Food Science - Exam #2 Flashcards
1
Q
What are foods made of?
A
Matter;
-Which is composed of pure substances, as either elements or compounds
2
Q
What are Elements?
A
The simplest form of matter - cannot be broken down further. (without physically changing them)
3
Q
What are Compounds?
A
- Made of two or more elements chemically bonded in definite proportions by weight, to make a new material
- Basically makes up everything;
- Represented as formulas of elemental composition
4
Q
What are the important compounds to food science?
A
- Organic compounds.
- All contain Carbon (C), Hydrogen (H), oxygen (O) and sometimes sulfur(S), nitrogen (N) or phosphorus (P)
5
Q
What are Mixtures?
A
- Two or more substances are combined physically.
- Solutions, dispersions, emulsions**
6
Q
What are Chemical Symbols?
A
one or two letter designations for elements depicted in the periodic table
7
Q
What are Chemical Formulas?
A
depicts all of the elements in a compound, including proportions as subscribed numbers
8
Q
What are Chemical Equations?
A
–A written description of a chemical reaction using chemical symbols and formulas.
-C6H12O6 + 6 O2 → 6 CO2 + 6 H20 (breakdown of glucose)
9
Q
What happens in a chemical reaction?
A
- Atoms/molecules interact with each other through chemical bonding.
- Results in a new substance with different properties from the reactants
10
Q
How do elements interact through CHEMICAL BONDS?
A
- Requires energy.
- Only ELECTRONS are involved in chemical bonds
11
Q
How are protons and neutrons treated in compounds?
A
- Protons and neutrons are NOT involved.
- Protons only account for the mass of the chemical
12
Q
How are electrons treated in compounds?
A
- Electrons are negatively charged and are attracted to positively charged nucleus.
- Atom can be seen as having a series of electron orbits.
13
Q
How is the MAX number of electrons in each orbit determined?
A
-Use X=2n^2. •1st level – 2 •2nd level – 8 •3rd level – 18 •4th level –32
14
Q
What is the Valence Electron Shell?
A
- OUTERMOST electron shell;
- Most atoms become chemically stable when they have 8 electrons in their outermost shell
15
Q
What is the chemical formula for Propionic Acid?
A
C3H6O2
16
Q
What do structural formulas show?
A
-Help visualize how the bonding takes place
17
Q
What are Covalent Bonds?
A
- Occur when electrons are shared;
- One, two or three pairs of elections can be shared resulting in single, double, or triple bonds
18
Q
What are the bonds in fats, proteins, carbs, and vitamins?
A
- Covalently bonded carbon atoms.
- Form the backbone of these molecules
- You can have 1 -3 bonds shared.
- The more bonds shared, the more energy stored.
19
Q
What are Ionic Bonds?
A
- TRANSFER of elections between reactants.
- Resulting in a FULL valence shell of both elements;
- EX: Salt (NaCl) - most important bond in food science because we always use salt
20
Q
What are Cations?
A
- Elements that donate electrons become positively charged in an ionic bond;
- EX: Sodium (Na+)
21
Q
What Anions?
A
- Elements that receive electrons are negatively charged in an ionic bond;
- EX: Chlorine (Cl-)
22
Q
What are Hydrogen Bonds?
A
- A type of covalent bond with unequal rather than equal sharing of electrons, resulting in a weak force;
- Type of intermolecular bond
23
Q
What are Intermolecular Bonds?
A
-Bonds between two different MOLECULES.
24
Q
When do hydrogen bonds occur?
A
- Occur when elements such as oxygen and nitrogen in one compound come into close proximity with hydrogen from another compound and share the electron of hydrogen;
- How was orients itself
25
What are the chemical reactions in foods?
- Composition reaction;
| - Decomposition reaction
26
What are Composition Reactions?
- Two or more substances combine resulting in a single product (A+B = AB).
- EX: Synthesis of protein from amino acids
27
What are Decomposition Reactions?
- One substance becomes two products (AB à A+B).
| - EX: Hydrolysis of maltose yields two glucose molecules
28
Enzymatic vs. Non-enzymatic
- Either reaction type may be either enzymatic or nonenzymatic.
- Nonenzymatic- don't require enzymes, just happens
29
What are Enzymes?
- Specialized proteins and serve as biological catalysts (cause reactions to speed up) of chemical reactions;
- Positive effect = tenderization of meat;
- Negative effect = browning of cut fruits and veggies
30
What is an Active Sites in an enzymatic reaction?
- Location where the substrate joins with the enzyme to form the enzyme substrate complex;
- Three dimensional region that contains amino acids that bind, non-covalently, to the substrate.
31
What scientists worked out the enzymatic reactions?
- The biochemists Michaelis and Menten worked out the kinetics of enzymatic reactions.
- E + S ←→ ES ←→E +P
32
What is Activation Energy?
- The amount of energy required for a reaction to take place.
- Enzymes reduce the activation energy thus speeding up the reaction.
33
What is Enzymatic Hydrolysis?
- Breakdown of large components into smaller ones
| - Ex: carbohydrases, lipases, proteases (protein hydrolysis)
34
What is Enzymatic Oxidation-Reduction?
- Oxidation is the loss of electrons and reduction is the addition of electrons.
- Ex: the browning of fruits and vegetables via polyphenol oxidase.
- In nature, they are coupled.
- OIL-RIG
- Occurs everywhere.
35
What is Enzymatic Polymerization?
- Occur through CONDENSATION reaction;
- The joining of two compounds
- When many condensations occur within the same molecule, a POLYMER is formed.
- Water is released.
- Small molecules join to form long chain
- Happens a lot in protein and fats
36
What are Nonenzymatic Reactions?
```
-Reactions occur in nature in the absence of an enzyme catalyst;
Types include =
•Addition
•Oxidation-reduction
•Hydrolysis: adding water
•Condensation: removing water
```
37
What are Addition Reactions?
-The addition of an element to a compound.
EX: Hydrogenation of unsaturated fatty acids where hydrogen is added to the double bonds.
EX: Margarine
38
What are Oxidation Reduction Reactions?
-Electrons are transferred between substances;
-Can affect color, quality, acceptability of foods.
•Oxidation – the ADDITION of oxygen
•Reduction – the GAIN of hydrogen
Can be caused by UV light, heat, high oxygen environment, metal catalyst, etc.
39
What are Condensation and Hydrolysis Reactions?
- Complimentary reactions;
| - Generally catalyzed by heat or acid
40
What are Condensation Reactions?
-When two molecules are joined together with the formation of a new product and water.
41
What are Hydrolysis Reactions?
-When a molecule is broken apart in the presence of water, which is incorporated into the two new products
42
What are Functional Groups?
- Arrangements of atoms that create certain properties of molecules;
- Component molecules play an important role in functionality of the food itself.
43
Alcohol Group
- OH or hydroxyl;
| - Important food alcohols include ethanol and glycerol.
44
Aldehyde Group
- Carbon at the end of the molecule which is double bonded to oxygen.
- Important in odors and flavor of foods
45
Amino Group
- Contains an amino (-NH2) functional group.
| - Histamine, serotonin and dopamine are amines
46
Carboxylic Acid Group
- Carbon on the end of a molecule bonded to a hydroxyl and double bonded to an oxygen.
- Ex: citric acid, acetic acid (vinegar).
47
Ester Group
- Carbon double bonded to an oxygen and single bonded to a second oxygen which is bonded to another carbon.
- Associated with characteristic aroma of foods
48
Ketone Group
- Interior carbon atom is double bonded to an oxygen.
| - Associated with flavor of food (cooking of meats, brewing of beer
49
Methyl Group
- Carbon bonded to three hydrogen. (CH3)
- One of the important building blocks of organic molecules;
- Found in pectins and gums
50
Phosphate Group
- Phosphorus bonded to two hydroxyls and double bonded to one oxygen and single bonded to one oxygen. (-PO4)
- Added to meat to improve texture, juiciness and water-holding capacity.
- High source of Energy (ATP)
51
Sulfyhydryl Group
-Sulfur bonded to a hydrogen (R-SH)
-Compounds containing sulfhydryl groups are called THIOLS;
-Important to structure of foods (e.g. in bread dough);
-Both bad and good
Ex: smell of rotten eggs
Ex: popcorn and baked bread
52
What are Functional Properties?
-The chemical and physical factors that impact the behavior of food during formulation, processing and storage
53
Why is the functionality of water so important?
- Because most food contains a large proportion of water, its functionality is a highly critical factor relative to the quality of food.
- Helps determine: shelf life, taste, texture.
54
What are functions attributed to water?
- Diluent and carrier of hydrophilic components = Things that can dissolve in water
- Medium for chemical reactions = Provides a place for things to float around in.
- Solvent
- Medium of heat transfer (And freeze)
- Participates in chemical reactions = Due to it’s negative and positive sides
55
What is the molecular structure of water?
- Two hydrogens bonded to one oxygen;
- Each H shares an electron pair with the O (pulls more);
- DIPOLE created with Oxygen more negative and Hydrogen more positive (Magnet)
56
What does the Hydrogen Bonding of water result in?
- High boiling point and freezing point
- High vapor pressure
- High interfacial tension (spider walking on water)
57
What is Solubility?
- Ability to be dispersed into solution;
| - Hydrophilic compounds disperse readily in water
58
What is Hydration?
- Water molecules contact and surround polar molecules by acting as a solvent.
- Polar molecules
59
What are Amphiphilic Molecules?
-Contain BOTH polar and nonpolar regions.
-When water interacts with these compounds, micelles are formed.
Ex: proteins, phospholipids, sterols, and soap.
(Soap and dissolve water on one side and oil on the other)
60
What is Moisture?
- Amount of water in a food.
- Because of bacteria
- Determines your shelf life and risk for contamination.
- A lot of water can cause reactions to occur and change the product
61
What is Water Activity?
- Amount of water available for chemical reactions or to support microbial growth, enzymatic/chemical reaction;
- Free, Structural, or Bound water in foods
62
What is Free Water?
Participates in chemical reactions and support microbial growth
63
What is Structural Water?
Participates in chemical reactions and support microbial growth
64
What is Bound Water?
- Tightly associated with food components and does NOT act as typical water molecules do.
- Not available for reactions or microbial growth.
- When you have salt and sugars (which is attractions water), all of the sugar and salt will bind to the water (Making a jam)
65
What is an Emulsion?
- Colloidal dispersion in which two normally immiscible fluids are mixed.
- Has a continuous phase into which a dispersed phase is mixed
66
What are Emulsifiers?
- Amphiphilic compound;
- Generally needed to establish and stabilize EMULSIONS.
- Soaps and fats.
- One polar side and nonpolar side.
- Pic= oil droplet are SMOOTH in the pic, means suspended in water.
- Protein pic=the arm is water soluble, and the other isn’t; “theyre holding hands”
67
How is water involved in Heat Transfer?
-Acts as a conductor of thermal energy to foods (AKA heat transfer)
68
What must be done to water in foods, especially frozen?
Must be stabilized
69
What are the food acids?
-Food acids come in a variety of forms including amino acids, fatty acids, fruit acids such as acetic and citric acids, etc;
-The acid donates a proton to the water molecule and form charges.
oLost proton= negative charge
oGain proton= positive charge
70
What is the structure of food acids?
- Primarily carboxylic acid based (i.e. organic acids).
- Differences in size, number of carboxylic units and location of carboxylic acid within the molecular structure, all influence the characteristics of the acids
71
What are Acids?
- Donate (or lose) protons
| - Acid strength is dependent on its ability to dissociate.
72
Strong vs. Weak Acids
-Weak acid– a small amount of H ions have separated.
(Foods are usually weak acids)
-Strong acid– have large amounts of dissociated ions
73
What are food acids considered?
- All food acids are considered weak acids because of a small dissociation, or IONIZATION CONSTANT;
- Determines how strong an acid is in a food product
74
What is Fumaric Acid?
-Can soften bread doughs by breaking disulfide bonds between cysteine molecules.;
-Flour proteins contain amino acid CYSTEINE.
•**know that it contains –SH.
75
What is a Salt?
-A hydrogen atom in the carboxyl group is replaced by a metal ion (charged) such as Na, Ca, or K;
-In water, the Na and Cl separate to form ions;
-When they bind with something else, it still makes a salt.
EX: -COOH + ion = salt
76
What are Buffers?
- A system of a weak acid and a salt of the acid in which the pH is maintained;
- “regulators”;
- Can be used for different levels of pH.
77
How do buffers regulate pH in foods?
- Keep the pH stable in the reaction by accepting and donating proton;
- Most foods need to be buffered to below 4 to have a good shelf life
78
What is Leavening?
- Production of gas by either yeast fermentation, the reaction of an acid with baking soda, or by heating of salts.
- Natural = Anaerobic respiration of yeast
79
What is Chemical Leavening?
- Requires an acid (leavening acid) and a carbonate, usually sodium bicarbonate.
- The acid releases the CO2 from the carbonate in a multi-step process;
- React with acids to produce CO2, causing dough to rise without yeast.;
- Baking soda- reacts with acid immediately
- Baking powder-double acting
80
What is Baking Powder?
- Complete leavening system;
- Mixture of cream of tartar and baking soda.
- Has two reactions at different temp: one to raise the bread and another to stop it.
- “DOUBLE ACTING” = increases the quality in the bread
81
What is pH?
- The dissociated hydrogen ion concentration on a logarithmic scale according to the equation;
- pH=- log of hydrogen ion concentration [H+];
- Range from 1-14;
- LOW pH (acidic) can prevent microbial growth and spoilage
82
What is Titratable Acidity?
- Another indication (dyes) of a food’s acidity;
- Measure of dissociated and non-dissociated H;
- Critical quality control tool in many food products.
- Ex) fermented products (i.g. beer, peppers, sour kraut) you use the titrability of acidity to see if you've reach the acidity level in your product. Figures out quality
83
How is Titratable Acidity measured?
-By titration with a known concentration of base to a predetermined pH.
84
What are Acid Foods?
-Possessing a natural pH of less than 4.6
85
What are Low Acid Foods?
- Possessing a natural pH greater than 4.6.
| - Our limit for few microbials to grow
86
What are Acidified Foods?
- A low acid food to which an acid is added such that the resulting pH is less than 4.6.
- Ex) Adding vinegar.
87
What are Fermented Foods?
-Low acid foods that undergo natural fermentation that results in the reduction of pH
88
What is the structure of Sugars?
- Carbon, hydrogen and oxygen.
- Simple sugars = Monosaccharides, Disaccharides;
- Structural features, which are dependent on the location of FUCNTIONAL GROUPS, have an influence on functional properties;
- Simple sugars can be syrups or crystals in food
89
What are Sugar Alcohols?
- Sugars with modification of one corner of their molecule = –OH group that binds to the reducing end of a monosaccharide unit making the sugar NONREDUCING;
- Cause slow rise in blood insulin levels.
- Do NOT participate in BROWNING reactions
- Lacking ALDEHYDE group
- NOT good for cooking, no browning!;
- "ol"= sugar alcohol ingredient
90
What are the Monosaccharides?
-Trioses - 3 carbons.
-Pentoses – 5 carbons.
-Hexoses – 6 carbons.
= Glucose, fructose, galactose – C6H12O6
91
What is the difference between Glucose and Fructose?
-Glucose has a SIX member ring (aldose)
-Fructose has a FIVE member ring (ketose)
= This difference is partially responsible for the fact that fructose is sweeter and more soluble than glucose.
-Fructose is the KETOSE version of Glucose (ALDOSE)
92
What are the Disaccharides?
- Two monosaccharides bonded together by a glycosidic bond;
- Sucrose – glucose + fructose) - common table sugar;
- Lactose – glucose + galactose) - milk sugar;
- Maltose – glucose + glucose) - common breakdown product from starch
93
What is the Alcohol (-OH) functional group important for?
Solubility and sweetness
94
What is the Carbonyl (C=O) functional group important for?
- Reducing activity and MAILLARD browning for color/flavor development;
- Functional group artificial sweeteners DON’T express
95
What are Reducing Sugars?
- Contain a CARBONYL group (aldehyde or ketone)
- ALL monosaccharides are reducing sugars.
- Gives the ability to form disaccharides and polysaccharides by allowing bonding between monosaccharides;
- Reative -OH group at C1 (aldehydes) or C2 (ketones) in cyclic structure
96
What are the browning reactions that occur in sugars?
- Maillard Reactions
- Caramelization Reactions
- Both are categorized as NONENZYMATIC
97
What is the Maillard Reaction?
- Complex series of reactions that requires a REDUCING SUGAR and AMINO ACID in foods and results in Browning of sugars;
- Intermediate products: pyrazines which tend to have pleasant aromas and flavor;
- End products: brown pigments called melanoids;
- IRREVERSIBLE and result in darkening of food
98
What are the conditions for the Maillard Reaction?
- Takes place at relatively low temperatures and can be accelerated by lower molecular weight sugars, low moisture content (<15%) and in the pH range of 5-8.;
- Condensations, Rearrangement, Polymerization
99
What is Caramelization?
- Takes place at high temperature (200C);
- Only occurs at high temps, but very easily burns;
- Due to the DEHYDRATION of the sugar molecule;
- BREAKS DOWN the sugar by the use of heat and forms crystals
100
What is the difference in Caramel Coloring and Caramel?
- Caramel coloring = refers to a brown coloring used in the food industry.
- Caramel = refers to sauces or candies made from carbohydrates that have been allowed to caramelize
101
What is Crystallization?
- Implies organized 3-D arrays of unit cells into solid form;
- As the sugars cool, the solids reforms in crystalline structures
- In candy manufacture, control of the crystallization process is highly critical to the ultimate quality of the candy
102
What is a Humectant?
- Substance that has an affinity for moisture, also referred to as HYGROSPOPIC substances;
- Hygroscopic – substance that ATTRACTS water;
- This is ultimately related to their ability to form bonds with WATER
103
What is Inversion?
- Process where sucrose is hydrolyzed to fructose and glucose, which are then called Invert Sugars;
- Can be done by heat, acids, specific enzymes;
- Inversion can be induced by heat, acid, or a special enzymes called INVERTASE
104
What are the effects of Oxidation Reduction reactions?
- Promote important functional characteristics of sugars;
- Oxidation of the ALDEHYDE group in sugars causes a LOSS of sweetness and converts it to an acid;
- Reduction of the carbonyl group of reducing sugars causes the formation of SUGAR ALCOHOLS, which are moderately sweet.
- Ex: mannitol and sorbitol
105
How are sugars ranked by sweetness?
- SUCROSE is usually used as the reference with other sugars;
- Fructose > sucrose > glucose > maltose > galactose > lactose
106
What effects do sugars have on the textures of foods?
- Effect on texture through their interaction with water.
- Sugar can provide bulk, tenderization (e.g. in baked goods) and can influence other texture promoting compounds such as starch;
- Sugar is HYGROSCOPIC – ultimately affects texture
- Hydrogen bonds are formed between water and sugar
107
What happens to Sugar when heated in the presence of an acid?
- Breaks down into glucose and fructose resulting in an invert sugar
- Invert sugars are viscous liquids and very hygroscopic
- Brown sugars are coated with molasses and therefore have more invert sugar
108
What are the Complex Carbs?
- Oligosaccharides (3-10 units);
| - Polysaccharides (>10 units)
109
What are the Oligosaccharides?
EX: Raffinose and Stachyose;
- Present in dried beans. → “-ose” means sugar
- NOT digested in the small intestine but are fermented by microorganisms in the large intestine.
110
What Polysaccharides?
- Much more abundant in foods than oligosaccharides;
| - Commonly used as additives to food for specific aspects of functionality
111
What are Beta-Glucans?
-Polymers of glucose;
-SOLUBLE dietary fibe;
-Been found to lower serum cholesterol;
-Primarily in OATS, along with BARLEY and YEAST,
-Fat replacer in many different manufactured food products.
= Oatrim – used in baked goods, fillings and frostings, frozen desserts, salad dressings, etc.
112
What is Cellulose?
- Plant polysaccharide of glucose;
- Structural component of all plant cell walls;
- Main source of INSOLUBLE dietary fiber;
- We don’t possess the enzymes to digest
- Microparticulate form of cellulose is used as a bulking agent and to increase dietary fiber in foods
113
Where do Dextrin and Maltodextrin come from?
Breakdown of starch;
- Dextrin = any start undergone heat degradation, usually with heat;
- Maltodextrin = specifically related to commercially generated products, usually cornstarch (Used in sauces, baking, processed meat as fat replacer) and bulking agent
114
What are Fructooligosaccharides?
- Polymers of FRUCTOSE usually with sucrose;
- Variety of plants like garlic, onions, bananas;
- PREBIOTICS because they are not broken down in the small intestine and make it to the large intestine where they nourish good bacteria (probiotics)
- Prebiotics → feed the probiotics
- Probiotics → Good bacteria the utilize prebiotics
115
What is Inulin?
- Type of fructooligosaccharide found in onions, asparagus and especially chicory root.
- Serves as a prebiotic to stimulate the growth of good bacteria.
- Can be used to adjust textural attributes
116
What are Pectic Substances?
- High molecular weight polysaccharides found in plant cell walls, primarily for support. ;
- Composed of galacturonic acid units some of which are METHYLATED, which determines functionality;
- Protopectin;
- Pectinic Acid;
- Pectic Acid
117
What is Protopectin?
-Nonmethylated and found in immature fruit → NO GEL
118
What is Pectinic Acid?
-Methylated and produced during ripening → GELS
119
What is Pectic Acid?
Demethylated derivative of pectinic acid and associated with overripe fruit → NO GEL
120
What is Degree of Esterification?
- Methoxylation = deterimines functionality of pectins;
| - High methoxyl (HM) pectin have > 50% methylation, whereas low methoxyl (LM) pectin generally has < 30% methylation.
121
What is Pectin Gelation?
Pectins are able to form colloidal dispersions (sols and gels) =
- To convert a HM pectin sol to a gel it is necessary to reduce the association of pectin with water by incorporating sugar and reduce the repulsive forces between pectin molecules.
- LM pectin can be converted into a gel without sugar by adding divalent CATIONS such as calcium (makes sugar free jelly)
122
What is Starch?
- Predominate source of dietary energy in the world’s food supply;
- Packaged in plants as starch granules;
- Can be modified to change functionality (pre gelatinized)
- Polymer of glucose molecules, found in two forms =
- Amylose – a straight chain;
- Amylopectin - numerous branches; lots of reducing ends so can form a lot of bonds
123
What is starch gelatinization?
- NOT soluble in cold water, but if agitated and heated it undergoes a conversion that is referred to as gelatinization;
- The heated starch granules absorb water and swell.
- Irreversible reaction.
- Increased viscosity
124
What is Starch Paste?
- A starch/water system the has both thick liquid and solid-like properties.
- In a paste, majority of starch granules have gelatinized, producing swollen and disrupted granules;
- Pasting = continuation of gelatinization where thickening of a slurry occurs
125
What is Gelation?
- The formation of a gel from a cooled paste.;
| - Starch gel – a thick starch/water mixture that has properties of a solid.
126
What is Starch Retrogradation?
- Contraction of starch gels due to interactions between amylose molecules;
- As the gel tightens it can loose water, which is referred to as SYNERSIS
127
What is the starch content of potatoes?
16-22% starch
128
What are Vegetable Gums?
- Broad category of complex polysaccharides that contain a variety of sugars including pentoses and hexoses;
- Can be used to add texture to foods without altering caloric content;
- Gums are derived from a variety of sources including plant seeds (guar) seaweed (carageenans) and microorganisms (xanthan)
129
What is the chemical structure of fats lipids?
- Triglyceride;
- Glycerol backbone (3-C alcohol) with 3 fatty acids chains attached;
- Fatty acids contain a carboxyl end and a methyl end
130
How are fatty acids named?
- Saturated – does not contain any C=C;
- Unsaturated – have one or more C=C;
- OMEGA naming system names fatty acids by where the first double bond occurs counting from the METHYL group backward
131
What are conjugated double bonds?
When the double bonds occur between every other carbon
132
What are methylene interrupted double bonds?
- When a carbon without a double bond occurs between two sets of double bonds;
- More typical and more reactive.
133
What are CIS and TRANS fats?
- Refers to geometric configuration around the double bond of unsaturated FA;
- Hydrogen are on the SAME it is cis;
- Hydrogen are on OPPOSITE sides it is trans (Usually from modification)
- Trans is unsaturated that looks like saturated;
- CIS is more common in regular fats, but trans configuration occurs when vegetable oil is hydrogenated
134
What is Melting Point?
- Temp where a solid is converted to a liquid.(AKA freezing point);
- Fats = solid at room temperature are referred possess crystalline structure;
- The composition of the fat affects its melting point;
- More SIMILAR the triglycerides in a given fat the NARROWER the melting range;
- LONGER chain fatty acids have HIGHER melting points than SHORTER chain;
- Saturated higher than unsaturated, trans higher than cis;
* *More energy contained in longer bonds, so requires more heat to break
135
What is Smoke Point of lipids?
- Characteristic temperature at which fats begin to BREAK DOWN;
- Most fats begin to DECOMPOSE before their boiling point;
- May spontaneously ignite on the stove if their fumes come in contact with flame.;
- Depends on initial free fatty acid content.
136
What are flavor compounds of lipids?
- Essential Oils
| - Lipid degradation products
137
What are Polar Lipids?
-Represented primarily by phospholipids, these lipids have BOTH polar and nonpolar regions – AMPHIPHILIC
138
How are lipids used for pigments?
Many of the pigments that provide color to plants and animals are fat soluble
139
What are Waxes?
- High melting point lipids composed of a long chain fatty acid and a long chain fatty alcohol, esterified to each other;
- They primarily occur in the OUTER layer plants and provide protection.
140
What is Fractionation of fats?
- Splits lipids into higher and lower melting point component parts;
- Can produce a good frying oil and plastic fat for shortening from same starting material;
- Plastic fat – chemical term for long chains
141
What is Hydrogenation of fats?
- The forced addition of hydrogen to unsaturated lipids;
- Put the fat in a situation where it wants to break its double bonds and add Hydrogens;
- Raises the melting point and increase stability;
- Produces trans fatty acids, which may have health disadvantages.
142
What is Hydrolysis?
-Reaction requiring heat plus the addition of water molecules to separate fatty acids from glycerol;
Produces an off flavor referred to as HYDROLYTIC RANCIDITY (release of short chain fatty acids);
143
What is ACROLEIN from the hydrolysis of fatty acids?
-When all three fatty acids are lost during heating the glycerol molecule can be further degraded to acrolein, which is responsible for the noxious aroma of oils that are at their smoke point.
144
What is Interestification of fats?
- Rearrangement of fatty acids on the glycerol molecule to create less homogenous triglycerides molecules;
- The primary function is to cause plastic fats such as lard to have a smoother texture.
145
What is Oxidation of fats?
- Oxygen reacts at the double bonds of unsaturated fatty acids and causes the production of small organic compounds that are responsible for “rancid” odors;
- Reaction sequence can be caused by heat, light, metals, oxygen, etc;
- ANTIOXIDANTS can prevent the reaction by donating hydrogen which basically terminates the reaction.
146
What is created when Unsaturated FA's react with oxygen?
-HYDROPEROXIDES and eventually the degradation of the peroxide to volatile compounds (ketones, aldehydes, alcohols, acids).
147
What is Polymerization of Fats?
- Primarily occurs in heated oils where fatty acids that are cleaved from the glycerol molecules link together to produce polymers.;
- Contribute to the smoking of overheated oil and the darkening of foods cooked in overheated oils.
148
What are the functions of Fats?
- Aeration
- Crystallization
- Emulsification
- Flavor
- Heat Transfer
- Mouthfeel
- Plasticity
- Tenderization
149
What is Aeration of fats?
-“creaming the fat” when baking cakes;
-Incorporates air through agitation of a batter which is held in place by the crystal molecule arrangement of the fat;
Ultimately responsible for the crumb, or texture of many baked products
150
What is Crystallization of fats?
-All food fats contain very small crystals of fat which are composed of the fat’s triglycerides
151
What is Polymorphism?
- Different crystalline arrangements of triglycerides;
- Include the classifications α, β, β-prime =
- BETA-PRIME is the most desirable from a functionality standpoint because they provide a smooth texture.
- BETA CRYSTALS are coarser.
- More HOMOGENOUS triglycerides result in β crystals;
- Fats are interesterified to reduce the homogeneity and produce β-prime crystals;
- The more homogeneous the more narrow the melting range
152
What is Emulsification of fats?
- Lipids are an important component of all food emulsions;
| - Ex: Cake Batter – Oil in water emulsion
153
What is Flavor related of fats?
- Lipids are believed to have the greatest impact on flavor;
- Iinherent flavor properties;
- Carry flavor compounds that are lipid soluble such as TERPENOIDS;
- Terpg many other flavors, which are contained in what is referred to as essential oils
154
What are Terpenoids?
-Terpenoids are responsible for citrus flavor, among many other flavors, which are contained in what is referred to as essential oils
155
Why are fats good for frying?
- Lipids can be heated to HIGHER temperature than water;
- Around 325-375F ;
- Dry-heat cooking;
- Creates crisp crust, more flavor;
- Prevents greasy taste
- Can get too hot
- CANNOT re-use oil indefinitely
156
What is the mouthfeel of fats?
Smooth, creamy sensation during the mastication of food
157
What is the Plasticity of fats?
- Physical property of a fat which describes its softness at room temperature;
- Plastic fat will deform when spread but hold its new shape;
- Due to the CRYSTALLINE NATURE of solid lipids.
- β-prime crystals have a smoother texture, which can be achieved by proper tempering;
- Fats composed mainly of β crystals are less plastic and more grainy to the touch.
158
What is Tenderization of fats?
- Lubrication properties of lipids, they also promote tenderization of foods that contain them;
- Meat that has HIGHER fat content (marbling) is MORE TENDER than meat that has less intramuscular fat;
- In baked goods, lipid interferes with gluten formation
159
What are proteins composed of?
- Polymers (polypeptides) of amino acids linked with peptide bonds;
- Connects the amino group of one amino acid to the carboxylic acid group of another amino acid
160
What are amino acids made of?
- An amino group;
- A carboxylic group;
- A functional group = Functional group dictates classification as neutral, basic, acidic, aromatic or sulfur containing amino acids
161
What are non conjugated proteins?
Contain only amino acids
162
What are conjugated proteins?
- Combined with other nonprotein substances. → Most of the protein in FOODS!!;
- Carbohydrate: glycoproteins, e.g. egg white
- Lipid: lipoproteins, e.g. egg yolk
- Metals: metalloproteins, e.g. hemoglobin
- Phosphorus: phosphoproteins,
163
What are the levels of protein structures?
-Primary = linear arrangement of amino acids
(N-C-C-N-C-C (shorthand for primary structure);
-Secondary = structural arrangement of the amino acids such as alpha-helix, beta-pleated sheet;
-Tertiary = overall three dimensional structure;
-Quarternary = arrangement of more than one peptide chain within a single protein molecule
164
What is buffering of proteins?
- Preventing a pH change by undergoing an ionization reaction;
- Amphoteric – can behave as both acids and bases.
- Carboxyl groups can act as ACIDS
- Amino groups can act as BASES
* Proteins can serve as buffers (maintain pH) because of this and can be either acidic or basic depending on the pH of the food.
165
What is Denaturation of proteins?
- Loss of three dimensional structure WITHOUT breaking the PRIMARY structure;
- Loss of functional properties;
- Due to heat, acid, agitation;
- Excessive energy input may cause the protein to COAGULATE, which is more severe than mere denaturation
166
How do enzymes affect foods?
- All enzymes are proteins;
- Enzymes impact food quality, both naturally occurring & industrial enzymes that are purposefully used in food processing;
- Natural enzymes that influence food quality include PROTEASES in meat and PHENOLOXIDASES in fruits
167
What affects enzymes?
- Temperature (optimum is generally between 30-40C);
- pH (optimum generally between 7 – 10);
- Water activity
168
What is Emulsification with proteins?
- Proteins can stabilize emulsions by acting at the oil-water interface;
- Protein molecules contain both hydrophobic and hydrophilic regions, they can situate themselves between the two phases to stabilize them;
- “Like dissolves like” → Polar with polar; Nonpolar with nonpolar
169
What is Fat Reduction with proteins?
-Proteins are often used as fat replacers
170
What is Foaming with proteins?
- Proteins are good foaming agents because they can reduce interfacial tension and allow air to be incorporated into liquids;
- EX: Egg white meringues
171
What is Gelation of proteins?
- Some proteins can form three dimensional networks that allow incorporation of water and form gels;
- COLLAGEN that is used in Jell-O™ products
172
What is the Solubility of proteins?
- Functionality is often dictated by solubility, which is affected by pH, temperature, etc;
- Certain applications such as edible film manufacture require highly soluble proteins;
- Edible film – EX: Sausage casing
173
What is the Water-Holding capacity of proteins?
-Ability for a protein to bind water and is due to its hydrophilic components
174
How does water-holding capacity affect protein interactions?
- Water holding capacity is LOWEST, which means solubility is LOWEST at the ISOELECTRIC pH (pI), where the charge on the molecule is NEUTRAL;
- REDUCES the water protein interactions and maximizes the protein-protein interactions (causes protein to precipitate out of solution)
175
What is the basis for cheese production around protein pH?
- The pH is adjusted to the pI at which point the casein molecules PRECIPITATE OUT of solution and form a curd.
- Meat proteins that approach their pI (around pH 5.4) become watery or exudative due to the loss of water holding capacity.
176
How does color affect food?
- Important in our assessment of food quality;
| - can even influence other aspects of sensory perception such as flavor
177
What is Color?
- What our eyes perceive when visible light strikes an object;
- Function of the wavelengths of the light reflected by the cones of the retina
178
How do the different parts of the eye perceive color?
- Cones are sensitive to red, green or blue color (greens determined by a mixture);
- Lightness and darkness are registered in the rods
179
What can happen when light strikes an object?
Absorbed, reflected or transmitted:
- Absorbed—goes into ;
- Reflect—bounces off; glossy;
- Transmitted—goes through
* When you see color it is a mixture of the three
180
What is Visible Light?
- Occurs between the wavelengths 380nm and 780nm in the electromagnetic spectrum;
- Food reflects a variety of wavelengths, which determines the color that we perceive;
181
What gives us the ability to see shades of color?
-Ability to see many different shades of a certain color due to the fact that the three types of cones overlap in their sensitivity to color.
182
How can color be classified?
- Hue = color name;
- Chroma = clarity/purity (faded or opaque);
- Intensity = lightness or darkness
183
How is the surface of foods affected by light distribution?
-Hue = red, blue, green.
-Chroma = saturation.
- Surface of foods
•Shinny, Glossy – reflect light
•Cloudy, translucent – transmission or light through foods
184
What are the color pigment molecules?
- Chlorophylls - plants;
- Phenolics – plants;
- Anthocyanins, anthoxanthins, betalains;
- Carotenoids - plants;
- Myoglobin– animals;
* Animals can derive pigmented compounds from plant foods that they eat.
185
What is Myoglobin?
- Globular protein with an iron containing a prosthetic group called heme (iron porphyrin ring);
- Stores OXYGEN in muscle tissue, until slaughtered;
- Reddish color of muscle foods.
- Single polypeptide (Globin + Heme Iron in the middle)
186
What is a Porphryin Ring of Myoglobin?
- 4 pyrrole units;
| - Fe in center – can bond to any atom able to donate electrons
187
What happens to Myoglobin after slaughter?
Color change =
- Meat exposed to oxygen – bright red;
- Continued exposure – oxidation – greyish brown;
- Nitrate cured – pink color
* oxygen is attached to water and the meat changes to brown; Nitrates can be added to turn the meat pink.
188
What causes the color changes?
- Oxidation state of the iron, and denaturation of the globin molecule all contribute to different colors of meat;
- Oxidation reduction
ex) Fe2+ → Fe3+ loses an e- and changes color
- Also, Heme can be nitroslyated through curing, or bonded with sulfur due to bacterial action, which will affect the color
189
What causes the color change in meat with heat?
- Myosin denaturation (~120 degrees F)
| - Myoglobin denaturation (~140 degrees F)
190
How do colors indicate doneness?
- Rare – red juices
- Medium – pink
- Well – clear
- Can be misleading
191
What are the 3 groups of pigment compounds that color fruits and veggies?
- Phenolics (Anthocyanins, Anthoxanthins, Betalains)
- Carotenoid;
- Chlorophylls;
* All contain conjugated double bonds = gives color (no order, no color)
192
How do conjugated double bonds give color?
- Allows for electron resonance which in turn produces color.;
- Resonance electrons are spread across the atoms;
- Movement across carbon-to-carbon bonds gives color
193
What are the Anthocyanins (PHENOLIC)?
*Water-soluble;
-Purple to orange-red in color;
-Flavonoids;
-Contain at least two aromatic rings w/ conjugated double bonds around = COLOR;
-Valuable antioxidant
-Readily bleed into surroundings
EX: blueberries
194
What are Anthoxanthins (PHENOLICS)?
-Water soluble;
-White to yellow in color, flavonoids.
EX: cauliflower
195
What are Betalains (PHENOLICS)?
-Water soluble;
-Purple to yellow, flavonoids.
-Sensitive to heat & light
EX: beets
196
What are Chlorophyll Pigments?
- Light green to dark brownish green;
- Similar to our hemoglobin with an iron center, they have magnesium (“their blood”).;
- LIPID SOLUBLE, green, porphyrin with Mg at center plus phytol (hydrocarbon tail);
- Chlorophyll A -- bright blue green;
- Chlorphyll B - olive green
197
What changes are Chlorophyll susceptible to ?
- UNSTABLE (don't maintain characteristics well);
- Susceptible to 2 chemical changes during cooking =
- Loss of hydrocarbon tail;
- Removal of Mg from center;
- Heating can cause it to lose the magnesium then it turns brownish
198
What are Carotenoids?
-Absorbs blue and green wavelengths and we see RED;
-Lipid soluble, orange to yellow, ISOPRENES;
-Relatively stable & soluble in fats/oils
EX: tomatoes
-Seeing RED means red is NOT absorbed;
-Don't see the color in cooking water b/c LIPID SOLUBLE;
-See red on plastic b/c similar to fat
199
What is a Colorant?
-Pigment used as a food additive to impart a particular COLOR;
-Natural (ex: tumeric, annatto, paprika)
-Synthetic—not always a bad thing.
EX: Annatto -- colors cheddar cheese
200
Where can Colorants be used?
- Colorants certified as safe for use in FOOD, DRUGS, and COSMETICS;
- FDA considers ALL colorants SYNTHETICS, meaning that if the product doesn't have a natural color, must list as ingredient;
- Even if it is naturally found too
201
What are the classifications of Colorants?
- FDA classifies all colorants as either FD&C colorants or exempt colorants;
- All FD&C are SYNTHETIC
202
What are Dyes?
-Water Soluble chemicals used to color entire food products.
| EX: lollipops
203
What are Lakes?
-Precipitated pigments used to color the surface of foods or fat based products.
EX: chocolates
204
What are Exempt Colorants?
-Grandfathered in;
-Law was passed were generally accepted;
-Generally of natural origin such as annatto and grape skin extracts;
EX: Caramel color – derived from the controlled heating of glucose. = Produces a complex of compounds due to the caramelization
205
What are Cochineal Extract?
- Formerly EXEMPT as of Jan 2011 ;
- Derived from cochineal INSECTS;
- Red color is due to carminic acid, which is a PHENOLIC acid;
- Used in beverages, marinades, cookies, desserts, pie fillings, etc.
206
What is Flavor?
- Property of food and receptor mechanisms of the body;
- Involves both ODOR and SENSORY FACTORS;
- Other sensory factors all perceived by physicochemical sensors in our body;
- Sours, Salt, bitter, sweet;
- Maybe fifth UMAMI;
- Astringency might be a taste.
207
How is is Odor perceived?
- Thousands of odor compounds are sensed by olfactory receptors in the nasal cavity;
- Aroma chemicals are VOLATILE → Occur very quickly and then go away;
- Odor detection is more SENSITIVE than taste
208
What are the compounds sensed as taste?
* Water soluble and contain HYDROPHILIC functional group:
- SOUR is primarily associated with acids
- SALTY with salts
- SWEET with sugars
- BITTER with a variety of specific compounds such as quinine → Found in coffee and chocolate
209
What is Umami?
- Associated with 5’-nucleotides such as inosine monophosphate and monosodium glutamate. ;
- Active portion is glutamic acid;
- Lend added dimension of flavor to foods (SAVORY, brothy);
- First coined in 1908, skepticism continued until 2001;
- Concluded animals do have taste receptor for MSG;
- MSG blamed for “Chinese restaurant syndrome” → reduces sodium content
210
What is Astringency?
- Tactile sensation;
- TANNINS that bind with saliva = Phenolic compounds;
- Responsible for the lip puckering effect of some fruits such as cranberries → Cranberry juice is highly beneficial for treating UTIs;
- Taste of RED WINE
211
What is Pungency?
- "Spicy heat" sensation;
- Chemical compounds in cruciferous vegetables such as horseradish and especially hot chili peppers;
- *CAPSAICINOID compounds in hot pepper;
212
How is Pungency measured?
-Measured using an organoleptic (based on human sensory sensations) method = Scoville System;
-Scoville heat unit (Shu) =
•Low heat chilies: 200 – 2,500 Shu
•High heat chilies: 70,000 Shu
213
What is a Cooling Sensation?
-Sensation OPPOSITE of heat (pungency);
Characterized by the most notable compound responsible for it – MENTHOL, a cyclic alcohol;
-Binds to the temperature receptors and gives that SENSATION (not temp change);
-Minty flavor and aroma;
-Flavor in gum, baked goods, ice cream, candy.
214
What are the reactions that give Flavor to Bread?
- MAILLARD reaction;
- PYRAZINE contributes to flavor and aroma;
- LOST QUICKLY due to its volatility;
- Reason aroma of day old bread is not as pleasant as freshly baked bread;
- Production of alcohols during yeast fermentation. → Alcohols breakdown and lose flavor
215
What contributes to the flavor of cooked meats?
- Maillard products as well as amino acids, peptides, nucleotides and volatiles from cooking;
- Products of DEGRADATION of protein, lipid and other components of the muscle cells
216
Who are Food Flavorists?
- Isolate and develop flavor compounds and additives. → “Faking it”;
- Produced by heating mixtures of ingredients under controlled reactions;
- Artificial flavors, essential oils, extracts, natural flavors, oleoresins, process flavors, reaction flavors
217
What is the Top Note?
-Targeted predominate flavor characteristic;
-Process usually involves combining precursors that produce appropriate AROMOA COMPOUNDS;
Reaction flavors are generated under controlled conditions for the purpose of producing food flavor additives.
218
Artificial Flavor
Flavor produced through chemical synthesis
219
Essential Oil
Oil obtained from plant matter by steam. distillation, retaining characteristic flavor;
Concentrated natural flavor extractive
220
Extract
Flavor obtained through the use of alcohol as a solvent
221
Natural Flavor
Flavor obtained from natural sources
222
How can enzymes flavor foods?
- Flavor additives are generated by ENZYME or FERMENTATION processes;
- Flavors produced in naturally fermented foods (Chocolate, cheese, coffee, hot sauce);
- Can be harvested from bacteria, yeasts and molds that are grown industrially;
- *Yeast fermentation to produce baked bread flavor yields pure flavor extract
223
What is Flavoring?
-Substance that has a flavor of its own at the level at which it is used in a food.
EX: vanilla
224
What are Flavor Enhancers?
-DO NOT impart flavor themselves, but intensifies the flavors that are naturally present or added to foods;
EX: salt
225
What is Protein Hydrolysate?
- Protein BREAKDOWN product obtained by chemical or enzymatic action;
- Generates peptides, amino acids, etc;
- Provide flavor, nutritional value, or flavor enhancement;
- Hydrolyzed vegetable protein (HVP) – Made from soy and is used as an extender or flavoring in meat and dairy products
226
What is Flavor Encapsulation?
- Applied to flavors to offer stability, convenience and timed release;
- COATING of flavor compounds;
- Temporary PROTECTION from high heat, acid, oxygen, thus making them stable during storage;
- Used in the food industry to aid in mixing, distribution, flavor incorporation or flavor stability;
- Highly processed foods, shortens mixing and yields consistency
227
What are Off-Flavors?
-Unwanted flavor development in foods due to internal chemical changes;
-Different from normal characteristic flavors;
•Trimethylamines - a fishy off-flavor in dairy products.
•Putrescene - a rotting off-flavor
228
What is Taint?
-Result from external contamination from the environment during processing, distribution or storage
229
What is Hydrolytic Rancidity?
- Flavor DEGRADATION due to the release of short chain free fatty acids. → Breakdown of fats!!;
- Caused by heat and lipase.
230
What is Oxidative Rancidity?
- Flavor DEGRADATION due to the oxidation of unsaturated fat that results in the production of volatile aldehydes, ketones, alcohols and acids;
- Caused in part by heat and light.
231
What is Warmed Over Flavor (WOF)?
- Occurs in reheated meat products resulting in an unpleasant, stale taste;
- Due to the oxidation of phospholipids in cell membranes;
- Pork is more susceptible than beef, turkey than chicken;
- Prevented by using controlled heating, reheating and antioxidants.
232
What is Food Texture?
- PERCEPTION when a food is held by the fingers, pushed by the tongue against the palate or chewed by the teeth;
- MOUTHFEEL is related to texture as it encompasses the sensations experienced during the mastication (chewing) of food products.
233
How is Texture classified?
- Microscopic & macroscopic structure;
- Resistance to cutting force (shear force).;
- Resistance to deformation → Will the product easily change form;
- Resistance to flow, etc.
234
What is Rheology?
- Study of the flow of matter in response to applied force;
- How fluid food will flow;
- How a fluid will be sensed by the tongue;
- How long it takes for the fluid food to be cleared from the palate. → Aftertaste
235
What is Viscosity?
Resistance to flow;
- Fluids have low viscosity whereas semisolid foods have high viscosity;
- Low - milk, water
- High – jam, pudding,
- Very high – dough, taffy;
- SOLID foods do not generally flow, but can be deformed or sheared as indications of textural properties
236
What are texturizing agents?
- Ingredients that influence texture;
- Increase viscosity
- Promote gelation
- Increase firmness by water binding
- Stabilize emulsions
237
What are Water-Based Systems?
- Moisture of food and manner which it is chemically positioned has a great influence on texture;
- More FREE water (HIGH water activity), MOre TENDER and moist. ;
- INTERMEDIATE water activity foods having a dry firm texture;
- LOW water activity foods tend to be hard and crisp.
238
What are Fat-Based Systems?
-Influence of fat on texture is primarily derived from its crystalline form and melting point, which can contribute to a smooth, creamy texture;
EX: The influence of cocoa butter on the texture of chocolate.
239
What are the primary texturizing agent?
- Polysaccharides;
- Vegetable gums;
- Proteins, usually of animal origin, such as collagen and whey protein;
- Provide functionality by way of their ability to form GELS or INCREASE VISCOSITY (more solid).
240
How do Polysaccharides add texture?
-Increase the viscosity and apparent richness of fluid products;
-Carrageenan in chocolate milk creates weak gel that breaks when the milk is poured.;
-Form gels that provide essential functionality;
EX: PECTIN in jelly manufacture.
241
What are Fat Subsitutes?
*Fat Replacer
| Have the SAME physical properties as a fat and replicate fat functions (Olestra)
242
What are Fat Mimetics?
* Fat Replacer
- do NOT have all of the essential characters such as heat transfer or flavor carrier;
- DOES provide textural similarities; combination of polymers such as starch or vegetable gums and water. → Rearranged with different textural agents
243
How do sugars add texture?
- Reduce the ability for starch gelatinization or protein gelation.
- Increases viscosity WITHOUT forming gel.
244
What is Gelatin?
-Texturizing agent derived from collagen when the tropocollagen superhelix is degraded by heat, alkali or acid.;
-Dried product of collagen degradation, which forms a SOL when added to hot water;
-When cooled becomes more viscous, eventually forming a three dimensional gel;
The gel is stabilized by NONCOVALENT bonds at junction zones;
Allows water to be trapped within the open portions of the gel network
245
How does Meat Tenderization change texture?
Achieved to a degree by reducing the strength of collagen through a similar degradation of the tropocollagen molecule with the addition of HEAT and ACIDS such as lemon juice or vinegar;
-Commercial meat tenderizers contain PROTEASE which degrades both collagen and myofibrillar proteins.
246
What are food additives?
- Any substance added to food, either intentionally or unintentionally;
- Intentionally added and must be approved by the Food and Drug Administration (FDA);
- oFood additives have been used for centuries in order to achieve some purpose in the production of food products.;
- Salt, herbs/spices, sugar, vinegar;
- Irradiation? → Kills a lot of bacteria
247
What are Indirect Additives?
substances that accidentally get into a food product during processing or packaging.
248
What is Adulteration?
deliberate addition of cheap ingredients to a food to make it appear of higher quality.
249
What are Unintentional Additives?
Added accidentally, but are anticipated and addressed by the FDA.
250
What are the main uses of food additives?
1. Maintain consistency
2. Improve/maintain nutritional value (lack of or loss during processing(
3. Maintain palatability/wholesomeness (preservatives; loss due to air, bacteria,)
4. Provide leavening or control acidity/alkalinity (rising baked goods)
5. Enhance flavor or give color (spices; color additives)
251
What are the requirements guiding the use of additives?
- Safety of a food additive must never be in doubt.;
- Additive must function in food systems in accordance with its INTENDED PURPOSE under specific conditions of use;
- Must NOT diminish the nutritional value or be used to hide inferior product characteristics;
- Detectable by a specified and defined method of analysis.
252
What are Antimicrobial agents?
INHIBIT the growth of microorganisms in food products - ONLY PREVENT growth, don't kill;
EX: Sodium nitrate, sorbic acid, sodium chloride, sodium benzoate
253
What are Antioxidants?
INIHIBIT oxidation of fats or colorants that could cause a product to become rancid.
EX: BHA, BHT, ascorbic acid, tocopherols
254
What are Colorants?
Added to offset color losses during processing or to correct for natural color variations.
EX: FD&C Blue No’s 1 and 2,
FD&C Green No. 3,
FD&C Yellow No. 5, etc.
255
What are Curing Agents?
Help to retain the pink color in cured meats.
| Ex: sodium nitrate.
256
What are Flavorings?
-Natural or synthetic additives that are used for flavor production or modification.
Ex: amyl acetate (artificial banana flavor), MSG
257
What are Nonnutritive Sweeteners?
-Compounds that provide much greater sweetness intensity per amount when compared to sucrose.
EX: aspartame, acesulfame-K, saccharin.
258
What is an Act? (know)
Begins as a BILL before Congress and becomes law when president of US signs it.
259
What is a Statute? (know)
- NOT strictly law;
| - but a RULE or administrative CODE issued by government agencies at all levels
260
What are Codes?
-Collections of LAWS AND STATUTES THAT are codified for ease of administration;
EX: Code of Federal Regulation (CFR) codifies rules enacted by Congress
261
What is the Federal Register?
-Publication that details ALL NEW Federal laws and regulations.
262
What is a Proposed Rule?
- Written whenever a CHANGE is needed in an agency’s regulations;
- 60 day comment period.;
- The Federal Register reporting of proposed rules has a preamble and the regulatory text.
263
What are the steps for a PROPOSED rule?
1. Proposed rule
2. 60 day public comment
3. Clearance
4. Publish in Federal Register
5. Clearance
6. Publication
7. CFR - Codified Regulation
264
What is a FINALIZED Rule?
-FINAL version of the rule that includes any revisions from the proposed rule and indicates an EFFECTIVE date and an IMPLEMENTATION date.
265
What is Codifying the Final Rule into the CFR? (know)
- ONCE A YEAR all changes to the rules are updated into the CFR;
- The CFR is divided into 50 different titles, which are then subdivided into chapters and sections;
- USDA– Title 7 (Meats, poultry, etc.);
- FDA – Title 21 (basically everything else)
266
What are GRAS substances?
Generally Recognized as Safe;
| *Began in 1958
267
What is HACCP?
Hazard Analysis and Critical Control Points;
| *Seafood HACCP began in 1995
268
What are the first significant food legislation?
-Food and Drug Act of 1906 =
Prohibited the interstate commerce in misbranded or adulterated food, beverage, or drugs.;
-The Meat Inspection Act was passed at about the same time.
269
Federal Food, Drug, and Cosmetic Act of 1938
* 1938;
- basis of modern food law;
- Gave the FDA authority.
- Considerations for standards of identity, minimum quality, container fill, etc;
- Requiring new drugs to be shown safe BEFORE marketing.;
- Provide safe tolerances be set for unavoidable poisonous substances;
- Authorizing factory inspections.;
- Caused by Elixir of Sulfanilamide which contained solvent diethylene glycol which killed 107 people.
270
Food Additives Amendment of 1958
-Required FDA approval of food additives prior to inclusion into foods;
-Two groups of substances were exempted:
1. Prior sanctioned substances – those approved by USDA/FDA before 1958 amendment. (nitrates used to preserve luncheon meats0
2. GRAS substances - generally recognized as safe.
(salt, sugar, spices)
271
The Color Additives Amendments
Required the demonstration of safety for all dyes used in food regardless of prior history of use.
272
The Delaney Clause
Prohibited the approval of any food additive that was found to cause CANCER;
- No Gray areas for interpretation;
- Cancelled 8 additives = Veterinary drug, veterinary feed additive, flavoring agent, saccharin, indirect additives in packaging materials, and several color additives;
- No longer used since 1996 b/c of adoption of "negligible risk" by FDA
273
What deem an additive safe by "negligible risk"?
Lifetime use (70 years) presents no more than 1 in a million risk of cancer in humans.
274
1966 Fair Packaging and Labeling Act
Countered problems with underweight products or DECEPTIVE packaging practices. → Created standards for equality so people would not be undersold
275
Pesticides and Toxicants
shifted the burden of proof that pesticides were not harmful to food products to the pesticide manufactures
276
How did Cyclamates change laws?
- a previously GRAS alternative sweetener;
| - Spurred the call for review of all GRAS substances
277
What laws applied to Saccharin?
the only artificial sweetener left at the time that it was discovered to cause cancer.
o Congress had to pass a special law that imposed a moratorium on its ban, under the Delaney Clause;
-Required warning label.
-In 2000, label removed.
278
What is Red Book?
Established a more consistent policy with regard to the safety of additives relative to the risk of being carcinogens.
279
Why were Nutrition Labels started?
addressed the need to better inform the public about the nutritional value of foods.
280
How does Biotechonology apply to food law innovation?
- The FDA focuses on the safety of the food;
- Unless the practice introduces new, non-GRAS substances (e.g. allergens) that would not be otherwise in the food product
281
What are the 2 primary agencies that enforce food laws in the US?
- FDA
| - USDA
282
What are the internation food agencies?
- World Health Organization (WHO)
- Food and Agriculture Organization (FAO)
- The Codex Alimentarius Commission
283
What is the USDA?
United States Department of Agriculture;
- Responsible for the wholesomeness and safety of meat, poultry and dairy;
- Food Safety and Inspection Service (FSIS);
- Animals are inspected before slaughter and carcasses after slaughter for any sign of disease.
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What is the FDA?
- Food and Drug Administration;
- Anything that contains less than 3% of meat, poultry, or dairy, FDA controls;
- Part of the U.S. Department of Health and Human Services;
- Responsible for all food products except the ones that USDA controls;
- Responsible for the safety of all food products EXCEPT red meat, poultry and dairy products (can't recall)
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What are the 3 types of FDA recalls?
1. Class I – Dangerous or defective product that could cause serious health problems or death - intentional can go to jail (Ex: Food containing botulinum toxin)
2. Class II – Products that might cause temporary health problem
3. Class III– (most common) Products unlikely to cause health problem, but violate regulations (Ex: Package that contain less than amount stated on label
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What are the Good Manufacturing Practices of the FDA?
-Directives towards proper food processing, SAFETY is the main service;
-Gave rise to the FDA Modernization and Accountability Act of 1997 =
Requires specific support for all health claims on food!
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What is the APHIS?
Animal and Plant Health Inspection Service=
| -Protect animals and plants from pests, part of USDA
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What is the CFSAN?
Center for Food Safety and Applied Nutrition =
- Protect consumers from fraud, misinformation and unsafe food products.
- Promote innovation, component of FDA.
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What is the EPA?
Environmental Protection Agency =
| -A DISTINCT AGENCY whose mission is to assure food SAFETY, primarily through regulation of pesticides, water safety.
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What is the FCCC?
Food Chemicals Codex Committee =
- Part of to National Academies of Sciences.
- Sets standards for purity of food additives
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What is the FTC?
Federal Trade Commission =
- Enforces CONSUMER PROTECTION LAWS such as truth in advertising;
- Like a Better Business Bureau—form legal cases for you
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What is the NMFS?
National Marine Fisheries Service =
- Part of the Department of Commerce.
- Responsible for SEAFOOD quality with VOLUNTARY inspection program
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What is Toxcity?
(testing of safety)
Potential of a chemical to cause harm.
•Acute – short-term effect; rapid toxic response.
•Sub-acute - less rapid but still short term effect
•Chronic - occurs over longer period due to exposure to low levels.
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What causes Chronic toxicity?
1. Mutagenic - changes/damages DNA
2. Teratogenic - causes birth defects; affects pregnant women
3. Carcinogenic - causes cancer
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What is the Ames Test?
- Rapid test of mutagenic potential of chemicals;
- Mutagenic substances often turn out to be carcinogenic;
- Based on the ability of a potentially mutagenic substance to reverse the mutation in a strain of the bacteria Salmonella typhimurium.;
- Screening tool for MUTAGENS with follow up animal studies
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The Nutrition Labeling and Education Act of 1990
- New labeling requirements focused on calories and macros;
- Law in 1994 to allow food companies to obtain the data necessary to meet new labeling requirements;
- USDA has requirements complimentary to FDA requirements for meat and poultry.
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What is required on a nutrition label?
1. Serving size
2. Amount per serving of Fat, Saturated Fat, Trans Fat, Cholesterol, Sodium, Total Carbohydrate, Protein
3. Amount of each nutrient (except sugars and protein) as a percent of the Daily Value for a 2000 calorie diet
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What is a Daily Value?
REPLACES the term Recommended Dietary Allowance (RDA);
- Takes into account the Reference Daily Intake (RDI) and the Daily Reference Value (DRV);
- Percent Daily Value is a relative term that is used on labels to eliminate the need to know the units for each of the nutrients.
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What are the general components of a label?
- Product name and place of business
- Product net weight
- Product ingredient contents (in decreasing order of amount)
- Company name and address
- Product code (UPC code)
- Product dating
- Religious symbols
- Safe handling (“refrigerate after opening”)
- Special warning instructions (peanuts or aspartame)
* *companies have to put HOW MUCH of the product is actually in the package
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What is "Reduced"?
Nutritionally altered product contains at least 25% less of a nutrient or of calories than the regular, or reference, product.
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What is "Percent Fat Free"?
-Must be low-fat or fat-free
-Must accurately reflect the amount of fat present in 100 g of food
EX:. 2.5 g fat/ 50g food = 95% fat free
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What is "Fresh"?
- FDA regulations state that it is used only on RAW, never been frozen or heated, and contains NO PRESERVATIVES (irradiation at low levels is allowed)
- Irradiation—used for SPICES**
- Flash product with radiation for a few seconds.
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What is "Good Source"?
one serving of a food contains 10-19% of the Daily Value for a particular nutrient
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What are the health claims for "Baby Foods"?
- Broad health claims NOT allowed (unsweetened and unsalted are allowed).
- But you CAN’T use “Reduces Cholesterol” “Makes your Baby smarter” etc hah
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What are the specific approved health claims?
- Calcium & osteoporosis
- Dietary lipids & cancer
- Dietary saturated fat and cholesterol and risk of heart disease
- Dietary sugar and dental caries
- Fiber-containing grain products, fruits, vegetables and cancer
- Folic acid and neural tube defects
- Fruits and vegetables and cancer
- Fruits, vegetables and grain products that contain fiber and risk of coronary heart disease
- Sodium and hypertension
- Soluble fiber and risk of coronary heart disease
- Soy protein and risk of coronary heart disease
- Stanols/sterols and risk of coronary heart disease
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Claim = Soluble fiber from Whole Oats and Coronary Heart Disease
* Must be approved by FDA and clearly represented on label and ads;
- Presence of high levels of beta-glucan that has been shown to reduce serum cholesterol.
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Claim = Soy Protein and Coronary Heart Disease
*Must be approved by FDA and clearly represented on label and ads
-Level of 25 grams of soy protein per day has been shown to lower serum cholesterol.
Must contain at least 6.25 grams of soy protein per serving.
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Claim = Plant Sterol and Stanol Esters and Coronary Heart Disease
Must be approved by FDA and clearly represented on label and ads;
- Plant stanols and sterols have been shown to lower serum cholesterol (effective dose being 1.3 grams for sterols and 3.4 grams for stanols).
- Products so labeled must contain ½ the effective dose per serving
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What are Dietary Supps?
- Intended to supplement the diet;
- Intended for ingestion in pill, capsule, or liquid form;
- NOT for conventional food use;
- Labeled "dietary supp"
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What must be in a Diet Supp?
```
One or more of the following:
-A vitamin
-mineral
-amino acid
-a substance used to supplement the diet by increasing total caloric intake
-a concentrate
-a metabolite
-constituent,
or a combination of the above.
```
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Dietary Supplement Health and Education Act of 1994
- Defined "Dietary Supp";
- Set retail restricitons
- Mandated labeling requirements
- Safety testing
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Retail Outlets and Dietary Supps
- Can provide literature to help inform consumer;
- But CANNOT promote a specific brand
- Must be displayed with similar products
- NOT displayed with supps
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What must manufactures put on a supp label?
“This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”
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What is the Safety Testing of Dietary Supps?
- Dietary supplements are regulate much like food.;
- However, amino acids, non-nutrients, and herbs remain largely unregulated. ;
- They are not considered to be drugs and thus DO NOT go through safety testing by FDA.
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What is Cholestrin?
- Supplement that contains a natural source of a drug that had approval to lower cholesterol.
- FDA determined that the supplement was a DRUG rather than a supplement and had to be treated as such.
- Court ruled that Cholestin met the definition of a supplement as described in the DSHEA and OVERTURNED the FDA on this ban.
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What brought about the Food Safety and Modernization Act?
-One in six people in the US suffer from foodborne illness each year (CDC).
-Too many cases of preventable foodborne illness:
• 3,000 deaths
• 128,000 hospitalizations
-Outbreaks:
• Cause foodborne illness
• Disrupt sectors of food system
• Loss of public confidence
• Economic damage
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What makes the Food Safety and Modernization Act historic?
- 70 years since the last major overhaul of food safety legislation.
- Focus is on PREVENTATIVE approach, rather than reaction to problems.
- Gives FDA POWER to require recalls.
- New requirements for importers to ensure that food from ABROAD is just as safe as domestic foods.
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What are the FDA's key new authorities and mandates
1. Prevention
2. Inspection & Compliance
3. Response
4. Imports
5. Enhanced Partnerships
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Prevention
- Mandatory preventive controls for food facilities
- Mandatory produce safety standards
- Authority to prevent intentional contamination
- FDA will issue regulations to protect against intentional adulteration of food.
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Inspection and Compliance
- Mandated inspection frequency
- Records access
- Testing by accredited laboratories
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Response
- Mandatory recall;
- Expanded administrative detention = Gives FDA more flexibility to detain food that may be in violation of law;
- Suspension of registration;
- Enhanced product TRACING abilities;
- Additional RECORD keeping for high risk foods;
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Import
- Importer accountability - Imports must verify that they had ADEQUATE PREVENTATIVE controls in place
- THIRD party certification = Qualified 3rd parties can verify that a foreign facility is in compliance with US regulations.
- Authority to DENY entry
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Enhanced Partnerships
- State and local capacity building;
- Foreign capacity building;
- Reliance on inspections by other agencies;
- FDA authorized to rely on inspections of other agencies (federal, state, local) to meet requirement for increased inspections of food facilities.
