Sugar

1
Sugar
2
Sugar Structure

• Most simple carbohydrate
• Also called saccharides
• Composed of C, H, O
• Basic Structure (C6H12O6)

3
Types of Sugars

• Two types of sugars
• Monosaccharides (one sugar)
• Cannot be broken down further
• Disaccharides (two sugars)
• Most consumed sugars in the world
• Contain two monosaccharides joined by an alpha
  bond
• Can be broken into two monosaccharides hydrolysis

4
Types of Monosaccharides

• Glucose
• Most abundant sugar not very sweet
• Found in blood
• Fructose
• Sweeter than glucose
• Found in fruits and honey
• High-fructose corn syrup -- glucose molecules
  converted to fructose to increase sweetness -
  used commercially

5
Types of Monosaccharides

• Galactose
• Not as sweet as fructose
• Basic sugar found in milk

6
Types of Disaccharides

• Maltose
• Least sweet of the disaccharides
• Glucose and glucose bonded together
• Found in malted grains
• Lactose
• Glucose and galactose bonded together
• Found in milk

7
Types of Disaccharides

• Sucrose (table sugar)
• Glucose and fructose bonded together
• Very sweet

8
(No Transcript)
9
Functions of Sugar in Food
10
Functions of Sugar

• Sugar is a simple carbohydrate.
• Sugar has six main functions in food
• Sweetener
• Preservative
• Tenderizer
• Crystallization
• Caramelization
• Fermentation

B-3.02 -- Functions of Sugar in Food
10
11
Sweetener

• Level of sweetness in food
• Fructose is the most sweet.
• Lactose is the least sweet.
• Sweeter the sugar the more simple the molecule.
  

B-3.02 -- Functions of Sugar in Food
11
12
Preservative

• Sugar helps prevent food spoilage.
• Hygroscopic attracts water.

B-3.02 -- Functions of Sugar in Food
12
13
Tenderizer

• Sugar helps tenderize dough.
• Sugar inhibits gluten formation.
• Increases flow properties of batter.

B-3.02 -- Functions of Sugar in Food
13
14
Crystallization

• Common in candy making.
• Control so have a good quality product.

B-3.02 -- Functions of Sugar in Food
14
15
Factors that Affect Crystallization

• Five factors produce finer sugar crystals in
  candy
• Type of sugar -- sucrose
• Interfering agents - corn syrup, butter,
  acid,invert sugars
• Agitation -- beating and stirring of candy
  solution
• Cooling approximately 45?C before agitation
• Ripening -- forms a creamy, smooth texture

B-3.02 -- Functions of Sugar in Food
15
16
Caramelization

• Sugar changes into a brown liquid
• Exposed to prolonged heat
• Dehydration of water
• Flavor changes
• Examples
• Brown crust on baked goods
• Evaporated milk

B-3.02-Functions of Sugar in Food
16
17
Fermentation

• Sugar serves as the food supply for
  microorganisms.
• Used to make beer and yeast breads.

B-3.02 -- Functions of Sugar in Food
17
18
(No Transcript)
19
Complex Carbohydrates
20
Complex Carbohydrates

• Many monosaccharides linked together.
• Called polysaccharides.
• Found in grains, seeds, nuts, fruits, vegetables.
• Types include
• Starches
• Cellulose
• Gums
• Pectins

B-3.02 -- Complex Carbohydrates
20
21
Starch

• Most abundant complex carbohydrate
• Many glucose units bonded together

B-3.02 -- Complex Carbohydrates
21
22
Types of Starch

• Two basic structures in plant
• Amylose
• Linear
• Found in wheat and corn
• Amylopectin
• Branched
• Found in roots and tubers
• Most foods have a combination of both.
• Ratio affects the way the starch functions in
  food.

B-3.02 -- Complex Carbohydrates
22
23
Starch

• Found in
• Cereals/grains
• Corn
• Oats
• Wheat
• Rice
• Other plant foods
• Potatoes
• Beans/legumes

B-3.02 -- Complex Carbohydrates
23
24
Cellulose

• Many glucose units bonded together
• Beta (?) bonds
• Insoluble fiber
• Forms rigid structure of plants
• Provides texture in fruits and vegetables

B-3.02 -- Complex Carbohydrates
24
25
Gums

• Soluble fiber
• Function
• Thicken and stabilize mixtures
• Trap flavor and color
• Examples
• Salad dressings
• Ice cream
• Gummy bears

B-3.02 -- Complex Carbohydrates
25
26
Pectins

• Soluble fiber
• Naturally occurring in fruits
• Amount depends on ripeness of fruit
• Decrease ripeness, increase pectin
• Produce strong gels, such as jams and jellies

B-3.02 -- Complex Carbohydrates
26
27
(No Transcript)
28
Functions of Complex Carbohydrates

• Starch, cellulose, pectins, and gums

29
Functions

• Structure
• Binding Agent
• Thickening Agent

B-3.02 -- Functions of Complex Carbohydrates
29
30
Structure

• Starch
• Main component of wheat flour
• Provides structure to baked foods and other foods
• Thickens when heated
• Forms gel when cool
• Cellulose
• Texture in fruits and vegetables
• Pectins
• Structure of jams and jellies
• Gums

B-3.02 --Functions of Complex Carbohydrates
30
31
Binding Agent

• Binding agents hold two products together.
• Two examples
• Amylose
• Binds batter to vegetables and meats
• Carageenan Gum
• Binds cocoa in chocolate milk
• Stabilizes ice cream

B-3.02 -- Functions of Complex Carbohydrates
31
32
Thickening Agent

• Thickens liquids
• First heat to increase thickening power.
• Gelatinization
• Allows starch molecule to open and absorb water.
• Starch loses thickening power with an increase of
  heat and time.
• Salt and sugar compete for water and interfere
  with gelatinization.
• Startch
• sauces
• Pectins
• Used to thicken or gel jams and jellies.
• Gums
• Used to thicken salad dressings, puddings and ice
  creams.

B-3.02 -- Functions of Complex Carbohydrates
32
33
(No Transcript)
34
Physical Properties of Starch
35
Considerations

• Five properties to consider when choosing a
  starch for food preparation
• Retrogradation
• Viscosity
• Stability
• Opacity vs. Translucency
• Texture

B-3.02 -- Physical Properties of Starch
35
36
Retrogradation

• Firming of a gel during cooling and standing
• Amylose-amylose bonding
• Desirable when forming a gel
• Undesirable when gel cracks upon standing
• Cracks in a custard pie
• Effect of acids
• Breaks down starches and weaken gels.
• Should be added to a starch mixture after it has
  thickened.

B-3.02-Physical Properties of Starch
36
37
Retrogradation

• Syneresis
• Water leaking from a gel due to prolonged
  storage.

B-3.02 -- Physical Properties of Starch
37
38
Viscosity

• Resistance of a mixture to flow
• Starches hold their shape, resist flow
• Example -- flow of water vs. starch paste
• More starch, greater resistance to flow
• Amylose vs. amylopectin

B-3.02 -- Physical Properties of Starch
38
39
Stability

• The ability of a thickened mixture to remain
  constant over time and temperature changes
• Freezing
• Heating
• Waxy maize starch
• Flour
• Cornstarch

B-3.02 -- Physical Properties of Starch
39
40
Opacity vs. Translucency

• Opacity
• How much an object blocks light
• Wheat starch
• Good for sauces and soups
• Translucency
• How much light can pass through an object
• Cornstarch, potato starch, arrowroot
• Good for fruit sauces, pie fillings, glazes

B-3.02 -- Physical Properties of Starch
40
41
Texture

• Consider type of starch
• Gritty vs. smooth texture
• Mouthfeel

B-3.02 -- Physical Properties of Starch
41
42
(No Transcript)
43
Lipids
44
Basics

• Contain carbon, hydrogen, and oxygen.
• Insoluble in water
• Greasy feel
• Do not provide structure to foods.
• Examples
• fats, oils, shortening, phospholipids,
  cholesterol are examples

B-3.02 -- Lipids
44
45
Types of Lipids

• Three types
• Glycerides
• Phospholipids
• Sterols

B-3.02 -- Lipids
45
46
Glycerides

• Glycerides are composed of two units
• Glycerol backbone
• Fatty acids

B-3.02 -- Lipids
46
47
Forms of Glycerides

• Monoglycerides have one fatty acid
• Diglycerides have two fatty acids
• Mono- and diglycerides are partially soluble in
  water
• Added to processed foods to prevent oxidation
• Important in the food industry
• Triglycerides have three fatty acids
• Most common lipid in foods

B-3.02 --Lipids
47
48
Phospholipids

• A glycerol with two fatty acids one acid that
  contains a phosphorus
• Phosphorus containing acid dissolves in water
• Fatty acids are soluble in fats
• Structure allows phospholipids to mix with both
  water and fat-based substances
• Used in the food industry as an emulsifier
• Lecithin in egg yolks is an example

B-3.02 -- Lipids
48
49
Sterols

• Complex molecules made from fatty acids
• Cholesterol
• Found in animal-based foods
• Not found in plant-based foods
• Vitamin D
• Fortified milk

B-3.02 -- Lipids
49
50
Categorizing Lipids

• Based on structure
• Unsaturated fatty acids
• one or more double bonds
• Saturated fatty acids
• All single bonds
• more stable to chemical breakdown

B-3.02 -- Lipids
50
51
Categorizing Lipids

• Based on physical state.
• Fats
• Solid at room temperature
• High in saturated fatty acids
• Oils
• Liquid at room temperature
• High in unsaturated fatty acids
• Hydrogenation
• Increase hydrogen atom content to turn oils to
  solid.

B-3.02 -- Lipids
51
52
(No Transcript)
53
Characteristics of Lipids
54
Characteristics

• Characteristics include
• Melting point
• Solidification point
• Non-polar molecular
• Rapid deterioration

B-3.02 -- Characteristics of Lipids
55
Melting Point

• Lipids do not have a specific melting point.
• Mixture of fatty acids
• Saturated vs. unsaturated fatty acids in lipids
• Different melting points

B-3.02 -- Characteristics of Lipids
56
Solidification Point

• Lipids in a mixture solidify at different
  temperatures.
• Solidification point
• Temperature at which all lipids in a mixture are
  in a solid state.
• Lipids solidify rather than freeze.

B-3.02 -- Characteristics of Lipids
57
Solidification vs. Melting Point

• If an oil is 60 monounsaturated fat, 25
  polyunsaturated fat, and 15 saturated fat,
  different lipid molecules will solidify at
  different temperatures.
• Example
• Saturated fats will start to solidify first.
• Polyunsaturated molecules will not completely
  solidify until the temperature drops 3 or 4 more
  degrees.

B-3.02 -- Characteristics of Lipids
58
Nonpolar Molecules

• Lipids molecules are nonpolar.
• Water molecules are polar.
• Polar and nonpolar molecules
• Do not attract dissimilar molecules
• Which is why oil (nonpolar) and water (polar) do
  not mix.

B-3.02 -- Characteristics of Lipids
59
Rapid Deteriorate

• Autooxidation
• Lipids exposed to oxygen
• Causes lipids to deteriorate
• Unsaturated oils more susceptible
• High-fat foods become rancid
• Rancidity
• Form of food spoilage, no health risks
• Unpleasant odor and flavors
• Minimizing autooxidation
• Vacuum-seal remove oxygen
• Antioxidants preservative that binds with oxygen

B-3.02 -- Characteristics Affecting Lipids
60
(No Transcript)
61
Functions of Lipids in Food
62
Transfer Heat

• Excellent heat medium -- allows foods to brown
  unlike water
• Prolonged heating
• Lipids break apart -- produce smoke, which is
  called smoke point.
• Undesirable color and flavor changes then occur
  in food
• At this point, discard oil
• Flash Point -- oil hot enough to flame.

B-3.02 -- Functions of Lipids in Food
62
63
Smoke Point

• Point at which oil begins to smoke
• 510oF -- Safflower
• 495oF -- Soybean
• 475oF -- Corn
• 440oF -- Peanut
• 375oF Olive oil
• 375oF -- Shortening

B-3.02 -- Functions of Lipids in Food
63
64
Tenderize

• Tenderizes baked product
• Liquid vs. solid fat
• Solid fats shortens gluten strands better than
  liquid fats so more tender product
• Fats with high melting point
• Can be worked longer without melting
• Provides a more tender baked product

B-3.02 -- Functions of Lipids in Food
64
65
Aeration

• Addition of air into a batter
• Saturated fats trap air, increases volume
• Oils do not trap air
• Produces grainy texture in baked goods
• Creaming fat and sugar
• decreases viscosity
• Batter is more viscous

B-3.02 -- Functions of Lipids in Food
65
66
Enhance Flavor

• Desirable flavors
• Olive oil
• Butter
• Flavorless
• Wanted for frying
• Cottonseed oil

B-3.0 -- Functions of Lipids in Food
66
67
Lubricate

• Lubricates food components
• Easier to chew
• Pleasant mouth feel
• Makes foods seem moister

B-3.02 -- Functions of Lipids in Food
67
68
Liquid in Emulsions

• Emulsion
• A mixture that contains a lipid and a water-based
  liquid
• Lipids are usually one of the 2 liquids
• May not be permanent
• Examples
• Mayonnaise
• Butter
• Milk

B-3.02 -- Functions of Lipids in Food
68
69
(No Transcript)
70
Proteins
71
Proteins

• Composed of
• carbon
• oxygen
• hydrogen, plus
• nitrogen and sometimes sulfur
• Primary sources of essential amino acids are
  animal-based foods.

B-3.02 -- Proteins
71
72
Structure of Proteins

• Basic unit is an amino acid.
• Dipeptide
• Two amino acids joined by a peptide bond
• Polypeptide (protein)
• Active in coiled form
• Many amino acids
• peptide bonds

B-3.02 -- Proteins
72
73
Protein Quality

• Complete proteins
• Animal sources -- exception is soy and quinoa
• Higher quality
• Contain all essential amino acids
• Incomplete proteins
• Plant sources -- exception is gelatin
• Lower quality
• Missing one or more essential amino aids
• Limiting amino acid

B-3.02 -- Proteins
73
74
(No Transcript)
75
Denaturation of Protein
76
Denaturation of Protein

• Any change in the shape of a protein without
  breaking peptide bonds.
• Forms precipitates.
• Changes solubility of protein.
• Reversible
• If denaturation is slight
• Example is beaten egg whites
• Irreversible
• More common
• Examples
• Coagulation of egg white upon heating
• Clotting of milk to form curds

B-3.02 -- Denaturation of Protein
76
77
Methods of Denaturation

• Temperature Changes
• Heat
• Increase in heat increases rate of denaturation
• Frozen foods
• Physical Methods
• Mechanical Action -- beating, rolling, kneading
• Sound Waves
• Irradiation

B-3.02 -- Denaturation of Protein
77
78
Methods of Denaturation

• Chemical Methods
• Changes in pH
• Acids
• Bases (Alkalis)
• Adding metals, such as calcium
• Adding mineral salts, such as sodium and potassium

B-3.02 -- Denaturation of Protein
78
79
(No Transcript)
80
Functions of Proteins
81
Functions of Proteins

• Forms gels
• Texturizes
• Emulsifiers
• Produce foams
• Develops gluten

B-3.02 -- Functions of Proteins in Food
81
82
Forms Gels

• Protein gels
• Mostly fluids locked in a three-dimensional mesh
• Narrow melting and solidification range
• Gels form between 50-61oC
• Gels strengthened by
• Concentration of gelatin
• Mineral salts
• Gels weakened by
• Acid
• Sugar
• Fruit or vegetable pieces

B-3.02 -- Functions of Proteins in Food
82
83
Texturizes

• Protein texture/feel can be changed by
  denaturation
• Texturized soy proteins (meat substitute)
• Processed cheeses

B-3.02 -- Functions of Proteins in Food
83
84
Emulsifies

• Stable mixture of a fat and a water-based liquid
• Proteins stabilize emulsions by acting as an
  emulsifier
• Emulsifiers are molecules with polar and nonpolar
  end
• Allows water and oil-based liquids to mix
• Examples milk, cream, butter, cheese

B-3.02 -- Functions of Proteins in Food
84
85
Produce Foams

• A foam is a gas suspended in a liquid or
  semi-solid.
• Foams made by
• Bubbling gas through a mixture
• Foaming milk for a cappuccino
• Whipping or beating
• Beating egg whites with a mixer
• Depressurization
• Whipped cream in a can
• Soft drinks

B-3.02 -- Functions of Proteins in Food
85
86
Develops Gluten

• Gluten is a strong cohesive and elastic protein.
• Developed in baked products, such as bread
• Less developed in pie crusts, quick bread,
  muffins, biscuits, cakes, cookies
• To prevent gluten development
• Add other grains such as rye and corn
• Add more sugar
• Add more liquid

B-3.02 -- Functions of Proteins in Food
86
87
(No Transcript)
88
Vitamins and Minerals
89
Vitamins

• Organic compounds
• Do not provide energy
• Need small amounts
• Classified as
• Fat-soluble
• Water-soluble

B-3.02 -- Vitamins and Minerals
89
90
Fat-soluble Vitamins

• Found in fats and oils in food
• Fairly heat-stable, water stable
• Vitamins, A, D, E, K

B-3.02 -- Vitamins and Minerals
90
91
Vitamin A

• Retinol -- active form
• Yellow color
• Animal sources -- butter, liver, egg yolks
• Beta-carotene -- inactive form
• Bright orange vegetables
• Plant sources -- carrots, sweet potatoes
• Dark green vegetables

92
Vitamin D

• Few foods naturally contain vitamin D
• Butter, cream, egg yolks, liver
• Milk is fortified with vitamin D
• Can be obtained from sunlight

B-3.02 -- Vitamins and Minerals
92
93
Vitamin E

• Functions as an antioxidant in foods
• Whole gains, nuts, seeds, oils
• Not stable at high temperatures

B-3.02 -- Vitamins and Minerals
94
Vitamin K

• Blood clotting
• 1/2 provided by bacteria in intestines
• 1/2 from dark green leafy vegetables

B-3.02 -- Vitamins and Minerals
94
95
Water-soluble Vitamins

• Water-soluble
• Sensitive to
• Prolonged heating
• Water exposure
• Riboflavin to light
• B-complex group and Vitamin C

B-3.02 -- Vitamins and Minerals
95
96
B-Complex Group

• Thiamin
• Riboflavin
• Niacin
• Pyridoxine
• Cobalamin
• Folate
• Pantothenic acid

B-3.02 -- Vitamins and Minerals
96
97
B-Complex Group

• Many foods enriched with
• thiamin, riboflavin, niacin, considering folate
• Vegetarian foods
• fortified with cobalamin (B12)

98
B-complex vitamins

• Found in
• whole grains, molasses, meats, poultry, brewers
  yeast, egg yolks, vegetables (especially green
  leafy), beans, rice, baked goods

99
Vitamin C

• Ascorbic acid
• Damaged by prolonged heat, water exposure
• Functions
• Form collagen, help absorb iron
• Antioxidant -- easily oxidized
• Found in
• Fresh fruits, vegetables

B-3.02 -- Vitamins and Minerals
99
100
Minerals

• Simplest chemical structure
• Minerals are elements
• Categorized based on need
• Major minerals
• 100 mg. or more each day
• Calcium, phosphorus, sodium, potassium, chloride,
  magnesium, sulfur
• Trace minerals
• Less than 100 mg. each day
• Iron, zinc, fluoride

B-3.02 -- Vitamins and Minerals
100
101
Calcium and Phosphorus

• Calcium
• Found in
• Dairy products, such as milk
• Fortified foods, such as orange juice, soy milk
• Phosphorus
• Found in many foods
• Soft drinks

B-3.02 -- Vitamins and Minerals
101
102
Sodium, Chloride, Potassium

• Functions and Food Sources
• Sodium and chloride table salt
• Fluid balance
• Adds flavor to foods
• Most sodium in our diet comes from salt
• Potassium found in all fresh foods
• Potassium chloride -- Salt substitute

B-3.02 -- Vitamins and Minerals
102
103
Iron

• Function
• Red blood cell formation
• Iron-deficiency anemia
• Major concern with women and teens
• Fortified in foods
• Found in
• Meats, organ meats, green leafy vegetables,
  fortified foods
• Vitamin C helps absorb iron

B-3.02 -- Vitamins and Minerals
103
104
Iodine and Zinc

• Iodine
• Regulated bodys use of energy
• Found in
• Seafood
• Fortified in salt
• Zinc
• Wound healing
• Immune function
• Dietary deficiency concerns among teens
• Found in
• Meat, fish, poultry

B-3.02 -- Vitamins and Minerals
104
105
Fluoride

• Healthy bones and teeth
• Found in
• Toothpaste
• Drinking water (added)

B-3.02 -- Vitamins and Minerals
105
106
(No Transcript)
107
Functions of Vitamins and Minerals in Food
108
Functions

• Vitamins and minerals have two major functions in
  food
• Enrichment
• Fortification
• Classified as an intentional food additive so
  regulated by USDA or FDA.

B-3.02-Functions of Vitamins and Minerals
108
109
Enrichment

• Restoring some of the nutrients removed from
  refined grain products during processing
• Removal of bran layer from wheat to make refined
  wheat flour
• Polished rice
• Addition of thiamin, riboflavin, niacin to
  refined grain

B-3.02 -- Functions of Vitamins and Minerals
109
110
Fortification

• Adding nutrients to a food because of nutritional
  deficiency concerns
• Nutrient is not generally present naturally in
  the food being fortified
• Fortificant and food vehicle
• Bioavailability of nutrient
• Iron and vitamin C in orange juice
• Examples
• B-12 in soymilk
• Vitamin D in milk
• Iron in orange juice

B-3.02-Functions of Vitamins and Minerals
110
111
Food Additive

• Increases the vitamin and mineral content of a
  food
• Added for non-nutritive reasons
• Preserve foods
• Stabilize foods
• Examples
• Calcium salts in tofu, canned vegetables
• Sodium chloride (salt) in canned foods
• Ascorbic acid for fresh cut fruits

B-3.02-Functions of Vitamins and Minerals
111
112
Processing and Vitamins and Minerals
113
Effects of Processing on Vitamins and Minerals

• Effects depend on the sensitivity of the vitamin
  or mineral to
• heat
• oxygen
• pH
• light
• Vitamin content more likely to be affected by
  processing than is mineral content.

B-3.02 -- Processing and Vitamins and Minerals
113
114
Specific Effects of Processing

• Vitamin C (ascorbic acid)
• Decrease during storage, drying, heating,
  oxidation, and chopping/slicing
• Stable to heat under acidic conditions
• Vitamin B1 (thiamine)
• Destroyed by high temperature, neutral and
  alkaline conditions
• Lost in cooking water
• Vitamin B2 (riboflavin)
• Sensitive to light at neutral and alkaline
  conditions
• Moderately heat stable under neutral conditions
• Sensitive to heat under alkaline conditions

B-3.02 -- Processing and Vitamins and Minerals
114
115
Specific Effects of Processing

• Vitamin B3 (niacin)
• Most stable vitamin
• Stable to heat and light
• Leaches in cooking water
• Folate
• Decreases with storage and prolonged heating
• Lost in cooking water
• Destroyed by using copper utensils
• Vitamin B6 (pyridoxine)
• Heat stable in alkaline and acidic conditions
• Vitamin B12
• Destroyed by light and high pH

116
Specific Effects of Processing

• Carotenes
• Easily destroyed by heat
• Destroyed when exposed to heat and light
• Vitamin A
• Easily destroyed by heat
• Vitamins D and E
• Oxidize when exposed to heat and light

117
Additives

• Perform useful functions in foods.
• Vitamins and minerals added to many foods, to
  make up for those lacking in a person's diet or
  lost in processing.
• Such fortification and enrichment has helped
  reduce malnutrition among the U.S. population.
• All products containing added nutrients must be
  appropriately labeled.

B-3.02 -- Processing and Vitamins and Minerals
118
Enrichment

• Adding one or more nutrients already present in a
  food in lower than desirable amounts.
• Examples include
• Bread -- enriched with B vitamins lost in the
  processing of white flour.
• Enriched flour -- pasta, tortillas, and any
  products made with enriched white flour are also
  enriched foods.

B-3.02 -- Processing and Vitamins and Minerals
119
Fortification

• Adding significant quantities of a nutrient not
  originally present in a food or present only in
  nutritionally insignificant amount.
• Examples include
• Low fat and non-fat milk -- fortified with
  vitamin A
• Orange juice fortified with calcium
• Salt -- fortified with iodine
• Milk -- fortified with vitamin D
• Cereals and fruit juices often fortified with
  vitamins and minerals

B-3.02 -- Processing and Vitamins and Minerals