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Flashcards in Fish2 Deck (34)
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1
Q

Issues for fish farming

A
  • Sustainability
  • Fish escaping
  • Pollution
  • Eco- efficiency
  • Disease
2
Q

Nutritional value of fish

A
  • highly disgestable protein (15- 20g/ 100g of fish)
    [rich in essential amino acid]
    [Protein break down as absorpable peptides, maybe bioactive and enhance immunity]
  • Fish oil ( 20% in oily fish; 1-2 % in lean fish)
    [extracted- long chain omega 3: eicosapentanenoic (EPA) & docosahexaenoic (DHA)]
  • Vitamin A, E, D & B
  • minerals: rich sources of iodine and selenium, low level iron ( but effectively absorpable), calcium and phosphorus (from soft fish bones in salmon, sadines etc)
3
Q

UK fish consumption 2000- 05

A
20% more total fish consumption
100% more shell fish consumption 
25% more oily fish consumption
Consumption below global average (20Kg)
75% in UK do not eat fish
(www.seafish.org)
4
Q

Fish consumed in UK

A

(x1000 T)

  1. Tuna 77000
  2. Salmon 50182
  3. Cod 48775
  4. Prawns 33023
  5. Haddock 23015
5
Q

Fish spoiled quickily if ________, because_______

A

it’s not chilled

continually enzyme activity (autolysis) & bacteria

6
Q

In fish spoilage, protein breaks down to

A

peptide, amino acids and amines - especially cadaverine & histamine

7
Q

Bacteria build up in fish spoilage can

A

produce toxin within the bacteria cell wall (endotoxin)

8
Q

Enzyme in fish optimal activity temperature

A

the typical environmental temperature

9
Q

To reduce enzyme activity in fish

A

to drop the temperature lower than the environmental temperature whether they come from warm or cold water

10
Q

Vitamin A in fish

A

in the form of more assimilated retinol needed for vision, reproduction and development

11
Q

Vitamin D in fish

A

in the form of D3 (cholecalciferol) which promotes absorption of calcium and phosphorus

12
Q

Vitamin E in fish

A

an antioxidant which protects PUFAs and low density cholestrol from oxidation by free radicals

13
Q

Vitamin B complex in fish

A

includes vit B12, thiamine, riboflavin & pyridoxine. Essential in carbohydrate metabolism. B12 needed for formation of red blood cell

14
Q

Shell fish has rich minerals of

A

zinc & iron

15
Q

Lipid content in fish depends on

A
  • types of fish
  • fish feed
  • Time of year
16
Q

Factors of high carcass fat

A
  • low activity in farmed fish

- high energy feed

17
Q

Salmon lipid content

A

vary between 8 - 20%

even higher in bigger fish

18
Q

Fish oil are high in

A
  • long chain omega 3 : eicosapentaenoic acid (EPA) & docosahexaenoic acid (DHA)
  • some monounsaturated and saturated fatty acids
19
Q

fish lipid content reflects on __________

A

fish feed

20
Q

All marine feeds gives high content of

A

EPA eicosapentaenoic acid

DHA docosahexaenoic acid

21
Q

Substitution of fish feed with vegatable oil tend to lower the

A

fish lipid content of eicosapentaenoic and docosahexaenoic, especially the DHA and increase omega 6

22
Q

Demersal fish have ______ lipid content in _______

store lipid in _______

A

eg. cod, haddock
low lipid content in muscle
and store lipid in liver

23
Q

Lipid in muscle are rich in

A

long chain omega 3, with significant amount in phospholipid form

24
Q

Fish oil effects in human

A
  • Brain development
  • Foetus brain growth & development - ME & Central nervous system [ LCPUFA (DHA!!) , iodine & trace elements] [Ratio up to 15:1]
  • Immunity response - eczema, asthma
  • Evolved with littoral marine and lacustrine food chains
  • Poor conversion of linoleic and linolenic acid to LC-PUFAs
  • Placenta selectively transfers LC-PUFAs: biomagnification
25
Q

Role of EPA and DHA

A
  • Produce eicosanoids (cell messengers) in cell membrane, include: prostracyclins and thromboxanes > affecting the contraction of blood vessels and stickiness of platelets; leukotrienes > reduce inflammation
  • reduce thrombosis - blood clot blocks an arteries> avoid stroke
  • reduce irregular heartbeats (arrhythmias)
26
Q

Omega 3 deficiency

A
  • Coronary heart disease and stroke
  • EFA deficiency in infancy and associated retinal and brain damage
  • Auto-immune disorders (e.g. asthma, eczma, psoriasis)
  • Crohn’s disease
  • Mild hypertension
  • Rheumatoid arthritis
27
Q

Fish/Fish Oil and Cardiovascular Protection

A
  • Omega-3 (EPA + DHA) are components of phospholipids in all cell walls throughout the body
  • improve membrane function
  • reduce blood aggregation) > reduce clotting tendency
  • Blood pressure is decreased
  • Three large controlled trials with 32,000 participants showed a 19% to 45% reduction of cardiovascular events as a result of as supplements of EPA plus DHA
  • Epidemiological studies consistently shown a significant inverse relationship between coronary arterial disease (CAD) and fish intake.
  • One fishmeal per week was associated with a 15% reduction in ChD risk, five or more were associated with a 40%

¹(Lee J L et al, 2008)

28
Q

Fish and Brain/Neurological Development

A
  • The brain is the fatty organ containing a high proportion of EPA & DHA, especially DHA
  • Nerves and eyes too have a high content of EPA & DHA
  • Body synthesis of these fatty acids is poor
  • Fish can provide a rich source of the PUFA
  • Human milk contains small amounts of DHA. Fish is recommended, especially in pregnancy and lactation. Foetal development is improved by so doing
  • Continued feeding of some form of fish during infancy improves mental development (cognitive function)
  • Fish reduces incidence of attention deficit hyperactive disorder. It can help in cases of dyslexia
29
Q

Deficiency of omega-3 LC-PUFA linked to:-

A
  • Reduced cognitive function
  • Reduced visual function
  • Attention deficit
  • Hyperactivity disorders
  • Dyslexia
  • Senile dementia
  • Clinical depression
  • Bipolar disorder
  • Schizophrenia
30
Q

Fish Consumption and Mental Development

A
  • can reduce incidence or severity of depression and schizophrenia; also help in some cases of Alzheimer’s disease
  • believed to improve synapase plasticity in the brain, improving neuron connections (signaling)
31
Q

FISH INTAKE AND POST-NATAL DEPRESSION

A

Study of 14,500 pregnant women in last trimester to 8 months after birth

High intakes-consumed fish twice or three times a week

High fish eaters had half the incidence of major depressive disorders

32
Q

FISH FATTY ACIDS MAKE BETTER PRISONERS

A
  • Study at Aylesbury Juvenile Jail, involved 230 prisoners
  • Half received a multi-vitamin supplement plus EPA and DHA; other half got vegetable oil
  • Dramatic reduction in bad behaviour of EPA/DHA consumers

(Bernard Gesch, Oxford University)

33
Q

GLOBAL NEEDS FOR EPA + DHA

A

Global population 7 billion; 1 billion eat fish

Assuming remaining 6 billion should receive EU suggested amount of 250mg/day for normal circulatory, heart and cognitive function > Need 91g / person/ yr

Globally would need 546,000t fish oil or increased fish supply. ( increase over half of now world fish oil production) Is 250 mg/person/day realistic?

34
Q

CLAIMS ALLOWED BY EU FOR BENEFITS OF EPA + DHA

A

DHA:
- Contributes to normal brain function, brain development of foetus and breast-fed infants, vision and visual development of infants to 12 months of age, normal development of eye of foetus and breast-fed infants.

DHA + EPA:
- Contribute to normal function of heart

( EU 432/2012 and 440/2011)