Volume 3

  1. Microogranisms are the most important cause for what?
    food spoilage
  2. Gram-positive bacteria keep/do not keep stain?
    keep
  3. What is the major method for bacterial reproduction?
    binary fission
  4. The time laspe from one cell division to the next is called _____?
    generation time
  5. Fungi cannot use the sun for energy...instead fungi secrete digestive enzymes into their environment. What happens next
    this breaks down the organic material and they absorb the resulting nutrients
  6. Molds are fungi consisting of filamentous structures called?
    hyphae.
  7. A good example of mold is the black bread mold_____
    Rhizopus
  8. Reproduction of mold occurs primarily through?
    production of asexual spores
  9. Yeasts are also fungi T/F
    They are multi celled or single celled?
    • Fungi T
    • single celled
  10. Reproduction of yeasts occurs primarily by?
    budding
  11. Yeasts can be helpful such as the process for making?
    wine, leavening bread
  12. What happens during the lag phase?
    microbes do not increase there might even be a slight decrease
  13. During the log phase what happens?
    cells begin rapied cell division
  14. what happens during the stationary phase?
    there is no net increase, meaning the same amount of cells reproduced also die off
  15. what happens during the decline phase?
    cells begin dying because of waste materials and depletion of nutrients
  16. what does pH stand for? What is the range?
    potential hydrogen / 1-14
  17. Values less than 7 are?
    acidic
  18. In general, molds can grow in more acidic conditions than yeasts? T/F
    True
  19. Yeasts can grow at lower pHs than most bacteria? T/F
    True
  20. Bacteria can grow as low as what pH?
    pH 4 and as high as pH 11
  21. Fruits are relatively acidic?
    True
  22. Spoilage of fruits is usually due to?
    molds and yeasts
  23. Meats usually have a pH close to neutral so they are spoiled by____
    bacteria
  24. Explain the fermentation process
    nonharmful bacteria break down carbs in food to lactic acid
  25. what is bound water?
    held by large molecules in the food, therefore cannot be used by microorganisms
  26. What is free water?
    water available to microorganisms for their metabolic activities
  27. fresh fruits and vegetables usually have an aW of?
    .97-.99
  28. dry cereals usually have an aW value of
    .10-.20
  29. Bacteria usually require of a high aW for growth and reproduction...what is that range?
    .96-.99
  30. Halophilic (salt loving) bacteria may grow as low as what aW
    .75
  31. What are the three ways to decrease aW?
    dried/dehydrated, freezing, addiing sugar/salt
  32. Egg whites contain what antimicrobials?
    lysozyme, conalbumin, avidin, and ovomucoid
  33. Milk contains what antimicrobials?
    lysozyme, lactoferrin and lactoperoxidase
  34. Which gram stain bacteria are more affected by suc inhibitors?
    gram positive
  35. Microbial flora refers to what?
    microorganisms found in food
  36. Streptococci in milk may grow in milk and convert lactose/milk sugar into lactic acid...what does this do?
    drops the pH and allows steptococci to grow but inhibits other bacteria
  37. After streptococci reach a high level in milk they inhibit themselves, but allow another bacteria to grow. What is that bacteria?
    Lactobaccilli
  38. Psychrophiles
    Mesophiles
    Thermophiles
    name the temp ranges
    • P- grow at low temp 68- 77
    • M - grow at moderate temp grow best 98 range 68-110
    • T - grow at high temps 113-160
  39. Psychrotroph grows best win?
    low and moderate temps
  40. Second largest cause of food spoilage is?
    enzymes
  41. What are the two types of enzymes?
    food enzymes and microbial enzymes
  42. If the enzyme phospatase is found in milk it means
    the pasteurization for the milk is poor
  43. What causes rancidity?
    hydrolysis or oxidation
  44. Common deteriotative conditions in meat are?
    flavor, odor, texture, or appearance
  45. Flavor conditions in meats include
    rancidity, putrefaction, souring and gassing
  46. Most of the rancidity problems in meats are caused by____
    reaction of oxygen with unsaturated fats or oxidative rancidity
  47. explain putrefaction
    spoilage where bacteria metabolize meat proteins or free amino acids
  48. Where is putrefaction commonly found?
    in canned meats with bacon
  49. Anaerobic bacteria sometimes metabolize carbohydrates in meat products causing ______
    production of organic acids such as lactic acid
  50. Lactic acid in meats creates what?
    sour flavor
  51. Souring gasses are usually found in what meat products?
    fresh meats, bacon, ham, sausage, and canned meats
  52. What are the three types of greening?
    green core, green rings, surface greening
  53. Green cores usually occur in?
    Large sausages such as bologna
  54. Green cores occur only when?
    the meat is cut because the bacteria are aerobic
  55. Cooking meats to an internal temp of____ during processing destroys greening microbes
    160F
  56. How soon is surface greening noticeable?
    5 days after processing and sometimes not until two weeks
  57. Slime is rarely a problem with vaccumm package meats? T/F
    True
  58. What substance is produced in fish once it's killed?
    trimethylamine - because of breakdown in fat or proteins in fish due to enzyme and bacteria (this is what causes the fishy odor
  59. After death, ______in fish is broken down to lactic acid.
    glycogen (lowers pH and preserves fish)
  60. What are the common types of food preservation?
    heat processing, refer/freezing, drying/dehydrating, fermenting, irradiating, controlled atmospheres, and smoking
  61. What is the most used method for heat preservation?
    heat
  62. Agitation allows higher temps to be used during heating without harming the product? T/F
    True
  63. Whats the difference between pastuerization and commercial sterilization?
    pasteruziation is below 100C
  64. List two types of milk pasteruization
    held at 145F for 30 min or flash method 161F for 15 seconds
  65. Blanching is used on _____ ; the process is what?
    fruits and vegetables; foods pass thru water/steam of 190F-212F
  66. What is blanching?
    heat treatment usually applied to fruits and veg...to inactivate natural food enzymes
  67. the best method of food preservation is what?
    refer and freezing - does not effect tast texture nutrition value or other attributes
  68. What is fermenting
    chemical change of anaerobic breakdown of food brought by the use of enzymes or microorganisms
  69. What are the 3 chemical changes made through fermentaion?
    • - acidulation of milk (cultured buttermilk)
    • - oxidation of nitrogenous organic compounds (baker's yeast)
    • - decomposition of starches and sugars into ethyl alcohol, carbon dioxide and organic acids (sausages and pickles)
  70. Which type of food preservation increases nutritional value.
    fermentation...adds riboflavin, B12 and precursor vitamin C
  71. Lactic acid are used to produce what?
    cucumbers into pickles, cabbage into sauerkraut, taro root into Poi. used on meats for salami sausage
  72. Acetic acid bacteria can convert these foods into what?
    wine,, cider, honey and other foods high in sugar into vinegar
  73. what gas is used to ripen bananas?
    ethylene
  74. What are the food additives a food inspector must be aware of?
    curing, dry curing, wet curing, sugar, nitrites/nitrates, sulfur dioxide/sulfites, sorbic acid/sorbates, propionic acid and propionates, benzoic acid/benzoates, ethylene oxide/propylen oxide
  75. what is a wet cure also known as?
    pickled (contains the same ingredients as a dry cure but has been put into a brine or solution)
  76. What is the most common food wet cured?
    meat - hams
  77. What are the characteristics of under curing?
    exhibit a brown or grayish-green
  78. This use belongs to what preservative: added to foods to fix the color, and they only have limited inhibitory use. Most of the time they are mixed with other chemicals for curing foods such as meats
    nitrites and nitrates
  79. This use belongs to what preservative: Used to fix flavor and color of fruits and veg. They have limited inhibitory use against microbes. When dissolving sulfite salts in water, a sulfurous acid is formed that is used to inhibit yeasts, molds, and bacteria. This solution is used mainly in the wine industry as well as for dried fruits and veg
    sulfur dioxed and sulfites
  80. This use belongs to what preservative: _______ is an unsaturated fatty acid used to protect acid foods from mold and yeast growth. This acid is added to such foods as cheese, orange juice, fruit and fruit syrups, margarine, pickles and yogurt
    sorbic acid/sorbates
  81. What are the food packaging materials?
    • rigid metals
    • flexible metals
    • glass
    • plastics
    • cardboard
    • laminates
  82. What is a hermetic container?
    impermeable to or not allowing the entry of gases and vapors. also protects food from moisture gain or loss and is essential for strict vacuum
  83. What is a nonhermetic container?
    also prevents entry of microorganisms, but is permeable to or allows the entry of gases. (cellophane, cardboard)
Author
ctjoyner21
ID
115567
Card Set
Volume 3
Description
Food Tech/San Eval
Updated