Fish

1. Fish

2. What is fish? Fish can be classified as followers: Shellfish – crustaceans – have legs & a shell that is joined e.g. crabs, prawns Shellfish – molluscs – have hard outer shell no legs e.g. scallops, cockles Oily fish – contains between 10 – 20% fat in their flesh e.g. mackerel, herring White fish – less than 5% fat in their flesh e.g. haddock, cod, and sole.

3. Fish is not always a favourite food, people thinking it is tasteless, preferring stronger-flavoured foods such as meat or cheese. However: (Using the word bank complete the following) Fish is of great value in the diet because: 1. Its food value is similar to ……………, although weight for ……………… its nutritive value is slightly less: (a) it is a valuable source of complete …………………… (b) it contains ……………………. matter in the form of ………………… - especially fish eaten with ……………. in it, potassium, phosphorus, ……………. and iodine (c) it contains Vitamin B and Vitamins …… and ……, particularly in …………. fish (d) some fish supply …………, either within their own structure or when cooked by …………………

4. How did you do? Fish is of great value in the diet because: 1. Its food value is similar to meat, although weight for weight its nutritive value is slightly less: (a) it is a valuable source of complete protein (b) it contains minerals matter in the form of calcium - especially fish eaten with bones in it, potassium, phosphorus, iron and iodine (c) it contains Vitamin B and Vitamins A & D, particularly in oily fish (d) some fish supply fat, either within their own structure or when cooked by frying

5. Structure Fish is made up of WATER, PROTEIN, FAT & MINERALS The flesh of both white & oily fish are made up of muscle and small amounts of connective tissue Muscle is arranged in segments of short fibres which makes the fish tender & delicate There is no tough elastin in fish, so the flesh should always be tender

6. Effects of Cooking During cooking, the fish muscle segments shrink & moisture is squeezed out. This is why moderate temperatures & quick methods are best. During the cooking process the connective tissue weakens & dissolves. In oily fish, the fat content keeps the flesh moist Use any left over cooking liquid in a sauce to replace moisture The flesh starts to denature (become cooked) at 60°C

7. How fresh is your fish? Fresh fish has • Moist, firm flesh • Bright red gills and bright clear eyes • Bright shiny scales which are firmly attached to the skin • A fresh smell Smoked and salted fish should have • Firm flesh and a shiny skin • A good “smoky” smell All shellfish must • Have tightly closed shells • Smell fresh with no hint of an “ammonia” smell • Lobsters, crabs and prawns must have shells that a bright & hard Fish of all types spoil rapidly so should ideally be eaten on the day it is bought

8. Preserving Fish Fish start to deteriorate as soon as they are caught. Most fish are put on ice or frozen to halt this process Fish can be Frozen – usually done immediately after the fish leave the nets on board the boats Smokingthis gives a characteristic odour and flavour to the fish, e.g. smoked mackerel. Canned (in brine, oil or a sauce). Canned fish provides good amounts of calcium as the process softens the fish bones enabling the consumer to eat them Salting is a traditional method of preserving fish; still commonly used today in some parts of the world, e.g. salt cod. Pickled in vinegar (e.g. pickled herrings & roll mops) Marinating: adding salt and/or acid (e.g. lemon juice or vinegar) can improve the flavour of the fish and increase its shelf life Drying: sun drying is traditional in many warm areas of the world.

9. Disadvantages of freezing fish Ice crystals form in the flesh and damage the fibres Protein changes when moisture is lost, on thawing the fish maybe tough and stringy

10. Complete the following statements using the word bank • The flavour of fish is more delicate than that of meat as it contains fewer ………………………… • A commonly used example of white fish is …………………………………… • A popular oily fish is ……………………………………… • One lesser-used shellfish is …………………………………… • A fish which is usually eaten raw is ……………………………… • When cooked, the flesh of fish flakes separate due to the absence of ………………………… in the connective tissue. • The ……………………………… quickly dissolves, and this increases the digestibility of fish. • An important mineral present in fish and lacking in meat is ………………… • The eggs of fish , which are often eaten are known as …………… • In order to make shellfish fibres more easily digestible, it is often eaten with …………………… Max. 10 marks

11. Classification of fish 21 marks

12. Complete remaining questions on the worksheet

13. How did you do? • The flavour of fish is more delicate than that of meat as it contains fewer EXTRACTIVES • A commonly used example of white fish is HAKE • A popular oily fish is PILCHARD • One lesser-used shellfish is CRAYFISH • A fish which is usually eaten raw is OYSTERS • When cooked, the flesh of fish flakes separate due to the absence of ELASTIN in the connective tissue. • The GELATINE quickly dissolves, and this increases the digestibility of fish. • An important mineral present in fish and lacking in meat is IODINE • The eggs of fish , which are often eaten are known as ROE • In order to make shellfish fibres more easily digestible, it is often eaten with VINEGAR Max. 10 marks

14. Classification of fish 21 marks