Understanding Ingredients Fish Topics Types of Fish Structures

Understanding Ingredients Fish

Topics • Types of Fish • Structures of Fish • Nutritive Value of Fish • Choice and Storage of Fish • Uses of Fish in Cooking / Diet 2

Types of Fish 3

Types of Fish • Fish is both edible finfish and shellfish obtained from marine and fresh water sources • Fish is softer and flakier than either mammals or poultry, because muscle fibers exist as short bundles, which contain thin layers of connective tissue • There are many ways to classify fish, e. g. to group them according to their place of living and their fat content 4

Types of Fish Groups of finfish according to their place of living: Sea Fish Lives in the sea and ocean • • • Grouper Sole Mackerel Pomfret Golden thread Freshwater Fish Lives in rivers, lakes and ponds • • Carp Catfish Grass carp Grey mullet 5

Types of Fish Groups of finfish according to their fat content: Oily Fish White Fish Flesh of oily fish is often darker than that of white fish, flesh contains fat Flesh of white fish is white, it contains very little fat • • • Cod Freshwater goby Dace Sole Grouper • • • Mackerel Salmon Catfish Grass carp Carp 6

Types of Fish • Shellfish has a hard shell. It is often grouped into two main types • • Crustaceans With an outer shell and leg Mollusks With an outer shell(s), without leg Crab Crayfish Lobster Shrimp • • • Abalone Clams Mussels Oysters Scallops 7

Types of Fish Configuration of fish available in the market: • Whole fish • Fillet • Cutlet • Steak 8

Types of Fish Processed fish and fish products available in the market: • Canned fish – Sardine, tuna, salmon, dace • Smoked fish – Salmon • Preserved fish and their products – Salted fish, salted anchovy in oil, shrimp paste, oyster sauce • Dehydrated fish – Dried shrimp, dried oyster • Processed fish – Fish balls, surimi 9

Structure of Fish 10

Structure of Fish • The muscle fibres of fish are similar to those of meat • The fibres are arranged in flat flakes rather than in bundles • There is only one type of connective tissue – collagen, it softens and dissolves in cooking • When fish is cooked, the flakes separate easily from each other and from the bone 11

Nutritive Value of Fish 12

Nutritive Value of Fish Protein • The muscle fibres are composed of protein • There is little difference between the different types of fish • Both fish and shellfish are good sources of high biological value protein 13

Nutritive Value of Fish Fat • Fish oils give a strong smell and taste • The fat content is affected by the: – type of fish • white fish have no fat in the flesh, fat is only in the liver • oily fish contain oil in the flesh – method of cooking – method of processing • Fat content in shellfish is quite low 14

Nutritive Value of Fish Cholesterol • Cholesterol in some shellfish is low (e. g. scallop), other is high (e. g. clam and mussel) • Cholesterol in some shellfish (e. g. shrimp, crab, lobster) is mainly concentrated in the roe and head • Both fish and shellfish are lower in saturated fat than other meats Carbohydrates • Similar to mammals, carbohydrates is negligible in fish tissue 15

Nutritive Value of Fish Vitamins • Oily fish is a good source of vitamins A and D • White fish livers are not usually served and thus the vitamin is lost 16

Nutritive Value of Fish Minerals • The muscle fibres of fish also contain minerals such as calcium, phosphorous, and iodine • Calcium is present in canned fish where the bones have been processed to become soft and crumbly and can be eaten • Salt (sodium chloride) is found in the flesh of seawater fish, it is also added during processing • The mineral content of shellfish varies, e. g. – – Crabs and mussels are rich in calcium Clams and oysters are rich in iron Oysters are rich in zinc All types of shellfish are rich in iodine and phosphorous 17

Choice and Storage of Fish 18

Choosing Fish Fresh finfish should have the following features: • Bright, shiny and plentiful scales • Clear and bulging eyes • Bright red gills • Firm and springy flesh 19

Choosing Fish Live shellfish should have the following features: • Active and full of movements • Crabs and lobsters should feel heavy in weight, crabs should not be watery when opened • Prawns and shrimps should have clear but not blackened shells, the heads should be firmly attached to the bodies • Single shellfish without legs should have tightly closed shells • Do not buy shellfish which has an unpleasant smell 20

Storing Fish Fresh finfish Frozen finfish Canned fish • Cook and eat the fish on the day it is bought • If it is to be kept for 2 to 3 days, remove the internal organs, clean the fish thoroughly, put it in a polythene bag and store it in the refrigerator. • Keep in the freezer • Never refreeze thawed fish • Keep in a dry cupboard 21

Storing Fish Fresh shellfish • Wrap and store in the refrigerator • Cook and eat the fish on the day it is bought Frozen shellfish • Store fresh shrimps and prawns in polythene bag • Keep in the freezer • Never refreeze thawed shellfish 22

Uses of Fish in Cooking / Diet 23

Uses of Fish in Cooking / Diet • Fish may be steamed, boiled, grilled, baked or fried • Fish can be used as an ingredient in soups, main courses, snacks • Examples of fish-based dishes: – Shrimp on Toast – Fish Cakes – Fish Balls – Fish burger – Fish pie 24

References • Provost, J. , Kelly, B. , Bodwin, J. , & Wallert, M. (2016). The Science of Cooking. John Wiley & Sons. • Vickie A. Vaclavik, Elizabeth W. Christian. Essentials of food science. New York, NY: Springer, c 2008. 25