chapter  9
Fatty Acids
Pages 54

Rosario Zamora and Francisco J. Hidalgo Instituto de la Grasa, CSIC, Seville, Spain

I. INTRODUCTION

Lipids consist of a broad group of compounds that are

generally soluble in organic solvents but only sparingly

soluble in water. They are major constituents of

adipose tissue, and together with proteins and carbo-

hydrates, they constitute the principal structural com-

ponents of all living cells. Glycerol esters of fatty acids,

which account for about 98% of the lipids in our

foods and over 90% of the fat in the body, have

been traditionally called fats and oils, based solely

on whether the material is solid or liquid at room

temperature (1-4). Food lipids are either consumed in the form of

isolated fats or as constituents of basic foods.

Worldwide, food lipids’ intake varies considerably

from some countries to others. In general, the con-

sumption of food lipids increases with increasing per

capita income. Thus, in developing countries food

lipids’ intake is, and has been for many generations,

10 to 20% of the energy intake, while in developed

countries dietary food lipids’ intake ranges from 35 to

45% of the total energy intake (5-8). Fatty acids are key components of lipids. They are

the aliphatic monocarboxylic acids that can be liber-

ated by hydrolysis from naturally occurring fats.

Although more than 1000 acids have been identified,

the number occurring frequently in most common

lipids is much fewer than this and most food analysts

will probably encounter not more than a few tens of

different acids.