Fish Nutrition and Feed Technology (2+1)

Unit 5 - Carbohydrates

5.1.Introduction

After the proteins and lipids, the carbohydrates represent the third most abundant group of organic compounds in the animal body. By contrast, carbohydrates constitute the major class of organic nutrients within plant tissues. The carbohydrate group includes important compounds such as glucose, fructose, sucrose, lactose, starch, glycogen, chitin, cellulose etc.

Carbohydrates are usually defined as substances containing carbon, hydrogen and oxygen, with the last two elements being present in the same ratio as in water (ie. C_x(H₂O)_y). Although this definition is satisfactory for the majority of compounds present within this group, a few carbohydrates contain a lower proportion of oxygen than that in water or exist as carbohydrate derivatives which may contain nitrogen and sulphur.