fish pt 4

Question 1

what main species of fish are found in the market?

Answer 1

• cod fish
• salmon
• trout
• tuna
• char
• perch

Question 2

what are some of the lesser consumed species of fish?

Answer 2

• alaskan pollock
• capelin
• squid
• cunnerfish
• herring
• mackerel

Question 3

why is Alaskan pollock less appealing for western markets?

Answer 3

flesh is meaty but texture is mushy due to high activity of proteases

Question 4

why isn’t mackerel a more consumed fish in Canada?

Answer 4

color and smell are not as appealing

Question 5

how to make surimi

Answer 5

1) remove head and viscera
2) wash/clean
3) debone
4) rinse and drain
5) grind the fish w/cryoprotectants and polyphosphates
6) package & freeze for sale/distribution

Question 6

what are some applications of surimi?

Answer 6

fish nuggets, imitation seafood products

Question 7

(fatty/lean) fish are used more for their oil extract

Answer 7

lean fish - they have fat distributed in their skin and liver

Question 8

how to produce fish oil?

Answer 8

1) cook fish to melt fats from rest of fish
2) mechanical pressing/separation to get press liquor and then crude oil
3) water wash the crude oil
4) subject to carbon or activated charcoal (deodorization/decolorization)

Question 9

what’s gelatin?

Answer 9

derivative from collagen; collagen molecules are broken down in smaller pieces that are more water soluble

Question 10

what parts of fish are high in collagen

Answer 10

• skin
• bones
• heads

Question 11

how do you produce gelatin from fish?

Answer 11

1) drying: removes moisture
2) solvent extraction in hexane: removes fat
3) treatment with enzymes (not collagenase): removes proteins
4) demineralize using citric acid, EDTA, lactic acid, or HCL: removes ash –> collagen
5) heat treat and

Question 12

what are some uses of fish gelatin?

Answer 12

• replace beef/pork gelatin for people with religious background
• make hydrogels
• candies
• desserts
• coating photographic papers
• food packaging materials

Question 13

what’s the benefit of harnessing gelatin’s film-forming properties?

Answer 13

better for the environment since they are edible and biodegradable

Question 14

what useful products can be extracted from shellfish shells?

Answer 14

• carotenoproteins

- chitosan

Question 15

what are carotenoproteins?

Answer 15

• used as feed supplement for salmonids.
• cheaper than canthaxanthin/astaxanthin since it’s derived from “waste” product and also provides a source of protein.
• used as colorant for imitation seafood, soups, and other food products (pizzas)

Question 16

how do you extract carotenoproteins?

Answer 16

1) dry, crush into powder
2) demineralize using EDTA, citric acid
3) digest with proteases
4) centrifuge and separate soluble supernatant from insoluble residue
5) take soluble supernatant and dehydrate to concentrate

Question 17

what’s chitosan?

Answer 17

• capable of absorbing moisture and forming hydrogels (like gelatin)
• can be broken down into chitooligosaccharides which have been shown to have choleterol-binding properties

Question 18

how to produce chitosan?

Answer 18

1) dry, crush into powder
2) demineralize using EDTA, citric acid
3) digest with proteases
4) centrifuge and separate soluble supernatant from insoluble residue
5) take the insoluble residue and demineralize
6) decolorize with carbon or activated charcoal –> chitin
7) deacetylation –> chitosan

Question 19

health benefits of fish?

Answer 19

• high quality proteins
• high in omega 3 FAs
• lower in saturated FAs compared to other animal sources
• high in vits B3, B6, and B12
• high in minerals