Understanding Food

1. Understanding Food Chapter 12: Cheese

2. They can be defined by their: Microbial characteristics Appearance Mode of packaging Place of origin The most common ways of classifying cheeses are by the: Processing method Milk source (cow, sheep, goat, etc.) Moisture content Classification of Cheeses

3. Cheeses classified according to their moisture content: Fresh.Moisture content is over 80%, and they are not aged. Soft.Water content ranges from 50 to 75% and are aged for just a short time.. Semi-hard.40 to 50% moisture. Hard.The moisture content ranges from 30 to 40%. Cheddar and Swiss are examples. Very hard.Water content of approximately 30% and are aged the longest.. Classification of Cheeses

4. No two cheese varieties are produced by exactly the same method, but the basic steps common to them all include: Milk selection Coagulation Curd treatment Curing Ripening The yield from 10 pounds of milk is approximately 1 pound of cheese and 9 pounds of whey. Cheese Production

5. Cheese Production • Milk selection has the greatest influence on classification of cheese. • Any mammal’s milk can be made into cheese.

6. Cheese Production • Cheese-making starts with the coagulation of the casein protein in milk. • The type of method used determines many of the characteristics of the resulting cheese. • The two main methods to aid coagulation are the action of: • Enzymes • Acid

7. Cheese Production • The curd produced by acid has a soft and spongy texture. • This texture is influenced by pH, becoming more solid and compact as the acidity increases.

8. Cheese Production • The curd may be treated to remove more whey by: • Cutting • Heating • Salting • Further optional treatment includes knitting and/or pressing

9. Cheese Production • Curing: To expose cheese to controlled temperature and humidity during aging. • Ripening:The chemical and physical changes that occur during the curing period.

11. Cheese Production • Processed cheese:A cheese made from blending one or more varieties of cheese, with or without heat, and mixing it with other ingredients.

12. Grading USDA-defined U.S. Grades AA, A, B, and C. Graded cheeses are evaluated based on their: Variety Flavor Texture Finish Color Appearance Exceptions to these criteria are: Colby cheese, in which color is not considered. Swiss cheese, which is graded additionally for its salt level and eyes (holes). Purchasing Cheese

16. Cheese is most often used as an ingredient to add: Flavor Color Texture …in a variety of ways—on pizza, in a taco, etc. The two most important principles when preparing foods with cheese are: Select the best cheese. Keep temperatures low and heating times short. Food Preparation with Cheese

17. Selecting a Cheese The chemical composition of a cheese determines its functional properties and dictates how it will be used in food preparation. Some of these functional properties include: Shredability Meltability Oiling off Blistering Browning Strechability Food Preparation with Cheese

18. Cheese must be stored properly to prevent deterioration. Most cheeses should be refrigerated. Some can even be frozen. Processed cheese products can be stored in a cool, preferably dark, cupboard until ready for use... Though refrigeration more effectively retains desirable qualities. Storage of Cheese

19. Understanding Food Chapter 13: Eggs

20. Just a few examples of how eggs are used in food preparation: Structure Thickening Color Emulsifying Leavening Binding Coating Glazing Clarifying Composition of Eggs

21. Composition of Eggs • The egg has five major components: • Yolk • Albumen (egg white) • Shell membranes • Air cell • Shell

23. Composition of Eggs • Chalaza (pl. chalazae):The ropy, twisted strands of albumen that anchor the yolk to the center of the thick egg white. • Vitelline membrane:The membrane surrounding the egg yolk and attached to the chalazae. • Cuticle (bloom):A waxy coating on an eggshell that seals the pores from bacterial contamination and moisture loss.

24. Composition of Eggs

25. Purchasing Eggs Inspection • The Egg Products Inspection Act of 1970 requires that egg processing plants be inspected and that their eggs and egg products be: • Wholesome • Unadulterated • Truthfully labeled

26. Purchasing Eggs Grading • The best-quality eggs are graded USDA Grade AA, followed by USDA Grade A. • USDA Grade B, the lowest grade.

28. Purchasing Eggs • Candling:A method of determining egg quality based on observing eggs against a light.

29. Purchasing Eggs Haugh Units • The freshness of an egg can be detected by cracking it open onto a flat surface and looking at the height of its thick albumen. • Fresh egg whites sit up tall and firm, while older ones tend to spread out.

30. Purchasing Eggs • Sizing is not related to grading in any way. • Eggs are sold in cartons by various sizes determined by a minimum weight for a dozen eggs in their shell.

31. Purchasing Eggs

32. Functions of Eggs in Foods • Eggs are often combined with other ingredients. • Their unique ability to: • Flavor • Color • Emulsify • Thicken • Bind • Foam • Interfere • Clarify …makes them nearly indispensable in cooking.

34. Functions of Eggs in Foods • Clarify:To make or become clear or pure.

35. Preparation of Eggs Changes in Prepared Eggs • The key to cooking eggs is to keep the temperature low and/or the cooking time short. • Egg whites and yolks coagulate at different temperatures.

36. Preparation of Eggs • Dry-heat preparation of eggs primarily involves frying and baking. • Egg dishes that are commonly fried are fried eggs, scrambled eggs, and omelets.

37. Preparation of Eggs Moist-Heat Preparation • Eggs can be prepared by moist heat using a variety of methods. • Most common among these are: • “Boiled” eggs • Coddled eggs prepared in a cup • Poached eggs • A variety of custards • Eggs that are prepared using the microwave • In all cases, eggs are cooked at simmering temperatures.

38. Hard or Soft “Boiled” Hot-Start Method: Soft: 3 to 4 minutes Medium: 5 to 7 minutes Hard: 12 to 15 minutes Cold-Start Method: Soft: 1 minute Medium: 3 to 5 minutes Hard: 10 minutes Preparation of Eggs

39. Preparation of Eggs Microwaving • Eggs cook extremely rapidly in a microwave oven. • Special caution should be taken to avoid overcooking. • Manufacturer’s instructions should be followed for microwave egg cooking.

40. Storage of Eggs • Eggs begin to deteriorate as soon as they are laid and lose quality very rapidly at room temperature. • An egg will age more in one day at room temperature than in one week in the refrigerator.

41. Storage of Eggs • The size of an egg’s air cell provides another indication of its age.

42. Storage of Eggs Frozen • Freezing a whole egg is not possible because it will crack under the expanding liquids. • Food manufacturers solve this dilemma by breaking the eggs open at the processing plants where the contents are frozen • Whole (whites and yolk mixed together) • Separated as whites or yolks

43. Storage of Eggs Safety Tips • The chances of an egg being internally contaminated are relatively low, less than one in 10,000 commercial eggs. • It is more common for contamination to occur during handling and preparation after the egg has been removed from its shell.