DOMAIN I – PRINCIPLES OF DIETETICS
TOPIC A – Food, Nutrition and Supporting Sciences
1. Food science
1. Physical and chemical properties of food
a. Water
1. Function
(1) Heat-transferring agent and solvent
(2) Affects polar molecules such as sugar, starches, gums
(3) Comes in solids, liquids and gases
2. Hard Water vs. Soft Water
(1) Hard water contains a greater concentration of calcium
and magnesium
3. Factors that affect freezing and boiling water
(1) Temperature – below 32 or above 212 degrees F
(2) Addition of solutes to lower freezing points/increase
boiling point (salt/sugar)
(3) Pressure – when vapor = atmosphere pressure, water boils
i. Higher pressure, water boils faster
b. Vegetables and fruits
1. Value and structure
(1) High in water content, low in protein/fat
(2) Rich in Vitamin A, C and some B
(3) Soybean
i. Methionine is the limiting AA
ii. Used in textured protein products
2. Ripening and storage
(1) Protopectin converted to pectin (ripe fruit) then converted
to pectic acid (overripe fruit)
(2) Ethylene gas accelerates ripening of fruits during storage
(3) Avocados, bananas, pears and tomatoes ripen best at
room temperature
3. Preparation and processing
(1) Berries and mushrooms should be washed just before
serving
(2) Fruits low in vitamin C darken when cut d/t enzymatic
activity Ex. Apples
4. Grades – by USDA
(1) Based on firmness, quality, color, maturity, freedom from
defects, uniform size and shape
(2) Canned fruits and vegetables
, i. Grade A – deserts, salads(Fancy), Grade B –
processed(Choice), Grade C – puddings,
pies(Standard)
(3) Fresh Produce – Fancy, Extra #1, #1, Combination #2
c. Sugars
1. Structure types
(1) Monosaccharides – simple sugars
i. Glucose: food and blood
ii. Fructose: fruit and honey and prep
iii. Galactose: found in milk
(2) Disaccharides
i. Sucrose: glucose + fructose (table sugar)
ii. Lactose: galactose + glucose (milk)
iii. Maltose: glucose + glucose (beer and cereal)
(3) Polysaccharides
i. Digestible: starch (plants, glucagon)
ii. Undigestible: Fiber, Cellulose (peristalsis),
Pectin(jelly), Gums
(4) Sweetness(most to least) – fructose, invert sugar, sucrose,
glucose, sorbitol, mannitol, galactose, maltose, lactose
d. Flours grains, and cereals
1. Structure and Nutritional value
(1) Wheat, Germ and Endosperm
(2) Rich in Vitamin E,B, thiamin, riboflavin, phosphorus, fiber,
iron, zinc
(3) Quick cereals have disodium phosphate; high in sodium
2. Wheat flours
(1) Enriched with thiamin riboflavin, niacin, iron, folic acid
(2) Types
i. Whole wheat
ii. Bread – strong; 11.8% protein (most)
iii. All-purpose – less gluten, 10.5% protein
iv. Pastry – 7.9% protein, weak gluten
v. Cake – weakest gluten, more starch, 7.5% protein
(least)
(3) Durum wheat – high in gluten, used for pasta
e. Milk and dairy products
1. Composition and Nutritional Value of Milk
(1) 2 main milk proteins - 80% casein, 20% whey
(2) Good source of calcium, phosphorus, riboflavin, vitamin A,
D; low in vitamin C and iron
(3) Pasteurization – destroys bacteria, 145 degrees for 30 min
or 160 for 15 seconds
2. Types of milk
, (1) Homogenized (easier to digest), vitamin D milk, 2%, 1%, fat
free, concentrated milk, fermented milk, dried milk, kefir,
filled milk
i. Fermented milk – buttermilk; add lactic acid to milk
ii. Kefir – fermented by lactobacillus kefir, adds CHO
iii. Filled milk – skim milk, vegetable fat
3. Milk in food preparation
(1) When milk is heated, whey protein precipitates out on
bottom of pan and form a film
4. Butter
(1) Butter – 80% milk fat, margarine – 80% vegetable oil or
animal fat
5. Cream
(1) Highest to lowest fat – heavy, medium, whipped, light or
thin, half/half
6. Cheese
(1) Ingredients – warm milk, lactic-acid bacteria, enzyme
rennet
(2) Types
i. Uncured – refrigerate immediately (cottage cheese,
cream cheese)
ii. Cured – salt or smoke is added and
ripened/matured
iii. Processed – blend of several natural cheeses
(American)
1. Emulsifier added (disodium phosphate)
prevents fat separation and promotes
smoothness
f. Eggs
1. Structure and composition
(1) Air space increases with age; old floats, new sinks
(2) Egg yolk Is a naturally occurring oil in water emulsion
i. Surrounded by vitalline membrane, chalaza are
yolk anchors
(3) Good quality is when a high proportion of thick white
(4) Color of yolk depends on pigment in hen’s diet
2. Nutrition Value
(1) 80 calories, 6g of protein, 5 g of fat, vit A,D and riboflavin
(2) Yolk is more concentrated than white; has more protein,
fat and mineral
3. Grading
(1) Candling – pass an egg in front of bright light to view
content
(2) Grades – AA (best), A, B (low, used for liquid eggs/baking)
, 4. Preparation
(1) Leavening effects – depends on amount of air beaten in
and retained
i. An acid stiffens an egg white foam by tenderizing
the protein and extend (cream of tartar)
ii. Egg whites at room temperature whip more quickly
and yield a larger volume d/t lower surface tension
(2) Emulsification
i. Binds to other ingredients; stability more in yolk
ii. Lecithin helps yolk act as an emulsifier
(3) Custards
i. The larger % sag, the more tender the gel – the
more tender the gel, the more it will sag w/
pressure
(4) Egg substitutes
i. Lower in fat calories, cholesterol, higher in sodium
ii. Color (added carotenoid) and flavor differences
g. Meats, fish, poultry, meat alternatives
1. Structure and composition
(1) Collagen – structure part of tendon that surrounds muscle
i. In heat-hydrolyzed into protein
(2) Elastin – resistant to heat – little change in cooking
2. Nutritional Value
(1) 16-23% of protein
(2) Vitamins and minerals – thiamin, niacin, riboflavin iron,
copper, trace minerals; pork is rich in thiamin
(3) Fish has less fat and fewer calories than meat
i. Calcium is higher in fish canned with bones,
oysters, shrimp
3. Textured vegetable protein – made into similar products of meat
from soybean
(vegan)
4. Pigment – main contributor to meat color – myoglobin
(1) Red = fresh, brown/green = oxidization
5. Inspection and grading – USDA during slaughter
(1) Prime, Choice, Select, Standard
6. Cooking principles
(1) Safe temperatures
i. 145 degrees – pork, beef, veal, lamb, steaks, roast,
fish
ii. 160 degrees – ground beef, ground veal, ground
lamb
iii. 165 degrees – turkey, chicken, duck
TOPIC A – Food, Nutrition and Supporting Sciences
1. Food science
1. Physical and chemical properties of food
a. Water
1. Function
(1) Heat-transferring agent and solvent
(2) Affects polar molecules such as sugar, starches, gums
(3) Comes in solids, liquids and gases
2. Hard Water vs. Soft Water
(1) Hard water contains a greater concentration of calcium
and magnesium
3. Factors that affect freezing and boiling water
(1) Temperature – below 32 or above 212 degrees F
(2) Addition of solutes to lower freezing points/increase
boiling point (salt/sugar)
(3) Pressure – when vapor = atmosphere pressure, water boils
i. Higher pressure, water boils faster
b. Vegetables and fruits
1. Value and structure
(1) High in water content, low in protein/fat
(2) Rich in Vitamin A, C and some B
(3) Soybean
i. Methionine is the limiting AA
ii. Used in textured protein products
2. Ripening and storage
(1) Protopectin converted to pectin (ripe fruit) then converted
to pectic acid (overripe fruit)
(2) Ethylene gas accelerates ripening of fruits during storage
(3) Avocados, bananas, pears and tomatoes ripen best at
room temperature
3. Preparation and processing
(1) Berries and mushrooms should be washed just before
serving
(2) Fruits low in vitamin C darken when cut d/t enzymatic
activity Ex. Apples
4. Grades – by USDA
(1) Based on firmness, quality, color, maturity, freedom from
defects, uniform size and shape
(2) Canned fruits and vegetables
, i. Grade A – deserts, salads(Fancy), Grade B –
processed(Choice), Grade C – puddings,
pies(Standard)
(3) Fresh Produce – Fancy, Extra #1, #1, Combination #2
c. Sugars
1. Structure types
(1) Monosaccharides – simple sugars
i. Glucose: food and blood
ii. Fructose: fruit and honey and prep
iii. Galactose: found in milk
(2) Disaccharides
i. Sucrose: glucose + fructose (table sugar)
ii. Lactose: galactose + glucose (milk)
iii. Maltose: glucose + glucose (beer and cereal)
(3) Polysaccharides
i. Digestible: starch (plants, glucagon)
ii. Undigestible: Fiber, Cellulose (peristalsis),
Pectin(jelly), Gums
(4) Sweetness(most to least) – fructose, invert sugar, sucrose,
glucose, sorbitol, mannitol, galactose, maltose, lactose
d. Flours grains, and cereals
1. Structure and Nutritional value
(1) Wheat, Germ and Endosperm
(2) Rich in Vitamin E,B, thiamin, riboflavin, phosphorus, fiber,
iron, zinc
(3) Quick cereals have disodium phosphate; high in sodium
2. Wheat flours
(1) Enriched with thiamin riboflavin, niacin, iron, folic acid
(2) Types
i. Whole wheat
ii. Bread – strong; 11.8% protein (most)
iii. All-purpose – less gluten, 10.5% protein
iv. Pastry – 7.9% protein, weak gluten
v. Cake – weakest gluten, more starch, 7.5% protein
(least)
(3) Durum wheat – high in gluten, used for pasta
e. Milk and dairy products
1. Composition and Nutritional Value of Milk
(1) 2 main milk proteins - 80% casein, 20% whey
(2) Good source of calcium, phosphorus, riboflavin, vitamin A,
D; low in vitamin C and iron
(3) Pasteurization – destroys bacteria, 145 degrees for 30 min
or 160 for 15 seconds
2. Types of milk
, (1) Homogenized (easier to digest), vitamin D milk, 2%, 1%, fat
free, concentrated milk, fermented milk, dried milk, kefir,
filled milk
i. Fermented milk – buttermilk; add lactic acid to milk
ii. Kefir – fermented by lactobacillus kefir, adds CHO
iii. Filled milk – skim milk, vegetable fat
3. Milk in food preparation
(1) When milk is heated, whey protein precipitates out on
bottom of pan and form a film
4. Butter
(1) Butter – 80% milk fat, margarine – 80% vegetable oil or
animal fat
5. Cream
(1) Highest to lowest fat – heavy, medium, whipped, light or
thin, half/half
6. Cheese
(1) Ingredients – warm milk, lactic-acid bacteria, enzyme
rennet
(2) Types
i. Uncured – refrigerate immediately (cottage cheese,
cream cheese)
ii. Cured – salt or smoke is added and
ripened/matured
iii. Processed – blend of several natural cheeses
(American)
1. Emulsifier added (disodium phosphate)
prevents fat separation and promotes
smoothness
f. Eggs
1. Structure and composition
(1) Air space increases with age; old floats, new sinks
(2) Egg yolk Is a naturally occurring oil in water emulsion
i. Surrounded by vitalline membrane, chalaza are
yolk anchors
(3) Good quality is when a high proportion of thick white
(4) Color of yolk depends on pigment in hen’s diet
2. Nutrition Value
(1) 80 calories, 6g of protein, 5 g of fat, vit A,D and riboflavin
(2) Yolk is more concentrated than white; has more protein,
fat and mineral
3. Grading
(1) Candling – pass an egg in front of bright light to view
content
(2) Grades – AA (best), A, B (low, used for liquid eggs/baking)
, 4. Preparation
(1) Leavening effects – depends on amount of air beaten in
and retained
i. An acid stiffens an egg white foam by tenderizing
the protein and extend (cream of tartar)
ii. Egg whites at room temperature whip more quickly
and yield a larger volume d/t lower surface tension
(2) Emulsification
i. Binds to other ingredients; stability more in yolk
ii. Lecithin helps yolk act as an emulsifier
(3) Custards
i. The larger % sag, the more tender the gel – the
more tender the gel, the more it will sag w/
pressure
(4) Egg substitutes
i. Lower in fat calories, cholesterol, higher in sodium
ii. Color (added carotenoid) and flavor differences
g. Meats, fish, poultry, meat alternatives
1. Structure and composition
(1) Collagen – structure part of tendon that surrounds muscle
i. In heat-hydrolyzed into protein
(2) Elastin – resistant to heat – little change in cooking
2. Nutritional Value
(1) 16-23% of protein
(2) Vitamins and minerals – thiamin, niacin, riboflavin iron,
copper, trace minerals; pork is rich in thiamin
(3) Fish has less fat and fewer calories than meat
i. Calcium is higher in fish canned with bones,
oysters, shrimp
3. Textured vegetable protein – made into similar products of meat
from soybean
(vegan)
4. Pigment – main contributor to meat color – myoglobin
(1) Red = fresh, brown/green = oxidization
5. Inspection and grading – USDA during slaughter
(1) Prime, Choice, Select, Standard
6. Cooking principles
(1) Safe temperatures
i. 145 degrees – pork, beef, veal, lamb, steaks, roast,
fish
ii. 160 degrees – ground beef, ground veal, ground
lamb
iii. 165 degrees – turkey, chicken, duck
