Leek and shallot 367
Cheops in 2500 BC. Leek was an important vegetable for the Greeks and Romans, and
its use later spread throughout medieval Europe. Leeks have enjoyed a long and rich
history, one that can trace its heritage back through antiquity.
Leeks were valued most by the ancient Egyptians, Greeks and Romans and were
especially revered for their beneficial effect upon the throat. The Greek philosopher
Aristotle credited the clear voice of the partridge to a diet of leeks, while the Roman
emperor Nero supposedly ate leeks every day to make his voice stronger. The Romans
are thought to have introduced leeks to the United Kingdom, where they were able to
flourish because they could withstand cold weather. Leeks have attained an esteemed
status in Wales, where they serve as the country’s national emblem and the Welsh
wear it on St David’s Day. According to legend, Saint David ordered his Welsh
soldiers to identify themselves by wearing the vegetable on their helmets in an
ancient battle against the Saxons that took place in a leek field. Today, leeks are an
important vegetable in many northern European cuisines and are grown in many
European countries (Anon. 2005a).
22.2.2 Chemical composition
The nutritional composition of leek is given in Table 22.1. Compared to onion, leek
contains more proteins and minerals on a fresh weight as well as dry weight basis.
The energy value of 100 g of the edible portion of leek is also higher than that of
onion (van der Meer and Hanelt, 1990). The composition of alliums was reviewed by
Fenwick and Hanley (1990). The major storage tissues of leek are the leaf sheaths,
which are normally 1–2% lower in dry matter (DM) than those of bulb onion; about
11% DM. DM constituents are 70–85% storage carbohydrates (mostly fructans), 10–
20% proteins and about 1% lipids and ash. The flavour compounds in alliums are
sulphur-containing non-protein amino acids, with a common general structure of
cysteine sulphoxide, but with differences in their chemical R groups between the
major allium crops. Besides methyl, leek contains mainly propyl as the R group.
Table 22.1 Chemical composition of leek (per 100 g fresh weight)Constituent ContentWater (g) 90
Protein (g) 2
Fat (g) 0.3
Carbohydrates (g) 5.0
Minerals (g) 1.5
Sodium (mg) 5
Potassium (mg) 250
Calcium (mg) 60
Iron (mg) 1
Phosphorous (mg) 30
Vitamins
b-carotene (mg) 600
Thiamine (B 1 ) 120
Nicotinic acid 500
Pyridoxine (B 6 ) 250
Ascorbic acid (vitamin C) 25Source: van der Meer and Hanelt, 1990.