Toxic Constituents of pulses

1. TOXIC CONSTITUENTS OF
PULSES
BY
Dr.D.Vijayarani
Associate Professor of Home Science
V.V.Vanniaperumal College for Women
Virudhunagar

2. Trypsin inhibitors
 Trypsin inhibators are proteins that inhibit the
activity of trypsin in the gut and interfere with
digestability of dietary proteins and reduce their
utilisation.
 Pancreas enlargement and growth retardation
occur in animals that consume diet containing
trypsin inhibators.
 They are generally heat labile and moist heat
treatment like pressure cooking destroys them.
Autoclaving at 120o C for 15-30 minutes inactivates
almost all trypsin inhibators. These inhibitors
prevent degradation of storage proteins during seed
maturation.

3. Lathyrogens
 Lathryism is a nervous disease that cripples
man. The disease now known to result from an
excessive consumption of the pulse Lathyrus
sativus. It affects young men between the age of
15 to 45 yrs. Lathryus is known by the common
name “Khesari Dal”.
 The dehusked seeds resemble Bengal gram dal
or red gram dal. Hence, sometimes kesari dhal is
used as an adulterant in other dals. The
symptoms of lathyrism are muscular rigidity,
weakness, paralysis of the leg muscle

4. Favism
 Favism is a disease characterised by haemolytic
anaemia that occurs when individuals who are deficient
in glucose – 6 - phosphate dehydrogenase consume
faba beans or broad beans.
 Three different compounds present in faba beans have
been implicated as playing a causative role in the
disease. Two of these are glycosides known as vicine and
covicine and the third is an amino acid derivative known
as dihydroxy phenyl alanine, DOPA.

Germinating and boiling reduce these toxic substances.

5. Haemagglutinins
 These are proteins in nature and sometimes
referred to as phyto agglutinins or lectins.
Haemagglutinins reduce the food intake
resulting in poor growth. Haemagglutinins are
isolated from soya bean, field bean, white bean,
double bean and horse gram. Haemagglutinins
are heat labile.

6. Goitrogens
 These substances interfere with iodine uptake by
thyroid gland. Thiocyanate, isothicyanates and their
derivatives are present in soyabean groundnuts and
lentils.
 Excessive intake of these foods in the face of
marginal intake of iodine from foods and water may
lead to precipitation of goitre.

7. Tannins
 Tannins are condensed polyphenolic
compounds. They are present in high amounts in
seed coat of most legumes.
 Tannins bind with iron irreversibly and interface
with iron absorption. Tannins also bind proteins
are reduced their availability.
 Removal of seed coat of legumes reduces the
tannin content. Removal of husk lowers tannin
content and thus improve the appearance,
texture, cooking quality, palatability,
digestability of the grain and bioavailability of
nutrients.

8.  https://www.slideshare.net/NehaVats3/toxic-
constituents-of-pulses