Food Science - Exam #1 Flashcards
1
Q
What is Food Science?
A
-Concerned with all quality and safety aspects of food before a person consumes it
2
Q
What is Nutrition?
A
Related to how the body uses the food
3
Q
What is Food Technology?
A
The application of the science and food processing → Choosing foods, packaging, preserving
4
Q
What is Food Manufacturing?
A
The processes that are used to convert raw materials into finished food products.
5
Q
What is the difference between Food Science and Nutrition?
A
- FOOD SCIENCE deals with food manipulations and their consequences.
- NUTRITION deals with the consequences of food components on the body.
6
Q
What is Biology?
A
The study of living things and their life sustaining systems
7
Q
How does Biology impact food?
A
Microorganisms have a great impact on food from both positive and negative standpoints. → Need to understand living things and how they will affect the foods
-Fermentation and food borne illness
8
Q
What is Chemistry?
A
The study of atoms and molecules, the structures that they can form, and the reactions in which they participate
9
Q
How does Chemistry apply to foods?
A
Foods contain a variety of molecular structures such as atoms and molecules which undergo many different chemical reactions.
10
Q
What is Physics?
A
- The study of matter and energy;
- Concerned with changes in matter under various conditions
11
Q
What is Engineering?
A
Discipline devoted to the study of momentum, heat and mass transfer, among other physical phenomenon.
12
Q
How does Engineering apply to Food Science?
A
Engineering principles are applied throughout the manufacturing operations used to process food
13
Q
When did Food Processing begin?
A
Food processing is long and varied dating back to the milling of flour more than 10,000 years ago.
14
Q
When did dramatic advances occur in food processing?
A
During the industrial age;
- 1800s canning and pasteurizing began
- 1900s freezing and drying, most progress in 1950s
- 1953 Swanson produced the first frozen meal
15
Q
Food Processing Industry
A
- Currently: 2nd largest manufacturing sector in the nation.
- $600 billion in retail sales.
16
Q
Why did the food industry originally begin?
A
Because food (and water) is the most essential necessity to life, historically the need for provision of food to avert starvation has led to the modern food industry. → Constant need for new innovation to continually provide food and water
17
Q
Who was Nicolas Appert?
A
1810;
Credited with the first large scale use of canning technology as a means to feed Napoleon’s troops
18
Q
Who was Brian Donkin?
A
- Credited with developing the TIN can which replaced the glass bottle;
- Each can had to be individually made and heated for 6 hours
19
Q
Who was Gail Borden?
A
Developed a canned milk product with added sugar that was used by soldiers during the Civil War
20
Q
What was the first form of refrigeration?
A
Ice houses
21
Q
What made Refrigeration possible?
A
Made possible through the development of compressor-based refrigeration systems in the mid 1800s
22
Q
What did early chemists first discover in living tissues?
A
Macrocomponents - proteins, lipids, carbs
23
Q
How was the importance of Vitamins discovered?
A
Treatment of what are now referred to as nutritional deficiency diseases;
- Beriberi = deficiency of Vitamin D
- Pellagra = deficiency in Vitamin B3 → Diarrhea, confusion
- Scurvy = deficiency of Vitamin C → Spongy gums, spots on skin (Very common in sailors, who ate meat and grains and no fruit and veggies)
24
Q
What is Adulterated Foods?
A
- Impure, unsafe, or unwholesome food;
- In the 1800s, some food/drug manufacturers sought to exploit and adulterate food to increase volume, weight or aesthetic quality.
25
What is Upton Sinclair's book The Jungle?
- Depicted the extent of abuse in the meat industry, was a major factor in the development of the US Food and Drug Act and the Meat inspection Act (1906).
- Attacked capitalism and the treatment of workers and the sanitation in the Chicago meat-packing industry
26
What is the function of a food scientists or food technologist?
- Applies scientific knowledge and technological principles to study food and their components.
- Tend to be the originators of most new food products
27
What drives the need for the creation of new food choices?
Consumer trends and desires
28
What areas do Food Scientists concentrate on?
- Basic Research
- Product Development
- Quality Insurance
- Processing
29
What is Basic Research?
Involves the basic sciences such as biology (including microbiology), chemistry and physics
30
What are Applied Food Sciences?
- Branch of basic research;
| - Areas such as sensory evaluation and food safety.
31
What is Product Development?
- Utilized by most food processing companies to develop new or modify existing product lines;
- Can create a totally new product or just alter the packing to make the product appear new and attractive
32
What is Quality Insurance?
- Employed to maintain and assure quality at all levels of the processing and marketing of food products.
- Includes raw ingredient specifications, company quality specifications, etc. → Meeting standards!
- Largest area of work for food science
33
What is the Scientific Method?
A systematic approach to answering the problem or question posed by the scientists and involves following specified steps
34
What are the steps of the Scientific Method?
1. Question
2. Hypothesis
3. Experimental design
4. Conduct Experiment
5. Analyze the results
6. Draw conclusions
35
What is the IFT?
Institute of Food Technology
36
What are the publication of the IFT?
- Journal of Food Science;
| - Food Technology magazine
37
What are the 5 specific areas addressed in the Journal of Food Science?
- Food Chemistry and Biochemistry
- Food Engineering and Processing
- Food Microbiology
- Nutrition
- Sensory Evaluation
38
What are Nutraceuticals?
Foods that may provide health benefits beyond their normal nutritional value, such as preventing cancer or heart disease (probiotics, antioxidants, phytochemicals etc.)
-Emerging new product in the history of food product development
-Large issue of debate on the benefits they really offer
Ex: Beta carotene in carrots is known to protect eye health
39
What are the 3 major classes of food components?
- Macronutrients
- Micronutrients
- Phytochemicals
40
What are the Macronutrients?
Protein, lipid, carbohydrate, water
41
What are the Micronutrients?
Minerals and vitamins
42
What are Phytochemicals?
Plant derived chemicals that are biologically active and are thought to function in the body to prevent certain disease processes – considered nonnutritive
43
What is MyPlate?
- Developed by the USDA as a guide to help people chose the makeup of their diet so that nutritional value is maximized and potential harm is minimized.
- Replaced the Food Guide Pyramid
44
Who were the EARLY food scientists?
- The EARLY food scientists were basic scientists who were inspired to solve problems related to food quality or safety
- Then developed in the need for new productions and food preservation
- Now university trained food scientists
45
What are the areas of work for Food Scientists?
- Food microbiology
- Food chemistry
- Food engineering
- Sensory evaluation
46
What is Food Microbiology?
The study of all aspects of microbial involvement in food, both good and bad
47
What is Food Chemistry?
The study of chemicals in food, how they are analyzed and how they impact food quality
48
What is Food Engineering?
Applies engineering principles to food processes and food processing equipment
49
What is Sensory Evaluation?
Evaluates food as perceived by the human senses of sight, smell, taste, touch and hearing
50
What in Composition?
- The substances or components found in a food or beverage.
- Food scientists have developed tables that depict the composition of a wide variety of foods;
- USDA maintains a database
51
What are Commodities?
- Useful consumer goods of agricultural origin generally referring to RAW products.
- USDA lists 14 commodities, some are processed foods
52
What are the 14 commodities listed by the USDA?
Red meats, poultry, fish and shellfish, eggs, dairy products, beverage milks, fats and oils, fruits, vegetables, shelled peanuts and tree nuts, flour and cereal products, caloric sweeteners, coffee, cocoa
53
What are Processed Commodities?
VALUE-ADDED commodities DERIVED from agricultural commodities that offer convenience, longer shelf life, and sometimes added nutrients. → People alter the original commodities
54
How do Nutritionists and Food Scientists consider foods differently?
- NUTRITIONISTS are primarily focused on the NUTRIENT CONTENT of the commodity (How much to consume, NO additives);
- Food scientists must factor in additives in order to assess their functional contribution to food products. → Give additional VALUE to the foods
55
What determines Serving Size?
Dependent on the particular food item and generally reflects the amount NORMALLY consumed. → Has NOTHING to do with what SHOULD be consumed
56
What is the Nutrition Label and Education Act?
Serving sizes are specified according to the FDA-established “Reference Amounts Customarily Consumed Per Eating Occasion”.
57
What is given in the Food Composition tables?
- Normally give composition for common quantities such as cups or oz. and also per 100g
- Unit given depends on the type of food (Fruit, veggie, grain, etc)
58
What is a Beverage?
A drinkable liquid, consumed for a variety of reasons
59
Why are Beverages consumed?
- Thirst quenching → Water especially (only thing that actually quenches thirst)
- Stimulant effect → Coffee
- Alcoholic content → Beer, wine, rum, vodka, etc.
- Health value → Fruit juice, milk
- Enjoyment → Carbonated soft drinks
60
What is Nutrient Density?
Concentration of nutrients RELATIVE to calories.
61
What makes a food or drink Nutrient Dense?
Supplies variety of protein, complex carbohydrates, vitamins & minerals without excess fat and calories
62
What is the primary component of beverages?
WATER is the primary component of beverages, but it varies among types;
- Coffee: almost 100% water
- Orange Juice: 90% water
- Alcoholic Beverages: Contains less even less water
63
What is the Degrees of Brix?
- The weight percent of pure sucrose in a solution (grams of sucrose/100 grams of beverage;
- Measured using either a refractometer or hydrometer calibrated for degrees Brix
64
Why do fruit juices need to be monitored by Degrees Brix?
- When fruit juices oxidize, sucrose molecules separate into glucose and fructose;
- Fructose is sweeter than both sucrose and glucose, therefore changing the flavor of the foods as it begins to break down → Lower quality
65
Why is the Degree Brix/Acid Ratio important?
- In fruit and vegetable juices → Ratio of SUGAR TO ACID is an important consideration for flavor;
- Measurement of quality and purity
66
What is the major agronomic crop around the world?
Cereals;
- Rice, corn, and wheat, barley, sorghum, rye, millet and oats.
- Both for human consumption and animal feed
67
What is the major nutrient component of cereals?
- Carbohydrates is the major component (>75%) of cereals;
| - Primarily in the form of STARCH, along with some simple sugars and some fiber.
68
What are the 3 major parts of the cereal grain?
- Endosperm (high in starch)
- Bran (high in fiber)
- Germ (high in lipid because this is the source of ENERGY to the sprouting seed)
69
What is the protein content of cereal grains?
Protein tends to be of lower nutritional quality due to lower levels of the essential amino acid lysine as indicated by LOW biological value → Incomplete protein that needs to be complemented;
-Compare to eggs with high quality protein which contain high biological values of complete proteins (all amino acids)
70
What is Biological Value?
-Amount of NITROGEN utilized by the body for growth
71
What is Leavening?
- production of gas (CO2) in a dough that increases volume and creates the typical texture of the bread crumb upon cooking.
- BIOLOGICAL leavening agent: Yeast
- CHEMICAL leavening agent: Baking powder, baking soda
72
What is Fruit?
-The ripened ovary that contains seeds surrounded by pulpy flesh. → Used in Dessert for typical standards
73
What are Vegetables?
-An herbaceous plant containing an edible portion (leaf, stalk, root, etc.) → Used in the MAIN COURSE for typical standards
74
What do Fruits and Veggies have in common?
- Generally have high moisture, low protein and very low fat contents. → Water composition can be up to 90%
- Having generally the same composition means they are handled for preparation and preservation
75
What are the MyPlate recommendations for Fruit?
2 cups of fruit per day
76
What are the MyPlate recommendations for Veggies?
2 ½ - 3 cups of vegetables per day
77
What are the health benefits associated with Fruits and Veggies?
- VITAMINS and FIBER which may provide protection against cancer and heart disease
- PHYTOCHEMICALS may be of greater importance as well. [Resveratrol → From fermented berries (grapes)]
78
What is Maturity?
the condition of the fruit when PICKED
79
What is Ripeness?
The OPTIMUM CONDITION of the plant in terms of food qualities such as flavor and color.
80
When are fruits and vegetables harvested?
prior to being ripe in order to facilitate transportation and storage
81
What does Quality of fruits and veggies depend on?
Quality of fruits and vegetables depends on a variety of qualitative factors such as color, size, flavor, firmness, etc.
82
What are Quantitative measures?
Measureable;
- pH
- Titratable acidity
- Moisture content – water content
- Degrees Brix – sugar content
- Microbiological determinations
- Solids content
- Component content (Ex: pectin, citric acid)
83
How are dried fruits made?
Through the process of Dehydration
84
What is Dehydration?
- Removes moisture in order to prevent microbial spoilage or enzymatic degradation. → One of the first methods of preservations
- Fruit must be HIGHLY RIPE in order to maximize the SUGAR content
85
What is Infusion?
- Additional sugar and other flavorings can be incorporated into dried fruits when dehydrated;
- Utilizes HEAT and PRESSURE to force the sugar in and the water out. → Mechanical method of substituting water for sugar
- Results in a chewy or soft texture.
- Flavor become much more concentrated
86
What are Legumes?
Edible seeds of certain flowering plants;
- Tend to be high in PROTEIN that is of greater nutritional value than most other plant proteins.
- Offer a lower fat alternative to red meats.
- Low in sodium & have high fiber, vitamin & mineral content.
- Deficient in amino acid METHIONINE
87
What is Soy commonly used for?
- Common legume;
- Used as both a source of oil and as a source of protein;
- Flour (50% protein)
- Concentrate (70%)
- Isolate (90%).
- These products are used in a variety of food processing applications such as extending meat products including hotdogs or hamburger
88
What is the phytochemical found in Soy products?
Soy protein contains an important class of phytochemical called ISOFLAVONES which may prevent heart disease and certain types of cancers.
89
What are the benefits associated with Tree Nuts?
- Now considered a healthy option similar to RED MEATS
| - High quality protein, fiber, vitamins, minerals, unsaturated fatty acids.
90
What are the popular tree nuts?
- Almonds – sweet & bitter varieties. → We consume the sweet; Bitter is poisonous
- Hazelnuts – flavor goes well with chocolate.
- Pistachios – green color.
- Walnuts – Used in baked goods and confections.
- Macadamia – very difficult to crack, commercial varieties perfected in Hawaii
91
What is Meat?
The edible flesh and organs of animals and fowls;
| Purchased whole muscle with bone, whole muscle, processed meats
92
What are the Red Meats?
?
93
What are the White Meats?
?
94
What is the nutrition content of Meat?
- High quality protein (high levels of all essential amino acids)
- many vitamins and minerals
- But is criticized for having high levels of saturated fat and cholesterol
- POULTRY has lower fat and cholesterol and has received considerable product development in recent years
95
What are Muscle Fibers?
- Held together to form myofibrils (many units of muscle fibers)
- Connective tissue surrounds the muscle fibers and provides attachment to bones and muscles.
96
What are the contractile proteins of muscle fibers?
- Myosin (THICK filament)
- Actin (THIN filament).
- These filaments combine to form actinomyosin in the contracted state. → Active stage of the muscle
97
What are the connective tissue proteins?
- COLLAGEN (white)
- ELASTIN (found more in the tendons)
- The more collagen a muscle has the tougher its texture will be.
- There is an increase in connective tissue with age and exercise
98
What are Meat Emulsions?
- Food system in which two normally immiscible substances (usually fat, or oil and water) are caused to be mixed together using physical and chemical means. → Hot dogs, sausages, hams
- Many processed meats are examples of meat emulsions which contain chopped meat mixed with water, fat and other additives
99
What are Finfish?
-Found in fresh or salwater
100
What are the types of Shellfish?
- Mollusks – clams, oysters, scallops
| - Crustaceans – lobster, shrimp, crab and crawfish
101
What is the nutrient content of FISH?
- High in protein and low in fat.
- Some finfish have higher fat content, but is high in POLYUNSATURATED FATS which is believed to help prevent heart disease
102
What are fish high in polyunsaturated fats?
Fish typically live in a low temperature, so the fats in their bodies need to NOT coagulate at those low temperatures
103
Why are Finfish so perishable?
- Microorganisms are PSYCHOTROPIC, which means that they can grow at refrigerated temperature;
- Fish struggle and use of glycogen stores when dying, so less lactic acid produced post-mortem, so pH doesn't decrease allowing bacteria to grow;
- Unsaturated fatty acids undergo lipid oxidation and become rancid
104
What compound of RANCIDITY causes the "fishy" smell?
-Trimethylamine oxide (TMAO) in their fat that decomposes to form trimethylamine (TMA)
105
What is contained in the Egg WHITE?
- Contains almost no lipid, high protein quality;
| - High quality protein due to the need for the chick to be able to provide for itself until it is born
106
What is contained in the Egg YOLK?
- Most of the fat which accounts for 75% of total calories.
- Major categories are neutral lipids, phospholipids (lecithin) and cholesterol;
- Lecithin is used as an emulsifier in the food industry
107
How is egg QUALITY determined?
-Fresh, high quality eggs have a THICK egg white and will NOT separate out when cracked
108
What are Haugh Units?
-Height of the thick white relative to weight is used as a measure of quality
109
What is Candling?
- Process for assessing the quality of UNBROKEN eggs;
- Egg is passed in front of a light, which illuminates its contents
- Can see the shape, location and size of the yolk, check for cracks
110
What is the GRADE of an egg related to?
- NOT related to the FRESHNESS of the eggs, but more based upon the quality of the shell
- For freshness, may more attention to the expiration date
111
What is the composition of Milk?
- 88% water
- 3.3% protein
- 3.3% fat
- 4.7% carbohydrate
- 0.7% ash
112
What is Homogenization of milk?
- Creates an emulsion of the fat in milk distributed throughout the aqueous serum and therefore stabilizing the phospholipids and proteins in suspension;
- If not, fat will settle out on the top
113
What are the main nutrients found in Milk?
-Good source of the fat soluble vitamins A, D, E, K (fortified with D) and carotenoids.
114
What is milk sugar?
-LACTOSE which is a disaccharide that has LOW SWEETNESS and LOW SOLUBILITY.
115
What is Lactose Intolerance?
- problem in many parts of the world, which is due to a lack of the enzyme lactase.
- Cannot break down WITHOUT ENZYMES and will be FERMENTED in the large intestine
116
How is fluid milk classified?
-By FAT CONTENT and must have a minimum of 8.25% milk solids not fat (MSNF), which includes protein and carbohydrate
117
What are the fat-content based varieties of fluid milk?
- Whole milk (3.25% fat)
- Reduced fat (2%)
- Low fat (1%)
- Fat-free (0.5%)
118
What are other forms of milk?
- Cultured milk (buttermilk, yogurt, sour cream)
- Evaporated
- Sweetened condensed
- UHT (ultra-high temperature)
- Nonfat dry milk → Reduce half the water content and then sprayed into a chamber that evaporates the remainder of the water
119
What are the major proteins of milk?
- Casein (80%)
| - Whey (20%)
120
How is Casein precipitated out of milk?
- Precipitates as curd at a pH of 4.6.
- Microorganisms or acid can cause the reduction in pH → bacteria producing lactic acid
- Enzyme called RENNET (originally derived from calf stomachs) can be used to precipitate casein.
121
How is Ice Cream made?
-From CREAM (must be at least 18% milk fat) and other ingredients to create a complex colloidal system
122
How is Ice Cream a Complex Colloidal System?
- Contains a variety of components that would NOT be soluble.
- Includes air, water, fat, proteins and a variety of other ingredients such as flavoring, stabilizers, additional milk solids, emulsifiers, colorings.
123
What is Butter?
- Dairy spread made from either sweet or sour cream
- Churning ruptures the protein film that surrounds each fat globule which allows fat to join
- WATER-OIL Emulsion of 80% fat and 18% water
124
What is Margarine?
- Essentially simulated butter that has 80% fat (animal fat, vegetable oil) → Created when there was a shortage of butter in the 1800s
- Oil is churned with cultured & pasteurized milk or whey.
- Used to be considered a healthier alternative to butter → Because the oils were UNSATURATED
125
What is Hydrogenation?
- Process that turns unsaturated fatty acids into straight chains TRANS fats, which are even more unhealthy than saturated fatty acids
- Promotes LDL cholesterol (Bad cholesterol)
126
What is Cheese?
- The fresh or matured product obtained by draining the whey after the coagulation of casein
- RENNET from calf stomachs, where milk was originally stored caused the casein to precipitate out and the discovery of cheese
127
What is the RIPENING of cheese?
-Aging of cheeses which allows the development of important flavor and textural changes that take place that often characterize the cheese
128
What are Natural SOFT Cheeses?
- Produced simply by clotting the casein by reducing pH.
- Ex: cottage cheese, cream cheese, Roquefort
- Roquefort is one of the most famous cheeses in the world, produced using sheep’s milk and Penicillium roquefort mold that is inoculated after the clotting step.
129
What are Natural HARD Cheeses?
- Hard textured cheeses such as cheddar and Swiss are typically aged to reduce moisture content
- Mild to sharp flavors depends on the length of aging → Sharp require much longer aging making them more expensive
130
How is Cheddar cheese made?
(HARD cheese);
- Cheddaring process that involves repeated CUTTING of the curd to help remove the whey.
- Characteristic orange color is from a seed pod extract called ANATTO
131
How is Swiss cheese made?
(HARD cheese);
- Includes several microorganisms;
- Streptococcus thermophiles and Lactobacillus bulgaricus (starter culture)
- Popionibacterium shermannii produces the characteristic holes
132
What is Processed Cheese?
- When two or more natural cheeses are blended, usually with water and emulsifiers added;
- EX: American cheese;
- If too much water is added it is labeled “cheese food”
133
What is the nutrient content of Chocolate and Confections?
- NOT traditionally consumed for nutritional purpose;
| - Dark chocolate (85%) is considered the healthiest due to the lack of sugar and milk
134
How are confections (candies) made?
- Begin with a SUGAR solution that is supersaturated by heating to a high temperature;
- Can be Crystalline (hard) or Noncrystalline (soft or gummy)
135
How are CRYSTALLINE candies made?
- The sugar solution is cooled in a controlled manner and agitated at an appropriate temperature to cause microscopic crystals to form.
- Fudge and rock candy are examples of crystalline confections.
136
How are NONCRYSTALLINE candies made?
- The sugar solution is cooled rapidly or is produced using interfering agents such as fat or proteins or invert sugar, which prevents crystal formation. → Other solution and compounds between the crystals prevent the rigid structure
- Gummy bears and peanut brittle are examples of noncrystalline confections
137
What is Nutrition?
the study of foods and their contribution to health and disease.
138
What are Essential Nutrients?
Must be obtained from FOOD. → Can’t just naturally metabolize them
139
What are the Macronutrients?
Protein, carbohydrate, lipid, water → Require in high amounts
140
What are the Micronutrients?
Vitamins and minerals. → Require in very small, sometimes trace amounts
141
What are the functions of Nutrients?
- Form body structures → bone, muscle
- Serve as regulators → enzymes, hormones
- Provide energy → calories
142
What is Malnutrition?
-Implies an imbalance of nutrients in the body;
-Over-nutrition = excessive nutrients;
-Under-nutrition = deficiency of nutrients;
EX: Rickets - Vit. D deficiency
143
What are the Dietary Guidelines for Americans?
- First published in 1980 (by USDA and DHH) and revised every ten years;
- MyPlate (by USDA) is a tool to illustrate the Dietary Guidelines
- Provides consumer with a method of how to balance a healthy diet between veggies, fruits, grains, proteins, and dairy
144
What are the USDA recommended intakes?
- 6 oz. grains with at least ½ your grains whole
- 2 ½ cups of veggies
- 2 cups of fruit
- 3 cups of dairy
- 5 ½ ounces of protein (meat and/or beans)
- Should consume most of fats from seafood and other polyunsaturated sources
145
What is Digestion?
- Accomplished for the most part by digestive enzymes which are responsible for the breakdown (hydrolysis) of the major food components;
- Enzymes CAUSE reactions, but are NOT USED themselves
146
What are the categories of enzymes found in the body?
- Amylases - starch
- Peptidases - protein
- Lipases - lipids
147
What is Bioavailability?
The degree to which a nutrient is digested and absorbed
148
What is Absorption?
Passage of nutrients from the digestive tract to the blood stream facilitated by the mucosal cells of the intestine
149
What is Simple Diffusion?
- Small lipids/water cross freely into mucosal cells;
| - NO energy require, but simply pass through mucosal cells
150
What is Facilitated Diffusion?
A carrier is used to transport water-soluble vitamins to transport them to mucosal cells
151
What is Active Transport?
-Causes nutrients (glucose, amino acids) to be absorbed into mucosal cells with cost of energy input. → Absorbed by mucosal cells and must have energy input
152
What is Transport?
The movement of nutrients from the mucosal cell to the rest of the body through the blood or circulatory system which facilitates metabolic processes
153
How does molecule SIZE effect transport and absorption of nutrients?
- SMALL can move directly into the blood, but LARGER such as lipids have to be packaged into carrier molecules and routed differently;
- EX: Lipids tend to be very large and must have carries and travel through the Lymphatic system
154
What is Homeostasis?
- A state of chemical and metabolic equilibrium;
| - Maintained by hormone regulators such as insulin
155
How is Glucose homeostasis achieved?
- When blood glucose levels need to increase, Glucagon (hormone) will initiate the breakdown of stored glycogen;
- When we eat, pancreas releases Insulin, which causes cells to uptake glucose and lower blood glucose levels
156
Who regulates Food Labels?
- FDA (21 CFR 101);
| - CFR – Code of Federal Regulations
157
How are nutrients listed on food labels?
- % of daily value from one serving;
- Originally created in 1973, mainly focused on vitamins and minerals (which were considered to be of concern for deficiency; Now more focused on macronutrients and limiting their intakes)
158
What is Daily Value?
- Related to the RECOMMENDED AMOUNT of essential nutrients or RECOMMENDED MAXIMUM of nutrients that could have adverse effects at higher levels
- EX: Sodium, fat, saturated fat and cholesterol
159
What info must be provided on Food Labels?
- Product name
- Place of business
- Net weight
- Ingredients (high to low amounts)
- Company name/address
- Product code
- Dating
- Religious symbols
- Safe handling
- Special warnings (7 allergens)
160
What is the most essential nutrient?
- WATER
- Body is ~60% water
- Raw meat ~75% water
- Fruits/Veggies ~90% water
161
Where is water found in the cells?
Every cell has water in (intracellular) and around it (extracellular)
162
What are the 5 functions of water?
- Regulates body temp
- Lubricates eyes, spinal cord, GI tract, joints
- As a medium for metabolic reactions
- Participates in metabolic reactions (e.g. hydrolysis)
- As a carrier for nutrient transport
163
What is Metabolic Water?
- Is produced by the metabolism of molecules in the body.
- 100g glucose about 60 mL of water
- 100g fat more than 100 mL of water
164
What are Electrolytes?
- Charged minerals that exist in the intra and extra cellular fluid that regulate water content.
- Intracellular main electrolyte = Potassium
- Extracellular main electrolyte = Sodium
165
What maintains cell HYDRATION?
-Proper balance of intra and extra cellular electrolytes is critical to the proper HYDRATION of cells.
166
How does DEHYDRATION in the body occur?
- Dehydration results in a movement of electrolytes and water from INTRACELLULAR to EXTRACELLULAR space. → Causes muscle cramps;
- Electrolytes are become concentrated in the EXTARCELLULAR space
- Water starts moving OUT of cells into EXTRACELLULAR space in effort to balance
- Can lead to kidney failure due to high concentrations
167
What are Carbs made of?
-Carbon, hydrogen and oxygen molecules in the approximate ratio Cn(H2O)n.
168
What are the Simple Sugars?
-Monosaccharides and Disaccharides;
169
What are the Monosaccharides?
- Glucose (primary nutrient)
- Fructose
- Galactose
170
What are the Disaccharides?
- Sucrose or table sugar (glucose + fructose)
- Lactose or milk sugar (glucose + galactose)
- Maltose (glucose + glucose)
171
What does Glucose provide?
Can provide immediate energy, stored as glycogen to be used later or converted to fat.
-From fruits, milk, veggies, and refined sugars (those that only provide energy and no nutrients)
172
What are Polysaccharides?
- Complex carbs;
- Long chains of monosaccharides;
- Provide other nutrients besides energy;
- Starch (digestible)
- Cellulose (nondigestible)
- Fibers
- Pectins
173
What is Dietary Fiber?
The residue of plants left undigested after consumption of edible fiber.
174
What are Insoluble Fibers?
- Absorbs water and swells up.
| - Whole grain foods, nuts, potato skins
175
What are Soluble Fibers?
- Forms gel-like solutions as they dissolve in water.
- Delays food transit through the intestinal tract.
- Slows glucose absorption
- Lowers cholesterol levels
- Found in legumes, oats, broccoli, potatoes
176
What is Glycemic Index?
- The relative ability of a food to raise blood sugar;
- The glycemic index is related to the ease with which a food is digested and absorbed.
- Foods high in simple sugars tend to have HIGH glycemic index.
177
What are Lipids?
-The most concentrated source of energy → 9 kcal/gram
-Carry essential FAT-SOLUBLE vitamins. → Vitamins A, D, E, K;
-Hydrophobic (INSOLUBLE) and act as cellular membrane to control water flow;
-
178
What other compounds are contained in lipids?
- Essential fatty acids = MUST consume;
- Cholesterol = metabolic precursor (hormones)
- Also phospholipids, sterols, waxes, etc.
179
What are Fats?
- SOLID at room temp;
| - Butter, lard, margarine, shortening
180
What are Oils?
- Liquid at room temp
| - Corn oil, olive oil, etc.
181
What are Lipids composed of?
- Composed primarily of C, H, O;
- MORE HYDROGEN than in carbohydrates, which is why they have higher calories per gram
- More hydrogen = more energy
182
What are Glycerides?
- Make up the majority of lipids in most food products;
- Primarily triglycerides
- Some diglycerides
183
What are Triglycerides?
- Glycerol backbone + 3 fatty acids;
| - Attached fatty acids determine the properties
184
What are the major properties of Lipids?
- Hydrophobic or insoluble in water
| - Nonpolar (no charge)
185
What makes water a dipole?
- Polar;
| - Positive charge in the H molecules and negative charge in the O molecule.
186
What are Saturated Fatty Acids?
All carbons are FULLY saturated with hydrogen.
187
What are Monosaturated Fatty Acids?
- ONE carbon pair possesses a DOUBLE bond
| - Typically from vegetables
188
What are Polyunsaturated Fatty Acids?
-TWO or more carbon pairs have a DOUBLE bond
189
What are Essential Fatty Acids?
- Cannot be made by the body
- Omega 6
- Omega 3
190
What are Essential Fatty Acids made used for?
From these fatty acids all other metabolically important lipid derived components can be made.;
- Lubricate joints;
- Protect from heat loss
- Provide energy
- Building blocks of other fats
191
What is the Recommended intake of Essential Fatty Acids?
- Recommended is 4:1 (Omega 6:3);
- A higher intake of Omega 6 causes a competition for absorption because they compete for the same enzyme but we require more Omega 3
- Too much Omega 6 → Potential for Arthritis, Inflammation, Cancer
192
What is Dietary Cholesterol?
- Criticized as a cause of heart disease
| - Cholesterol levels are NOT just dependent upon consumption, but also determined by how much your body manufacturers
193
What are Lipoproteins are related to HEART DISEASE?
- HIGH levels of low density lipoproteins (LDL) - move cholesterol from the liver. → Bad
- LOW levels of high density lipoproteins (HDL) - move the cholesterol back to the liver. → Good; want high levels!
194
What are Trans-fatty acids?
- Refer to the geometry of the unsaturated bond in the fatty acid;
- Location of the hydrogens in the chain is chemically altered
195
What are CIS fatty acids?
-Most unsaturated bonds in nature have the hydrogen on the SAME SIDE of the carbon chain
196
What are TRANS fatty acids?
-When the hydrogen are on the OPPOSITE of the carbon chain
197
What is Hydrogenation?
- Adds hydrogen to some of the double bonds and hardens the oil;
- Nickel is used a the catalyst for the reaction of unsaturated fats under pressure forcing the rearrangement of the hydrogen molecules
198
What are the main sources of trans fatty acids?
-Hydrogenated vegetable oils
199
What are the health effects of Trans Fats?
-RAISE LDL and LOWER HDL in the blood
200
What is the protein composition in the body?
- About 16% protein;
- Responsible for the majority of the metabolic processes;
- Made of approximately 20 different amino acids that are bonded together by peptide bonds
201
What is the structure of Amino Acids??
- Amino (NH2)
- Carboxyl (COOH)
- Hydrogen
- Varying side chains
202
What are the Essential Amino Acids?
- The body cannot synthesize 9 of the amino acids, thus are considered essential;
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
203
How does the body utilize proteins?
-The body utilizes dietary protein by breaking it down into its component amino acids
204
What are high quality proteins?
Proteins that possess ALL of the essential amino acids at high levels;
205
What are Complimentary Protein Source?
- Adding low protein sources that together meet the need for all of the essential amino acids → Add together to consume all essential amino acids
- Ex: legumes and grains.
206
What is Biological Value?
- A measure of protein quality;
- Determined by how much nitrogen is consumed versus how much is excreted to calculate how much is utilized by the body;
- Measured in animal models (rats and mice);
207
What is the reference for Biological Value?
-Egg Protein is the reference protein assigned a value of 100
208
What is Nitrogen Balance?
- An indication of whether or not an individual has proper protein intake;
- When in homeostasis the intake of nitrogen from protein will equal the excretion of nitrogen
209
What is indicated by Negative Nitrogen Balance?
- INSUFFICIENT amounts of essential amino acid consumption
- Body begins breaking down existing protein for synthesis or energy;
- Releasing the nitrogen stored in the body proteins indicating endogenous protein catabolism
- Results in INCREASE of Nitrogen excretion in urine →Can severely damage kidneys
- Indicator of MALNUTRITION
210
What are Vitamins?
- Small organic compounds that are essential to metabolic processes and must be obtained from food;
- Work in a variety of ways.
- Antioxidants, coenzymes (activates enzymes). → Must have for bodily reactions!
211
What are the Water Soluble Vitamins?
All of the B vitamins + C
212
What are the Fat Soluble Vitamins?
A, D, E, K
213
What are Minerals?
- INORGANIC substance;
- Fewer than twenty are nutritionally important.
- Act as cofactors, main components of bone (calcium), and regulates of electrolyte balance (potassium and sodium)
214
What are Sugar Alcohols?
- Have between 1.5 and 3 kcal /g, DO NOT contribute to dental carries and have a cooling flavor.
- Sorbitol and mannitol
215
What is Acesulfame K?
- Highly sweet, heat stable, bitter aftertast;
| - NOT metabolized in the body and contributes NO calories
216
What are Aspartame?
- Dipeptide of aspartic acid and phenylalanine, 200 times sweeter than sugar;
- Contributes 4kcal/gram
217
What is Saccharin?
- The first artificial sweetener,
- Once banned because it was believed to cause cancer;
- Removed the ban in 2000 when determined that cancer was ONLY produced in rats, not in humans
- Sweet’N Low.
218
What is Sucralose?
- Chlorinated sucrose, heat stable, no aftertaste. → Made by substituting OH- groups on Surcose with Cl-
- Currently occupies more than 50% of the sugar alternative market.
- Splenda
219
Why were Fat-Replaces Created?
- Health conscious consumers demand a wide variety of low fat food alternatives.
- Consumers want to not consume the fat and calories, but maintain the taste
220
What are Carb-based Fat Replacers?
- Tend to form gels or increased viscosity
- Gums, fibers, pectin
- Used primarily in baked products and meats
- 4 kcals/gram
221
What are Protein-based Fat Replacers?
- Blending or microparticulation can be used to create fat like TEXTURE.
- Generally can not tolerate high heat → Mainly used in dairy products
- 1.5-4 kcal/gram
222
What are Fat-based Fat Replacers?
- Mimic fats more precisely, contain less or no calories.
| - Can be heated and used for frying
223
What is Olestra?
-Fat-based fat replaced synthesized from Sucrose bound with fatty acids chains of 6, 7, or 8 carbons yielding less calories per gram
224
Why were fat-replacers created?
- Health conscious consumers demand a wide variety of low fat food alternatives.
- Consumers want to not consume the fat and calories, but maintain the taste
225
What is the place of fat replacers in the diet?
- The jury is still out on the utility of fat replacers:
- Reduce calories from fat and total calories
- Their use in unhealthy foods causes an increase in these foods! → The lower calorie intake makes them so appealing
226
What is Metabolism?
-Refers to the degradation (catabolic reactions) of FOOD components and the Synthesis (anabolic reactions) of NEW compound
227
What is Energy Metabolism?
-The way the body derives energy from the macro-components (carbohydrate, protein, lipid)
228
What is a Calorie?
- Kilocalorie;
- The amount of energy required to raise the temperature of one kilogram of water one degree Celsius;
- PRO - 4kcals/g;
- Carb - 4 kcals/g;
- Fat - 9kcal/g
- Alcohol - 7 kcal/g
