Nutritional aspects

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Nutritional aspects
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Why do consumers buy fish?

• Tasty
• Convenient
• Good value
• Healthy and nutritious

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Health and seafood

• Seen as healthy option
• Good source of protein
• Low-fat no fat
• Source of the Omega 3 fatty acids
• Oily fish contain n-3 fatty acids (also known as
  omega-3 fatty acids) and vitamins A and D.

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perceptions of health vary with seafood categories
More Healthy

• Less Healthy

Oil rich fish
Shellfish
Fresh
Processed
White fish
Frozen
Natural
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Composition of fish

• Lean fish e.g. Cod
• Water 78 83
• Protein 15 - 20
• Fat 1 - 4

• Fatty fish e.g. Mackerel
• Water 60 - 80
• Protein 16 - 20
• Fat 1 - 24

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Fish muscle
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Cross section through body of fish
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Water

• 70 80 weight of white fish fillet
• 70 of fatty fish fillet

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Protein

• 15 to 20 of body weight
• Amino acids
• lysine
• methionine
• found in high concentrations
• complement cereal protein in diet.

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Fat

• Not distributed evenly throughout the flesh of
  the fish.
• Concentrated in dark muscle of fatty fish.

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Fish oil

• Extracted from whole fish
• High in poly unsaturated fatty acids
• Used for
• Margarines and shortenings

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Fish oil 2

• Extracted from fish liver
• Cod liver oil
• Vitamin A
• Vitamin D
• Omega-3 fatty acids (EPA and DHA).

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The minor components of fish muscle

• Carbohydrates
• Minerals and Vitamins

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Mercury in Fish

• Bad fish, good fish
• Fish most likely to contain mercury
• Shark Swordfish King mackerel Tilefish
  Albacore tuna
• Fish known to be low in mercury
• Shrimp Canned light tuna Salmon Pollock
  Catfish
• Source FDA/EPA

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Factors affecting the composition of fish

• Fishing ground
• Season
• Food supply