????? Spoilage of Foods

1
?????Spoilage of Foods
??????????

• ???
• ????
• M202

2
Do you like?

• Pidan/thousand year-old egg
• Chodofu/stinky bean curd
• Sufu/fermented bean curd
• Blue cheese

3
??

• ???????????blue cheese?????????????
• ???????????

??? ??? ?? blue cheese ?????

4
(No Transcript)
5
????

• ?????????
• ?????????
• ??????????

6
Food Spoilage

• Unacceptable Organoleptic Changes of food
• Tactile
• Visual
• Olfactory
• Flavor

7
Organoleptic Changes
8
??????
9
?????Food Spoilage

• Organoleptic Changes????????
• Tactile ??,????
• Visual ??,??
• Olfactory ??,????
• Flavor ??,????

10
?????

• ??changes,???,??
• ??acceptable,???,??,??
• ??? vs ???
• ??(thousand year egg)

http//www.38sanpachi.com/index1/sub6/p_tan/p_tan.
htm
11
?????

• ????
• ??????
• ?????

12
????

• ?? Oxidation
• Cookies,??,???
• Rancidity
• ??Nonenzymatic Browning reaction
• Maillard reaction
• Condensation of an amino group and a reducing
  compound, resulting complex changes in biological
  and food system.
• Occurs when virtually all foods are heated, and
  also occurs during storage.
• Caramel aromas and golden brown colors, are
  desirable.
• Food darkness and off-flavor development, are
  undesirable.

13
??????

• ???????
• ?????
• ????Enzymatic Browning
• ????

14
Enzymatic Browning
http//www.landfood.ubc.ca/courses/fnh/301/brown/b
rown_prin.htmenzyme
15
?????

• ??
• ??
• ????
• ??

16
???????

• ?????NH3, H2S, Mercaptans(organic sulfide)
• ????CO2, ethanol, methanol, methane, glycerol,
  acetc acid, lactic acid?
• ????fatty acid, glycerol

17
?????????????
18
????????????
19
????????????
20
????

• ??????? ??????
• ??????????????????Mister Donut????,??????????????,
  ???????? (99/9/28)

21
??

• ????????????????