. What is shortening plasticity and how is this important to the quality of bakery products? (10 pts.)

7. Describe the typical fatty acids found in milk and their general distribution in milk triglycerides.

(10 pts.)

8. What are the major lipid components of the milk fat globule membrane and what is their general orientation in the membrane? ( 10 pts.)

9. What type of information is provided by infrared spectroscopy? Give two distinctly different applications where infrared spectroscopy could provide beneficial information . (10 pts.)

10. Discuss the difference between the oxidation of fatty acids by autoxidation, a copper catalyzed reaction and a lipoxygenase catalyzed reaction. Compare the activation energy, relative reaction rates, specificity and initial products of each reaction mechanism . (10 pts)