Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Intro Microbio > Microbiology of food 1 > Flashcards

Microbiology of food 1 Flashcards

1
Q

lactic acid bacteria is ?

A

Gram positive, aerotolerant anaerobe, rods or cocci

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Homofermentative

A

fermentation yields primarily lactic acid (prickles, saukraut)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Heterofermentative

A

fermentation yields lactivist acid and a variety of flavourful coonhounds ( salami, milk)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

benefits of lactic acid?

A

increases food storage by reducing food spoilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

why pasteurize before fermentation?

A

kill the natural microbiome of the food item

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cheddar

A

lactic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Swiss

A

lactic acid + propionibacteria

propionibacter produce propionic acid and acetic acid (flavour) and Co2 (bubbles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

OKA

A

lactic acid bacteria + Geotrichum

- pressed curd is brined, surface is washed frequently. growth of Geotrichum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Blue, roquefort

A

ripungi is mainly due to penicillium roquefortii
- spores from the mold are mixed with the milk (or curd)
small holes are drilled in the curd before wrapping - the mold grows in the holes and produces spores
- 3-6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Camembert, brie

A
  • unwrapped
    picture of Mold (penicillium) and bacteria ( Brevibacterium)
  • 1-5 months ripening
    Proteases secreted by the microorganisms gives it the softness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

vinegar

A

acetic acid bacteria oxidize ethanol to acetic acid- strict aerobes, THIS IS NOT FERMENTATION
ethanol–> acetaldehyde–> acetic acid
Acetobacter: used in all commercial applications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Wine made from

A

grape must (crushed grapes) + metabisulfite (NA2S2O5) (kills wild yeast)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

white wine vs red wine

A 
white= skin removed
red= skin kept
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

dry vs sweet wine

A

dry= all sugar fermented, sweet= sugar residual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

is yeast added to wine?

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

malting

A

grains that have been germinated, steeped and dried

production of amylase when grains begin to germinate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

mashing

A

Malth is soaked in warm water. during this time the amylase degrades starch–> fermentable sugars. ( glucose and maltose). Mash is then filtered= WORT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

why are hops added?

A

antimicrobial properties, flavour, bitterness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

boiling of wort

A

wort= filtered mash. gets sterile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

S. carlbergensis

A

botton yeast, for a lager, (14-23)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

lager use

A

S. carbergensis yeast (6-12 degrees)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

top yeast=

A

S. cervisiae, for an ale

23
Q

for an ale use

A

s.cervisiae

24
Q

how to make distilled alcoholic beverages?

A

malting, mashing, fermentation, distillation, aging and adding flavour

25
Q

scotch whiskies:

A

malt brew, wort is not boiled, mixed fermentation of lactic acid and yeast

26
Q

are lactic acid gram + or neg?

A

gram +

27
Q

is lactic acid anaerobic or aerobic?

A

areotoleraat anaerobe

28
Q

what shape are lactic acid?

A

rod or cocci

29
Q

Salami

A

mix with salt, sugar , spices and yeast

  • sometimes a scatter lactic acid is added
  • cure: preservation by addition of salt and drying
30
Q

yogurt (what is added?)

A

Streptococcus thermophilic and Lactobacillus bugaris- incubated at 42
Streptococci produce acids which favour the growth of lactobacillus which produces more acid (curdles the milk)

31
Q

2 methods to make Cheeses

A

1) starter culture is added to milk
- ferment the lactose, produce lactic acid
- curd develops
2) rennin can be added to culture which cleaves casein and results in curd forming

32
Q

longer ripening=

A

higher acidity and sharpness

33
Q

S. cerevisiae and S.ellipsoideus are resistant to what? and tolerant to what?

A

NA2S2O5 ( Metabisulfite) and tolerant to 12-14% alcohol

34
Q

Light beer?

A

yeasts and geneticaly manipulated so they can use all the sugar in the wort ( no sugar left over)

35
Q

polishing

A

filtration, carbonation , pasterization ect

36
Q

distilling compared to beer making?

A 
hops not added. distil off the water- ethanol vapour is condensed and then collected. aged. different grains used.
Vodka= wheat, rye, potatoes
Gin= grains
Rum: sugar cane
Brandy= wine
Whiskies= malt brews
37
Q

what is the scobby in kombucha?

A

symbiotic culture of bacteria and yeast

- Acetobacter and Saccharomyces

38
Q

Water activity

A

availability of water

39
Q

Xerophiles

A

dry environment, low osmolarity

40
Q

Osmophiles

A

high osmolarity, high sugar

41
Q

does cold food kill the microorganism

A

no

42
Q

most spoilage microorganisms can grow at a AW as low as

A

0.9

43
Q

less than ___ most bacteria and yeast cannot grow. can molds grow??

A

0.9, yes

44
Q

less than ___ only specialized microogrxs can grow

A

0.8

45
Q

hot food kept above?

cold below?

A

60 degrees

4.5

46
Q

what do swollen packages indicate?

A

CO2 production and aerobic microorganisms

47
Q

natural microorganism in saurqraut

A

leuconostoc mesenteroides

lactobaccilus plantarum

48
Q

microorganisms added to yogurt

A

steptococcus thermophillus

lactobaccillus balgaris

49
Q

some of the ripening is caused by?

A

lactic acid, rennin and other enzymes present

50
Q

which cheese is with lactic acid only

A

cheddar

51
Q

longer ripening =

A

higher acidity and sharpness

52
Q

propionibacteria is involved in the ripening of

A

swiss cheese

53
Q

peniccilum roquforti is involved in the ripening of what cheese?

A

blue cheese

54
Q

penicillium and brevibacteria are spread on the surface of what cheese and are involved in ripening?

A

brie and camambert

Intro Microbio (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions