1. Understanding Food
Chapter 12:
Cheese

2. Classification of Cheeses
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
The most common ways of classifying cheeses are by the:
Processing method
Milk source (cow, sheep, goat, etc.)
Moisture content

3. Classification of Cheeses
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..
Fresh They include cottage cheese, cream cheese, ricotta, farmer’s, pot, and feta cheeses.
Soft Cheeses like Brie, Camembert, and many Hispanic cheeses
Semi hard Examples are Roquefort, blue, Muenster…
Very hard Parmesan and Romano are classified among the hardest cheeses

4. Cheese Production
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.

5. Cheese Production
Milk selection has the greatest influence on classification of cheese.
Any mammal’s milk can be made into cheese.
U.S.: pasteurized cow’s milk
Europe and the Middle East: sheep’s or goat’s milk
Iran and Afghanistan: camel
Lapland: reindeer
Mongolia: horse
Philippines , India, and Italy: water buffalo
China and Tibet: yak and zebu

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. Purchasing Cheese 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).
Graded cheeses are evaluated based on their:
Variety
Flavor
Texture
Finish
Color
Appearance

16. Food Preparation with Cheese
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.

17. Food Preparation with Cheese
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

18. Storage of Cheese
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.

19. Understanding Food
Chapter 13:
Eggs

20. Composition of Eggs
Just a few examples of how eggs are used in food preparation:
Structure
Thickening
Color
Emulsifying
Leavening
Binding
Coating
Glazing
Clarifying
Giving a foam structure to cakes and meringues
Thickening custards and puddings
Adding color to lemon meringue pie and eggnog
Emulsifying mayonnaise and hollandaise sauce
Leavening soufflés and popovers
Binding ingredients in meatloafs and casseroles
Coating foods prior to breading
Glazing pastries and breads
Clarifying liquids for soups

21. Composition of Eggs The egg has five major components: Yolk
Albumen (egg white)
Shell membranes
Air cell
Shell
Each of these plays an important role in the egg’s unique attributes that make it invaluable in food preparation.

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
This law is enforced by the USDA Poultry Division and applies to all eggs, whether imported or shipped intra- or interstate.

26. Purchasing Eggs Grading
The best-quality eggs are graded USDA Grade AA, followed by USDA Grade A.
USDA Grade B, the lowest grade.
The grades sold at supermarkets.
Available to food service establishments and not sold directly to consumers.

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.
Foam- beating causes egg whites to denature (unfold). When they rearrange around air cells foam structure is created. During heat, cells expand and set when protein is coagulated.
Interfering – interfere with formation of ice crystals in frozen desserts. Smoother texture
Clarify- egg proteins (whites primarily) in clold liquid and then heated causes the proteins to solidify, attract other particles that may be clouding the liquid and to rise with them to the surface for removal. Done in soups.

33. Increased time of coagulation with dilution (milk)- increases volume, dec stability
Sugar – increased temp of coagulation add near end very fine texture
Acid- decreased temp of coagulation
Mech beating – coagulates protein (beaten egg whites)
Temp – whites best at room temperature
Beater- wire whisk, rotary beater, or electric. Hand beater best quality, electric fastest
Container- avoid plastic (hard to remove fat)
Salt – decreases stability
Sugar inhibits denaturization, stable, smooth, inc beating, very fine texture
Cr of tartar- delays, aids in stabilizing
Fat- retards formation
Soft – shiny, tips bend, slips in bowl
Stiff- won’t slip in bowl, stands up
Dry- volume starts to decrease, looks dry
Weeping due to failure to denature protein
Beading due to over baking

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.
Adding other ingredients to eggs changes their coagulation temperature.
Undesirable color changes may occur during egg preparation
Factors of Coagulation
Temperature
Whites F
Yolks F
Coagulation- clumping together of partially denatured proteins
Physical change in proteins
Form gel network
Slow rate at low temp, faster at high temp

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.
Prime (season): To seal the pores of a pan’s metal surface with a layer of heated-on oil.
Baked egg dishes include shirred eggs, meringues (both soft and hard), and soufflés.
Weeping (syneresis): The escape of liquid to the bottom of a meringue or the formation of pores filled with liquid.
Beading :The formation of tiny syrup droplets on the surface of a baked meringue.

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. Preparation of Eggs 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

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.
Whole eggs with intact shells should never be microwaved.
Steam expanding within the shell can cause them to burst.
The same principle applies to whole eggs out of the shell.
Egg yolks will burst if not punctured with a toothpick or the tip of a knife prior to going into the microwave.

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.
To ensure the freshness of whole or liquid eggs, they may be:
Refrigerated
Frozen
Dried
Use eggs promptly-3-5 wks
hard cooked - 1 week
leftover yolk & whites - 4 days
Freeze for longer use - 1 y
Handle safely
wash hands, utensils, equip & work area before and after contact with eggs

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.
Avoid eating soft-cooked or runny eggs
Use safe egg recipes F
USDA – “potentially hazardous food”
About 80% of cases from raw or undercooked eggs (cook whites till done and yolks start to thicken to be safe)
1 day at room temp = 1 week in the fridge
Shell is covered with organic material that prevents invasion of microorganisms.
Wash just prior to use if dirty.