Description of toxic constituents of pulses and their effects.

1. TOXIC
CONSTITUENTS
OF PULSES
Neha
Section-B
A0989216032

2. TOXIC
CONSTITUENTS
Trypsin
Inhibitors
Lathyrogens
Hemagglutinins
Cyanogenic
glycosides
Saponins
Goitrogens

3. TRYPSIN INHIBITORS
 Proteins that inhibit the activity of trypsin.
 Interfere with digestibility of dietary proteins and reduce their utilization.
 Pancreas enlargement and growth retardation occurs in animals by consuming it.
 Release of essential amino acids particular ‘methionine’ is hampered.
 Autoclaving at 120°C for 15-30 minutes inactivates all inhibitors.
 Drastic heat treatment is required for soya bean and kidney bean.

4. LATHYROGENS
 Cause lathyrism, nervous disease that cripples
man.
 Result of excessive consumption of pulse Lathyrus
sativus.
 Affects young men between 15 to 45 years.
Short steps
and jerky
movements
Muscular
stiffness and
stick required.
Muscular
rigidity ,two
sticks required
Inability to
walk , reduced
to crawling

5. LATHYRISM
Neurotoxin responsible
for lathyrism is Beta-N-
Oxalyl-L-alpha, B-
diamino-propionic acid.
Toxin can be removed
by steeping or
parboiling.

6. FAVISM DISEASE
Characterized by hemolytic anemia.
Occurs in individuals who are deficient in
glucose-6-phosphate consume Fava
beans or broad beans.
Three components of broad beans are
responsible.
Germination and boiling reduce these
toxic substances.
Broadbeans
Vicine
Covicine
Dihydroxy
phenyl alanine
DOPA

7. Hemagglutinins
Proteins in nature, also called phyto-agglutinins
or lectins.
Occur widely in leguminous seeds.
Reduce the food intake resulting in poor health.
Lectins interact with di-peptidases,
disaccharides and other enzymes involved in
nutrient digestion and uptake.
Combine with cell linings of intestinal wall and cause impairment in absorption
of amino acids.

8. Cyanogenic glycoside
Yield hydro-cyanic acid upon hydrolysis
by an enzyme present in foodstuff.
This cause Cyanide poisoning by
interfering with tissue respiration.
On hydrolysis of the glycoside of the
enzyme Beta-glucosidase, hydrogen
cyanide is liberated.

9. Saponins
Form lather or foam when shaken with water.
Glycosides of high molecular weight.
Present in soya beans.
Cause nausea and vomiting.
Can be eliminated by soaking prior cooking.
Goitrogens
These substances interfere with iodine
uptake by thyroid gland.
Thiocyanate, isothiocyanates and derivates
are present in soya bean,
groundnuts and lentils.
May lead to precipitation of goiter.

10. Tannins
Tannins are condensed polyphenolic compounds.
Present in high amounts un seed coat and most legumes.
Interfere with iron absorptions.
Interfere with digestive action of trypsin and alpha-amylase.
Also bind proteins and reduce their availability.
Removal of seed coat reduces its content.
Black and red beans have higher content of tannins.
Red kidney beans, black gram, and soya bean have
higher polyphenolic compounds.