Brainscape's Knowledge GenomeTM

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


See full index

food commodities > Fish and Shellfish > Flashcards

Fish and Shellfish Flashcards

You may prefer our related Brainscape-certified flashcards:
Gourmet Food flashcards
1
Q

What is seafood?

A

aquatic animals for human consumption

true fish + shellfish

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

What are the commonly marketed fish products? (6)

A 
Fresh
Frozen
Smoked/salted/marinated
Canned
Fish Meal
Fish Oil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The top fish producing country is:

A

China

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

What are the various animal types harvested for seafood?

A 
vertebrates:
- bony fish
- cartilagenous fish (shark, skate)
invertebrates:
- mollusc
- crustacean
- echinoderms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the flavor classifications of fish? give some examples

A

Mild: Cod, Halibut, Porgie
Medium: Shrimp, Lobster, Skate
Strong: Salmon, Mackerel, Sardines

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

What are the factors that affect fish composition? (8)

A
  • species
  • diet
  • season
  • age
  • sex
  • habitat
  • population density
  • migratory or spawning behaviour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Most fish sold as food is in ____ form, followed by _____.

A

frozen (24%); fresh (22%)

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

Wild harvest of fish was increasing, but now has stabilized around ___. Why?

What source of fish in increasing?

A

95 tonnes

  • Regulations (government limit)
  • Depletion of stocks (overfished, few left)

Aquaculture (farmed fish) is increasing

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

What are some non-food uses of fish? (5)

A 
Fertilizer
Feed
Supplements
Gelatin (glue)
Cosmetics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name the fins on a teleost fish:

A

on back: Dorsal, Adipose (near tail)
Tail: Caudal
Belly: Pectoral (front), Pelvic, Anal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does fat distribution differ in fatty and lean fish? What types of lipid predominate?

A

fatty: fat throughout flesh
lean: fat accumulates in liver/gut

mostly TG, also PL in skin and membranes

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

fish is about ___% protein, which is comparable to ____.

A

16-21%

beef

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

What component shows the most variation in fish? What other component will also vary, and what causes these variations?

A

Lipids, also protein
spawning/migration -> use energy, lower lipid/protein
increase in period of heavy feeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the 2 layers of fish skin:

A 
outer layer: epidermis
- high moisture
- glands make mucus (MUCOPOLYSACCARIDES)
inner layer: dermis
- scales
- conn tissue fibres
- pigment cells (GUANOPHORES)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The main sugars of mucopolysaccharides that form the fish slime layer are: (2)

A

glucosamine, galactosamine

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

Fish oil is an excellent source of ____ PUFAs, but what problem does this cause?

A 
omega 3 (good for health!)
prone to oxidative rancidity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the main cause for the rapid bacterial decay of fish?

A

The microflora present on scales/skin, resistant to low temperatures

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

Name the 3 protein types in fish, and their proportions.

A

Sarcoplasmic (dissolved) - 20-30%
Myofibrillar (muscle, salt-soluble): 65-75%
Stromal (insoluble) : 3-10%

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

actin, myosin, and troponin are all ____ proteins, while collagen is a ____ protein.

A

myofibrillar

stromal

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

how do the proportions of fish protein types compare to that in mammals?
How does this affect the fish meat?

A

Less stromal: don’t need as much connective tissue since water can support weight

More myofibrillar: need strong muscle for swimming

sarcoplasmic stays the same (enzymes, etc)

fish is more tender than meat, since less sarcoplasmic

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

What type of protein is Mb?

A

sarcoplasmic

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

How do fish myofibrillar proteins compare to mammalian counterparts?

A

more myofibrillar, but individual proteins in same proportion
More easily denatured by heat
Fast hydrolysis
(easy digestibility)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

True/False: the sarcoplasmic protein proportions and types remain fairly constant among all fish.

A

False: different patterns can be seen, and used to identify fish

24
Q

What sarcoplasmic fish protein is different from the mammal version? This protein is concentrated in ______.

A

Mb - fish has cysteine, mammal does not

concentrated in dark muscle

25
Q

Fish protein generally has higher levels of what AAs, compared to mammals? This means that it would pair well with:

A

lysine, cysteine, methionine

cereals (low in those AAs)

26
Q

___, a very basic non-protein AA, is found in fish and has antimicrobial properties

A

protamine

27
Q

The main connective tissue proteins in fish are:

A

collagen (90%), elastin

28
Q

How does the final meat yield from fish compare to mammals?

A

lower yield after removal of head, guts, tail, etc (lose up to 50%)
mollusc/crustacea lose even more (over 50%)
but less losses during cooking

29
Q

True/False: fish contain all the essential AAs.

A

True (like all animal protein)

30
Q

What are the major NPNs found in fish? (6)

A

N containing extractives:

  • volatile bases (TMAO, NH3)
  • urea (cartilagenous fish)
  • nucleotides/purines
  • free AA
  • creatine
31
Q

Fish are a good source of what vitamins and minerals?

A

vitamins: B (multiple), D and A (fatty fish)
minerals: Na, K, Mg, Fe, I (saltwater), Se, Cu, Ca, P

32
Q

What are some non protein AA found in fish? (4)

A

betaine, carnosine, anserine, protamine

33
Q

TMAO is naturally present in fish for what purpose? What happens after harvest?

A

trimethylamineoxide - help fish stay afloat (osmolyte)

TMAO reduced (lose H2) -> TMA -> (dehydrogenase) -> DMA + formaldehyde

TMA has fishy odor (bad)
formaldehyde will cross link proteins -> tougher texture

34
Q

_____ fish contain some urea content

A

cartilagenous

35
Q

What are the various nucleotides? (5)

A

ATP, CTP, UTP, TTP, GTP

36
Q

breakdown of ___ yields IMP, which is (good/bad). Why?

A

ATP; good (enhance flavor, indicates freshness)

37
Q

___ is produced from AA catabolism, its presence in fish indicates poor quality

A

urea

38
Q

How would continued breakdown of ATP produce unwanted compounds? Describe the process

A

ATP -> ADP -> AMP -> adenosine + IMP (good, enhance flavor)

IMP -> hypoxanthine -> xanthin -> uric acid/urea
hypoxanthine, xanthin, urea will cause off taste, quality loss

39
Q

What are the carbohydrate sources in fish? (2)

A

glycogen in muscle

polysaccharides in slime layer

40
Q

Fish contains (more/less) glycogen than mammals.

A

less; need lot of energy for swimming so less is stored

41
Q

What is the “lateral line”

A

horizontal row of scales down fish body - can use to sense changes in surroundings/movement

42
Q

Describe the process of bringing wild fish to market (8)

A
  1. catch
  2. hold (store live in tanks, since long time at sea)
    (can use tranquilizer to slow - Aqui-S)
  3. sort (remove bycatch, too small fish)
  4. bleed/gut - remove head/guts/blood
  5. clean/wash - remove pigments and gut residue (contamination)
  6. ice/chill
  7. storage
  8. market
43
Q

What are the grades of fish? What are some factors it is based on, and what 2 factors do not affect grade?

A

Premium, A, B, C
color of eyes/gills, state of fins/skin/body, odor, if it has been bled/chilled

does not depend on flesh color, or skin color (varies with species and feed)

44
Q

What problems can occur with evisceration? (3)

A

blood pigments will discolor fish
gut bacteria cause contamination
proteases/lipases cause degradation

45
Q

What are some uses for undesirable fish? (2)

A 
Mild fish (pollock, carcasses, etc) -> surimi
strong fish (mackerel, herring) -> fish oil
46
Q

What is surimi? How is surimi produced?

A

nutrient dense fish paste

take mild fish -> gut/bleed/clean -> debone -> leach -> strain -> mix with CRYOPROTECTANTS (preserve texture) -> pack in frozen storage

47
Q

How is fish oil obtained?

A

cook fatty fish -> press to remove liquid -> separate liquor into water and CRUDE OIL -> water wash + C to remove odors/pigment -> fish oil

48
Q

What is the lipid composition of fish oil? What are its uses (5)?

A

PUFAs: 40%
MUFAs: 30%
SFAs: 30%

health: PUFAs prevent cardiovasc disease, important for growing brain
cosmetics
fuel
plant protective coatings
paint
49
Q

What are two compounds in crustacean waste that can be repurposed?

A

carotenoproteins - coloring - as additive or for salmon feed

chitosan/chitin - films, plastics, thickeners, etc

50
Q

How is chitosan obtained?

A

crush -> demineralize (chelator) -> proteolysis (protease) -> centrifuge

dry the residue: and repeat previous steps to purify -> decolorize with acetone, HClO2, or peroxide -> CHITIN -> remove acetyl group -> CHITOSAN

51
Q

Fish gelatin is in ___ form, so it is easy to work with, and acts as a ____ or _____. What are some non food uses?

A

liquid; stabilizer; thickener

can use for pharmaceuticals, glue, films

52
Q

Describe the process of fish skin gelatin production

A

remove oil for other uses, then dry with mild heat to not damage protein
solvent extraction to completely defat
Use NaOH and Trypsin to destroy non-collagen protein
Use chelator (citric acid) to remove minerals
hydrolyze collagen with pepsin or other protease
gelatin

53
Q

Describe the process of fish skin gelatin production

A

remove oil for other uses, then dry with mild heat to not damage protein
solvent extraction to completely defat
Use NaOH and Trypsin to destroy non-collagen protein
Use chelator (citric acid) to remove minerals
hydrolyze collagen with pepsin or other protease
gelatin

54
Q

How are carotenoproteins extracted from crustacean shells?

A

take supernatant (liquid) after chitin removal, then dry

55
Q

What is the difference between chitosan and chitin?

A

Chitin has acetyl group, insoluble white powder.

convert to chitosan to make soluble in dilute mineral acid.

food commodities (5 decks)

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