fish pt 4 Flashcards
what main species of fish are found in the market?
- cod fish
- salmon
- trout
- tuna
- char
- perch
what are some of the lesser consumed species of fish?
- alaskan pollock
- capelin
- squid
- cunnerfish
- herring
- mackerel
why is Alaskan pollock less appealing for western markets?
flesh is meaty but texture is mushy due to high activity of proteases
why isn’t mackerel a more consumed fish in Canada?
color and smell are not as appealing
how to make surimi
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
what are some applications of surimi?
fish nuggets, imitation seafood products
(fatty/lean) fish are used more for their oil extract
lean fish - they have fat distributed in their skin and liver
how to produce fish oil?
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)
what’s gelatin?
derivative from collagen; collagen molecules are broken down in smaller pieces that are more water soluble
what parts of fish are high in collagen
- skin
- bones
- heads
how do you produce gelatin from fish?
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
what are some uses of fish gelatin?
- replace beef/pork gelatin for people with religious background
- make hydrogels
- candies
- desserts
- coating photographic papers
- food packaging materials
what’s the benefit of harnessing gelatin’s film-forming properties?
better for the environment since they are edible and biodegradable
what useful products can be extracted from shellfish shells?
- carotenoproteins
- chitosan
what are carotenoproteins?
- 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)
how do you extract carotenoproteins?
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
what’s chitosan?
- capable of absorbing moisture and forming hydrogels (like gelatin)
- can be broken down into chitooligosaccharides which have been shown to have choleterol-binding properties
how to produce chitosan?
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
health benefits of fish?
- 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
