Antinutrients in plants, Phytases, oxalates, lectins .

1. Anti-nutritional Factors
Ajay Prakash Uniyal
Central University of Punjab

2. Introduction
• Compounds that interfere with the absorption
of nutrients.
Phytates
Lectins
Oxalates

3. Phytic acid
• Phytic acid , inositol polyphosphate or phytate is
discovered in 1903.
• It is the principal storage form of phosphorus in
plant tissue, especially bran and seeds.
• Catabolites of phytic acid are called lower inositol
polyphosphates.

4. Structure of phytates
Due to its molecular structure, phytic acid
has affinity to polyvalent cations, such as
minerals and trace elements, and could in
this way interfere with their intestinal
absorption in man and animal.
Source of Phytates
Main source : cereals and legumes, oilseeds and nuts.
In legumes, seed phytates occur predominantly in protein bodies
of endosperm.

5. During the germination of seeds, phytate is hydrolyzed, and
phosphorous along with minerals such as calcium, magnesium and iron
are liberated, becoming available for germination and development of the
seedlings.
There are some beneficial aspects of phytates, despite it has received
status of anti nutrients.
--- Antioxidative effect
--- Preventing pathological calcification e.g. Kidney stones
--- Cholesterol lowering effects
--- Anticancer activity
Inhibitory effects of phytates are low in countries with well balanced
diet but with unbalanced and undernourished diet, it can have serious
effects.
Food processing methods as soaking seeds, addition of phytase etc
ared done to degrade phytate.

6. Lectins
• Lectins are carbohydrate binding proteins
macromolecules that are highly specific for sugar
moeities of other molecules.
• They perform recognition on cellular and molecular
level.
• They mediate attachment and binding of bacteria and
virus to their intended target.
• Lectins are ubiquitous and found majorly in beans and
grains.
• Some lectins as CLEC11A are beneficial while other are
toxic as ricin.

7. Functions of Lectins in Plants
• Rhizoba binding ( lectin knockout transgene studies)
• Plant germination and seed survival growth.
• Recognition of non carbohydrate ligands.
• Many legume seeds have been proven to contain high
lectin activity, termed "hemagglutination.
• Lectin disrupt small intestinal metabolism and damage
intestinal villi by binding with brush border surface of
small intestine.

8. Oxalates
1. Oxalates interfere with calcium absorption.
Oxalates will also crystalize in tissues if
consumed regularly, creating arthritis-like
symptoms and even kidney stones.
2. Source of food : Kale, Spinach, Chard and
other heartly leafy greens.
3. Calcium and magnesium bind to the oxalates
in your stomach and prevent them from being
absorbed.
Oxalates present in plants bind with calcium are practically insoluble

9. Other Anti-nutritional Factors
• Enzymes inhibitors
• Plant enzymes
• Anti-metals
• Anti- vitamins
• Favism factors
• Alkaloids
• Tannins
• Hemaglutinnins

10. Thank You