Food Science Test 1

  1. Nicholas Appert
    • Food Pioneer
    • Experimented with food preservation
    • Succeeded with soups, jams, dairy products, syrups
  2. Canning
    • Place product in a can and place it in boiling water
  3. Louis Pasteur
    • Food Pioneer
    • Chemist and microbiologist
    • Demonstrated that fermentation was caused by microorganisms
    • Treated milk to destroy spoilage organisms
  4. Careers in food science
    • Food engineer
    • Food regulation
    • Food analysis
    • Sensory Science
    • Brewing
  5. What is Food?
    Complex mixture of chemicals that an organism takes in and assimilates to promote growth, expend energy, replace worn or injured tissue, and prevent certain diseases
  6. What is food made up of?
    • Water
    • Proteins
    • Carbohydrates (97% of food's mass)
    • Lipids
    • The rest is made up of thousands of different compound
    • -staste
    • -odor
    • -color
    • Vitamins and minerals also exist and are important in many body functions
  7. Nutrition
    Nutrition: The composition of foods and the reactions that lead to changes in their constitution and characteristics BIOCHEMISTRY
  8. Western disease
    • too many or calories from saturated fats
    • high rates of obesity leads to western disease
    • USDA developed guidelines to help in planning a healthy and balanced diet
    • Dietary Guidelines for Americans
    • Food Guide Pyramid
  9. Proteins
    • Chief constituents of muscle and other tissue
    • Major components of enzymes
    • Part of extracellular and intracellular structures in animals
    • Made up of amino acids
    • Proteins are made up of amino acids linked by peptide bonds
    • Required for cell growth, repair and maintenance
    • Sequence of amino acids in a protein chain determines the functionality of that protein
    • A total of 20 amino acids found in proteins
  10. Protein Quality
    • Not all proteins supply the needs of the body“High Quality” proteins provide all essential amino acids needed for to support protein tissue formation
    • Animal Protein = High Quality  
    • Plant Protein = Not Complete
    • To form proteins all amino acids necessary have to be there
    • Essential amino acids are NOT!!!!! synthesized by the body, they are supplied from food
  11. Essential Amino Acids
    • 1.Histidine
    • 2.Isoleucine
    • 3.Leucine
    • 4.Lysine
    • 5.Methionine
    • 6.Phenylalanine
    • 7.Threonine
    • 8.Tryptophan
    • 9.Valine
  12. Nonessential Amino Acids
    • 1.Alanine
    • 2.Arginine
    • 3.Asparagine
    • 4.Aspartic acid
    • 5.Cysteine
    • 6.Glutamic acid
    • 7.Glutamine
    • 8.Glycine
    • 9.Proline
    • 10.Serine
    • 11.Tyrosine
  13. Protein Primary Structure
    Linear sequence of amino acids

    Look at picture
  14. Protein Secondary Structure
    Shape of a coiled helix: Formed by hydrogen bonds between C=O and the NH groups

    Look at picture
  15. Protein Tertiary Structure
    Three dimensional structure of a protein: Results from the folding of a chain over itself

    Look at picture
  16. Protein Quaternary Structure
    Quarternary structure is only present if there is more than one polypeptide chain

    Look at picture
  17. Proteins cont.
    • Molecules are quite fragile
    • Food scientist must be aware of reactions due to exposure to:
    • -Heat
    • -Acids
    • -Salts
    • -Physical forces
  18. Denaturation
    • Loss of secondary, tertiary, and quaternary structure
    • Caused by heat, acids, solvents, salts or surface force
    • Loss of biological activity and changes in physical properties such as solubility
  19. Food Applications of Denaturation
    • Control is essential to food scientists
    • Inactivation of enzymes --->“Blanching”
    • Cheese and yogurt result from protein denaturation
    • Whipping of egg whites to foam
  20. Carbohydrates
    • They have a composition of Cn(H2O)n
    • They are a source of energy in our diet
    • Digestible CHOs provide 4 Kcal/g
    • Important carbohydrates for nutrition: sugars, starches, dextrins, glycogen
    • Fiber: Non-digestible, does not supply calories
  21. Sugars
    • The simplest forms of CHO’s 
    • Can not be broken down to any smaller carbohydrates
    • Called Monosaccharides
    • Most common ones in foods are called hexoses (six carbon sugars)
  22. Monosacharides
    • Glucose
    • Fructose
  23. Disaccharides
    • Two monosaccharides linked together
    • Composed of either two units of the same monosaccharide or two different monosaccharides
    • Bond is called a glycosidic bond!!!!!!
  24. Polysaccharides
    • More than two sugars linked together are called Oligosaccharides
    • Very large molecules are called polysaccharides (10 or more units)
    • Not sweet
    • Texture
    • Viscosity
    • Mouthfeel
    • Consistency
  25. Starch
    • Starch is the most important polysaccharide from a nutrition point of view (storage CHO in plants)
    • Main source of calories in the human diet
    • A polymer of glucose
    • Composed of two polymers: amylose and amylopectin
  26. Starch cont.
    • Not soluble in cold water
    • When heated the starch molecules sweell and gelatinize
    • Viscosity increases forming a paste
    • When cooled a gel is formed
  27. Food Applications of Starch
    • Pastes used to thicken foods
    • Gels are modified and used to impart desired texture
  28. Glycogen
    • An animal starch
    • Stored in the muscles and available for immediate use as energy
    • Excess CHO consumption
    • Excess glycogen
    • Excess CHO is converted to FAT!!!!
  29. Fiber
    • Non-digestible carbohydrates
    • Water Soluble
    • -Lower serum cholesterol
    • Water Insoluble
    • -Reduces chances of colon cancer
    • -Increases bulk
  30. Lipids
    • Not soluble in water
    • Soluble in organic solvents
    • Contain 9 calories/gram
    • Glyceryl esters of fatty acids
    • Glycerol
    • Fatty Acid
    • Triglycerides
  31. Fatty Acids
    • Saturated fats in the diet lead to increased cholesterol levels
    • High cholesterol levels are a contributory factor in heart attack, stroke and coronary problems
    • Ingestion of trans-fatty acids is linked to increases in cholesterol levels
  32. Role of Fats in Food
    • Carriers of flavor
    • Carry fat soluble vitamins
    • Texture and mouthfeel
    • Heat transfer
  33. Vitamins
    • Chemicals that are needed in very small amounts
    • Should be consumed through our food
    • Two different categories:
    • 1.Fat soluble
    • 2.Water soluble
  34. Fat-Soluble Vitamins
    • Vitamin A
    • Vitamin D
    • Vitamin K
  35. Water-Soluble Vitamins
    • B vitamins
    • Thiamin
    • Riboflavin
    • Niacin
    • Vitamin B6
    • Pantothenic acid
    • Folic acid
    • Biotin
    • Vitamin B12
    • Vitamin C
  36. Microorganisms
    What are the main ones that have an effect on food?
    • Bacteria
    • Yeasts
    • Molds
    • Virus
    • Algae
    • Protozoans
  37. Microorganisms
    • Bacteria that break down food
    • use food as a place to live out their life cycle(feed and reproduce)
    • main cause of food deterioration
    • Produce changes in food
    • -Desirable 
    • -Undesirable
  38. Bacteria, Yeast, and Mold
    • Bacteria, yeast and mold
    • ▫Under optimum conditions, the MOs reproduce and in the process synthesize by-products▫
    • ▫Ferment sugar, hydrolyze starches, hydrolyze fats, digest proteins, form acid, produce gas, produce toxins
  39. 4 Bacterial Shapes
    • Rods
    • Vibrios
    • Spherical (cocci)
    • Spirochaetes
  40. Mold Cells
    Molds are multicellular
  41. Yeast Shapes
    • Spherical and cylindrical
    • Exist as either single cells or chains
  42. Bacterial Reproduction
    • Occurs via binary fission
    • Under favorable conditions doubling rate can be 20 minutes
  43. Mold Reproduction vs. Yeast
    • Molds: 
    • Reproduce by means of spore formation
    • Sexual or Asexual
    • Yeast:
    • Budding
    • Fission
    • Spore formation
  44. Vegetative Cells vs. Spores
    • Vegetative:
    • ▫Active, reproducing, metabolizing
    • ▫Sensitive to environmental changes
    • Spores:
    • ▫Dormant state
    • ▫Concentrated forms of their vegetative state
    • ▫Formed when conditions are unfavorable
    • ▫More resistant to heat, acid, pressure
  45. Environmental Conditions for microorganisms
    • pH
    • Nutritional requirements
    • Temperature
    • Water
    • Oxygen
  46. pH
    • Growth and rate of growth are highly affected
    • Have an optimum pH at which they grow rapidly
    • Ranges where they will not grow
    • Molds, Yeast: grow best in acid mediums
    • Bacteria: many grow at neutral or slightly alkaline pH
  47. Nutritional requirements for Bacteria and Yeast
    • Bacteria: use nitrogen and CO2 from air
    • Yeast: Yeasts: derive their nitrogen from lysisne (amino acid)
    • Yeast and mold grow in high concentrations of sugar
  48. Temperatures for bacteria
    • Psychrophiles: grow fastest around 68 – 77 °F
    • Mesophiles: grow best around 98 °F
    • Thermophiles: grow between 113 – 160 °F
    • Mesophiles cause disease in animals
    • Growth rates decrease at the low and high ends of the T range
  49. Water and Microorganisms
    • Microorganisms only grow in aqueous solutions
    • Grow in available water found in food
    • Water activity (aw): express availability of water
    • Low water activity limits the growth of microbes–
    • -Salt
    • -–Sugar
    • -–Drying
  50. Anaerobic vs. Aerobic Bacteria
    • Anaerobic Bacteria: Won’t grow in the presence of Oxygen
    • Aerobic Bacteria: Need oxygen to grow
    • Molds: require oxygen
    • Yeast: grow best in aerobic conditions (some grow without it)
  51. Food Infection vs Food Intoxications
    • ▫Infection – microorganism is present in the food at the time of consumption, grow in the host cause disease –E. coli O157:H7, Listeria, Salmonella
    • ▫Intoxication – microorganism produces toxin in the food prior to consumption, cause disease upon ingestion–Staphylococcus aureus, Clostridium botulinum, Aspergillus flavus
  52. Reasons for Food-Borne Illness
    • Food handlers poor personal hygiene
    • Unclean equipment and work area
    • Foods not adequately processed
    • Cross-contamination
    • Lack of support from management
  53. E. Coli
    • Nonsporeforming rods
    • Motile
    • Abdominal pain, diarrhea, fever, vomiting Main source humans and animals
  54. Listeria monocytogenes
    • Rod shaped
    • Grows under conditions of refrigeration
    • Meningitis, septicemia, spontaneous abortion
    • Raw milk, unpasteurized cheeses, lunch meat
  55. Staphylococcal Poisoning
    • Staphylococcus aureus is responsable
    • Nausea, vomiting, abdominal cramps, diarrhea
    • Incubation: 1 to 7 hours
    • Toxin produced is not destroyed by normal cooking
    • All foods except acid products are susceptible
    • Most often: ham, bakery goods with egg, chicken products, potato salad, cheddar cheese
    • Humans are the primary reservoirs (nose, hands, arms, mouth, throat)
  56. Botulism
    • Occurs rarely but high mortality rate (30%)
    • Vomiting, constipation, double vision, abdominal distention, raw sore throat
    • Severe cases produce affect the breathing mechanism and the heart
    • Clostridium botulinum
  57. Clostridium botulinum
    • Anaerobic
    • Sporeformer
    • Produces toxin
    • Some strains can grow low temperature
    • ▫Seven different types: A through G▫
    • -Only a few nanograms can cause illness
    • Spores from varied sources
    • -▫Food, dust, soil
  58. Clostridium botulinum
    • Toxin: Destroyed by boiling
    • Spores: Higher temperatures to be inactivated
  59. Microorganisms in Food – Desirable Changes
    • Bacteria, yeast and mold can produce desirable changes in foods
    • Lactic acid bacteria
    • ▫Yogurt, sausages, sauerkraut
    • Yeast
    • ▫Wine, beer, bread
    • Mold
    • ▫Cheese, beef
  60. 3 types of food service and what they entail
    • Institutional Food Services
    • ▫Hospitals
    • ▫Nursing Homes
    • ▫Elementary Schools
    • Restaurants
    • ▫Fast Food
    • ▫Full Service
    • Retail Food
    • ▫Deli
    • ▫Meat & Poultry
    • ▫Seafood
    • ▫Produce
  61. Foodborne Illness Risk Factors
    • Food from unsafe sources
    • Inadequate cooking
    • Improper holding temperatures
    • Contaminated equipment
    • Poor personal hygiene
  62. Sanitation in the Home
    • Home needs to be kept clean by periodic cleaning and setting proper rules of conduct
    • 88% of all cases of food poisoning can be traced to handling of food at improper temperatures
  63. Safe zones for cold and hot foods
    • Hot foods: 140-160 degrees
    • Cold foods: 32-40 degrees
    • 165-212: Water boils, heat and reheat foods at these temps
    • 32-0: Water freeze, bacteria survives but does not grow
  64. HACCP
    • Hazard Analysis Critical Control Point
    • Developed in 1971 by US Army Natick Laboratories, the National Aeronautics and Space Administration and the Pillsbury Co
  65. HACCP – 7 Steps
    • 1. Assess potential hazards in all stages of food production
    • -▫Chemical, Physical, Biological
    • 2. Determine critical control points (CCP)
    • -▫Point in the process where controls are necessary to eliminate or reduce hazards
    • 3. Establish requirements to be met at each CCP
    • -▫Based on research data, laws/regulations
    • -▫Be specific, times, temperatures, procedures
    • 4. Establish procedures to monitor each CCP
    • 5. Establish corrective actions
    • -▫What are you going to do when things go wrong
    • 6. Establish record-keeping procedures
    • -▫Hand written/electronic
    • 7. Establish procedures to monitor effectiveness of HACCP (Validation)
    • -▫Laboratory analysis
  66. Regulatory Agencies
    • To determine the wholesomeness and purity of food
    • Protect the consumer from economic fraud and health hazards.
    • Protective legislation is passed and enforced after consumers demand government action
  67. What did "The Jungle" Lead to?
    • The meat inspection act of 1907
    • To prevent adulterated or misbranded meat and meat products from being sold as food and to ensure that meat and meat products are slaughtered and processed under sanitary conditions.
  68. Federal Food and Drug Act of 1906
    To ban interstate commerce in misbranded and adulterated food and drug products
  69. Food, Drug and Cosmetic (FD & C) act
    Provided the government with authority to conduct on-site inspections and provide standards of identity for individual products
  70. Three regulatory agencies have enforcement authority
    • 1- Food and Drug Administration (FDA) (all food except poultry and meat)
    • 2- Meat Inspection Division
    • 3- Poultry Inspection Service
  71. FDA
    • Provides guidance, regulation and oversight
    • -For all foods except meat and poultry
    • -Food Safety, HACCP, retail food production
    • -Food contaminants, labeling and nutrition
    • Science and research (lab procedures)
    • Power to inspect food processing or handling plants and close if needed
    • Can seize and destroy adulterated product
    • Operates under the Federal Food, Drug, and Cosmetic Act (1938)
    • It establishes standards of identity, quality, and fill of containers of food products.
    • It develops and enforces regulations for proper food labeling
  72. Two general regulatory categories:
    • 1.Adulteration
    • 2.Misbranding
    • Easy to determine
    • FDA has a GRASS (Generally Recognized as Safe) list of additives
    • -Which chemicals may be added
    • -How much may be added
    • New additives require approval
    • -Very expensive process
  74. A food is Adultered if:
    • 1- It is filthy, putrid, or decomposed.
    • 2- It is produced under unsanitary conditions.
    • 3- It contains any substance deleterious to health.
  75. A food is misbranded if:
    • It has a standard of identity and fails to meet the standard.
    • It is wrongly labeled It fails to meet the standard for fill of container.
    • Standard of Identity
    • -Can only contain the ingredients specified in thestandard
    • -Misbranded food will be SEIZED AND DESTROYED!!!!!!
    • Can be wrongly labeled as to weight, portions, or ingredients if no standard of identity has been established
    • Theoretically the FDA can only regulate those foods that are shipped between states
  77. The Meat Inspection Bureau
    • A branch of the USDA Agriculture Research Service (ARS)
    • Was established in 1906 through the Federal Meat Inspection Act
    • Slaughter facilities will have inspectors on-site
    • Has a list of approved ingredients for cured and processed products
  78. The Poultry Inspection service
    • Very similar to the Meat Inspection Bureau
    • Was established to ensure that all poultry sold in interstate commerce is wholesome.
  79. What must a food label contain?
    • 1) Basic information
    • 2) List of ingredients
    • 3) Quality grades
    • 4) Nutrition information
    • 5) Shelf life data
  80. Basic information on a food label
    • Name of product
    • Clearly identified
    • Frozen dessert, imitation, chicken stir-fry
    • Net contents
    • Name address of the manufacturer, packer, or distributor
  81. List of Ingredients on a food label
    • All ingredients must be listed
    • Start with major ingredient (by weight)
    • Colors must be listed individually
    • Chemical preservatives common or usual name plus function
    • If a beverage is said to contain juice, the per cent of total juice must be declared on the information panel
  82. Grades on a food label
    • Certifies their level of quality
    • Graded by the USDA (except seafood, USDC)
    • Based on organoleptic criteria, physical and production characteristics
    • Not mandatory, but requested by the producer, distributor etc
    • Meat might be labeled “Prime” or “Choice”
  83. Special Stipulations with food labeling
    • Food packages with less than 12 square inches of space, must provide address or phone number
    • Food packages with less than 40 square inches may present a smaller version of the nutrition information
  84. Exempt with food labeling
    • Food produced by small businesses
    • Food served from immediate consumption
    • RTE foods prepared on site
    • Food shipped for bulk
    • Foods containing no significant amounts of any nutrients
  85. Raw fish, fruits, and vegetables- Raw foods labeling
    • Product name
    • Serving size
    • Calories per serving
    • Amount of protein, total CHO’s, total fat, sodium
    • Vitamins A & C
    • Iron and calcium
  86. Meat and Poultry- Raw foods labeling
    • Product name
    • Service size based on raw or cooked weight
    • Calories per serving
    • Calories from total fat per serving
    • Amount per serving total fat, saturated fat, cholesterol, sodium, total CHO’s, dietary fiber
    • Sugars and protein
    • Iron, calcium, Vit A and C
  87. Health Claims – Allowed Claims
    • Calcium and a reduced risk of osteoporosis
    • Sodium and increased risk of hypertension
    • Fiber and reduced risk of cancer
    • Fruits and vegetables and a reduced risk of cancer
    • Sugar free <0.5 g , reduced sugar <25%
    • Fat free < 0.5g, reduced < 25% , low fat ≤ 3 g
    • Sodium free < 5 mg, reduced/less sodium ≤ 25%
    • High fiber 5 g or more
  88. What is a Food Additive?
    • Chemical substances deliberately added to foods, directly or indirectly in known and regulated quantities
    • Purpose: Assisting in the processing and preservation of foods
    • Purpose: Improvement of flavor, texture, or appearance
  89. GRAS
    Generally Recognized as SafeAdditives that have been used without apparent harm for long periods of time (baking powder, citric acid, salt, sugar)
  90. Delaney Clause
    …. no additive shall be deemed to be safe if it is found to induce cancer when ingested by man or animal, or if it is found, after tests which are appropriate for the evaluation of the safety of food additives, to induce cancer in man or animal
  91. Food Additive Requirements
    • 1.Must perform their intended function
    • 2.Must not deceive the consumer/conceal faulty ingredients
    • 3.Cannot considerably reduce the food’s nutritional value
    • 4.Cannot achieve an effect that could be gained by GMP’s
    • 5.A method of analysis must exist to monitor the use of the additive in foods or its incidental occurrence in foods
  92. Use of Food Additives
    • To improve or maintain nutritional value
    • -▫Enriched or fortified with vitamins or minerals
    • To maintain palatability and wholesomeness
    • -▫Slows spoilage and rancidity
    • To provide leavening or control acidity/alkalinity
    • -▫Rise during baking, flavor, taste, color
    • To enhance flavor or impart desired color
    • -▫Spices, natural and synthetic flavors
  93. Antioxidants
    • Stabilize foods that would loose quality in the presence of oxygen
    • Develops rancidity and discoloration
    • Butylated hydroxyanisole (BHA)
    • Butylated hydroxytoluene (BHT)
  94. Nutrient Additives
    • To aid in a balanced and ample nutrient intake
    • Nutritive loss due to processing conditions
    • Vitamin A, D, and C
  95. Flavorings
    • Natural or synthetic compounds added to produce flavor or modify existing flavors
    • Fruit extracts
    • Amyl acetate (banana flavor)
    • Benzaldehyde (cherry flavor)
  96. Acidulants
    • Lower pH and enhance desired flavors
    • Lower pH inhibits microbial spoilage
    • Vinegar (acetic acid)
    • Citric Acid
    • Lactic Acid
  97. Sweeteners
    • Enhance sweetness of food and beverage products
    • Natural: Fructose, Honey, Maple Sugar
    • Synthetic:Aspartame, Acesulfame K
  98. Leavening Agents
    • Enhance the rising of dough in the manufacture of baked products
    • Baking powder
    • Ammonium and phosphate salts
Card Set
Food Science Test 1
Food Science FSN 230 Test