The presentation shares the information about the major antinutritional factors found in legume crops and the methods to overcome or minimize their effect in diet through various ways.

1. ANTINUTRIONAL FACTORS IN PULSES
AND METHODS TO OVERCOME
GPB 608 Breeding pulses and Oil seed
Crops (3+1)
Submitted by
Ananda lekshmi .L
2018600801

2.  Defined as a chemical substance, which, when present in
human or animal food, impairs growth and normal
functioning of the body.
 Anti-nutritional factors mainly occur in pulses and grain
legumes and foods and feed material prepared from grain
legumes and pulses.
 Anti-nutritional factors can cause detrimental effects to
human and animal growth and performance by impairing
intake, uptake, or utilization of other food and feed
components, or by causing discomfort and stress to
human and animals.
Anti Nutritional Factors

3.  A substance which when present in human or animal feed
interferes with assimilation of certain nutrients showing toxic or
undesirable physiological effects, such as flatulence.
 Nevertheless such ANFs provide a protective role against insects,
predators and pathogens attacks.
 These compounds range in effect from relatively inoffensive
polyphenols to the relatively harmful protease inhibitors.
 grain legumes with comparably large and protein-rich seed which
often contain substantial amounts of "anti-nutritive" factors (ANF),

4.  Lectins
 Tanins
 Protease inhibitors
 Phytic acid
 Lathyrogen
 Saponin
 oligosacchride
Antinutritional factors in pulses:

5.  Lectins are proteinaceous in nature and commonly found in some of
the beans.
 Seeds of some of the edible species of pulses such as lentil and pea
also contain phytohemagglutinins.
 These are proteins which possess a specific affinity for certain
sugar molecules.
 Most of the lectins contain 4 to 10% carbohydrates.
 The lectins from mungbean are non toxic, whereas the lectins
obtained from immature seeds of pigeon pea and ricebean are
harmful (De-Muelenaere, 1965, Ikegwuonu and Bassir, 1977,
Manage et al., 1972).
LECTINS:

6.  Lectins reduce the bioavailability of nutrients, which is due to
direct action of lectin on digestive enzymes (Jindel et al.,
1982, Rea et al., 1985).
 Preliminary soaking prior to autoclaving or cooking is
required for complete elimination of the toxicity of lectins
(Liener, 1976, Kute et al., 1984).
 deleterious effects associated with lectins are food poisoning,
vomiting, bloating, and diarrhoea in humans .

7.  Tannin (Polyphenol) is known to form complexes with proteins
under certain pH conditions.
 Tannins-protein complexes are reported to be responsible for low
protein digestibility, decreased amino acid availability and increased
fecal nitrogen.
 Among pulses, pigeonpea, urdbean and pea have highest tannins in
seeds.
 It appears that tannins content in pulses varies with colour of the
seed coat.
 Lower amount of tannins, in general are observed in light coloured
seeds than brown dark coloured pulses.
 White seeded varieties of Phaseolus vulgaris are contain almost
negligible tannins, while coloured varieties contain large quantities
of tannins (Deshpande et al., 1982, Deshpande and Cheryan, 1983).
TANNINS:

8. Single gene mutation has a pleiotropic effect eliminating tannins from
seed coat and determining a white flower trait in pea and faba bean.
Zero-tannin trait in lentil is controlled by a single recessive gene (tan)

9.  The tannins content in beans changes during seed maturation
(Kadam et al., 1982).
 Tannins are mainly located in seed coat of pulses, hence physical
removal of seed coat by either dehulling or milling and separating
hulls decreases the tannin content of pulses and improves their
nutritional quality.
 Dehulling eliminates about 68 to 99% of tannins in seed.
 Soaking of seeds before cooking is a common household practice
and, used to soften the texture and hasten the process of cooking.
 Leaching of tannins increases with the time of soaking in distilled
water.

10.  Raising the period of soaking from 6 to 12 and 18 hrs further
reduces tannin content of seed
 Cooking and discarding the cooking water results in about 37.5 to
77% decrease in tannin content of seeds (Reddy et al., (1985).
 Overnight soaking in water and subsequent germination for 48
hrs removes more than 50% of the tannins in pigeonpea,
chickpea, mungbean and urdbean (Jood et al., 1987, Kataria et
al., 1989

11.  Trypsin inhibitors belong to a broad class of proteins (protease
inhibitors) that inhibit proteolytic enzymes.
 Trypsin inhibitor activity increases as seed maturation progresses
(Kute et al., 1984).
 Most of the plant protease inhibitors are destroyed by heat resulting
in enhancement of nutritive value of protein (Liener, 1962).
 The moisture content, time, temperature and pressure are the major
factors that influence cooking rates, inactivation of the trypsin
inhibitor, and subsequent increase in nutritive value.
 Moist heat has been shown to be effective in destroying trypsin
inhibitor activity in pulses (Rackis, 1981).
Protease inhibitors:

12.  Germination also influences the trypsin inhibitors activity (Hobday
et al., 1973, Kadam et al., 1986).
 The application of dry heat to the seeds and meal is not effective in
inactivating the trypsin inhibitor and chymotrypsin inhibitory
activity of pigeon pea, but soaking for 24 hrs followed by cooking
for 20 min is effective in destroying trypsin activity
(Mulimani and Paramjyothi, 1994).

13.  Phytic acid is another antinutritional factor and is a major storage
form of phosphorus in plants (60-90% of total seed phosphorus).
 It is ubiquitous in seed comprising 1-3% of all nuts, cereals,
legumes and oil seeds.
 It is present as crystals inside protein bodies in discrete regions of
seeds.
 Phytic acid is considered as one of the antinutrients mainly due to
its ability to bind to essential dietary minerals as well as proteins
and starch, consequently reducing their bioavailability in humans.
Phytic acid:

14.  However, on food processing, phytates can be
dephosphorylated to produce degradation products
 roasting and autoclaving has been reported to decrease
phytic acid in dry bean .

15.  Seeds of V. faba can trigger the onset of Favism, an acute
haemolytic disease which affects individuals lacking sufficient
activity of the NADPH producing enzyme glucose-6-P-
dehydrogenase (G6PD) in their red blood cells.
(Mager et al., 1980; Marquardt,1989)
 The glycosides vicine and convicine (VC) are concentrated in
cotyledons of faba bean seeds.
 Conventional cultivars contain from 6 to 14 g/kg of VC in mature
seed
 A mutant allele vc has been discovered which reduces 10 to 20
fold VC content. (Duc et al. 1989).
 This allele has a positive effects on egg production by laying hen
and energy value of feeds for chicken
Vicine and convicine

16.  Lathyrogen toxin is one of the natural toxins found in the seeds of
lathyrus, commonly known as khesari or teora, which is known to
cause lathyrism.
 If consumed in excess quantity for long time, it causes paralysis in
the legs in susceptible individuals and is believed to be caused by a
toxic amino acid known as N-Oxalyl amino alanine (BOAA).
 The BOAA content of seed of lathyrus varies from 0.05 to 0.4%
(Srivastava et al., (2000).
 Less than 0.2% BOAA is considered safer from health point of
view (Siddiqu, 1995).
 The concentration of BOAA is maximum in the germ portion of the
seed of lathyrus; therefore the degerming of the seed cotyledons
greatly reduces the neurotoxin content of lathyrus seed .
Lathyrogen:

17.  Processing techniques like soaking, parboiling,
roasting and degerming eliminates neurotoxin to a
large extent.
 Pre-cooking soaking of pulse removes 30-40% of
toxin (Srivastava and Srivastava, 2002).
 Roasting of seeds for about 15-20 min removes
most of the toxin of lathyrus (Rao et al., 1969).
 Preboiling of lathyrus seeds removes more than 80%
of the toxin and produces minimum change in
nutritive value (Nagrajan et al., 1965).

18.  Saponins are secondary plant metabolites present in pulses.
 The chickpea, mungbean and pigeonpea contain saponins ranging
from 0.05 to 0.23%.
 Though saponin reduces the nutritive value of pulses, but the
saponins appear to be beneficial as they are responsible for lowering
the cholesterol in body and may be important in human nutrition in
reducing the risk of heart diseases and also inhibited colon cancer.
 Processing techniques like soaking, germination and cooking helps in
reducing the saponin contents of pulses.
Saponins:

19.  Soaking of pulses reduces 5 to 20% saponin in pulse.
 Germination reduces saponin content of various pulses. Forty eight hours
sprouting results in 22% reduction of saponin in urdbean (Jood et al., 1988,
Kataria and Chauhan, 1988).
 The loss of saponin increases with increase in the germination period.
 Cooking also reduces saponin content of seed/ grain in chickpea,
mungbean and urdbean (Jood et al., 1987, Kataria et al., 1989, Sharma and
Sehgal, 1992),

20.  Ingestion of large quantities of pulses is known to cause flatulence
in human beings.
 Accumulation of flatus in the intestinal tract results in discomfort,
abdominal rumblings, cramps, pain, diarrhoea etc.
 The oligosaccharides of the raffinose family sugars viz., raffinose,
stachyose and verbascose from pulses are causative agent of
flatulance in humans (Rao, and Belvady, 1978).
 Raffinose is not digested by man because the intestinal mucosa
lacks the hydrolytic enzyme a1, 6-galactosidase (Cristotaro and
Wuhrmann, 1974).
Oligosaccharides:

21.  Microflora in the lower intestinal tract metabolise these
oligosaccharides and produce large amount of carbon dioxide,
hydrogen and small quantity of methane, which causes flatus
production (Rackis, 1974).
 Varieties with low raffinose sugars can be developed and also be
used for reducing the oligosaccharides, which are removed as a
result of soaking (Iyenger and Kulkarni, 1977).
 Discarding cooking water also reduces the raffinose contents in
beans (Reddy and Salunkhe, 1980).
 Raffinose sugars can also be removed from pulses by germination
(Gupta and Wagle, 1980, Rao and Belvady, 1978).

22.  There can be no doubt that the so called "anti-nutrients" of legumes
have a biological function.
 They are certainly important in the physiology of seedlings as N or
C storage compounds and to facilitate nutrient uptake and
rhizosphere establishment.
 Since they are also toxic to animals and sometimes even to
microorganisms, viruses and other plants, they exhibit defence
functions at the same time.
Can "anti-nutrients" be even useful?

23. Anti nutritional factors play important role in
 Seed germination
 Preservation of seed longevity
 Desiccation tolerance
 Stored carbon reserves in seeds will be released during seed
germination. ---polysaccharides, sugars, oil and proteins
 Dessication tolerance in legumes could be the result of
antinutritional factors protecting membrane-bound proteins

24.  An important question arising in the context of selection for low-
toxin lines is whether the genetic reduction of anti-feedant and anti-
nutritional factors is going to have a negative effect on the
ecological fitness of the resulting cultivars?
 In the words of Bell (1977) who reviewed the ecological function of
non-protein amino acids, "The development of a toxin-free crop
would be totally impractical if the reduction in toxicity to man or
domestic animals was accompanied by an equal or greater reduction
in toxicity to predatory insects which might destroy the crop before
it could be harvested".

25.  the selection of genotypes with low levels of ANF factors, thus
enabling the development of more palatable and less toxic cultivars.
 The general aim is a selection of non-toxic and palatable genotypes
requiring efficient screening techniques to expedite the quantitative
detection of individual ANFs for the selection of improved grain
legume cultivars.
 Sometimes simple colour reagents might work for an initial test,
such as Reifers reagent for quinolizidine alkaloids in lupins (it
produces a brown precipitate with alkaloids; Wink, 1993).
Elimination of ANFs through genetic
modification

26.  Immunological methods such as ELISA to detect specific proteins
can also be established for low molecular weight compounds such
as alkaloids (Wink 1993).
 Living systems can also be useful for selection: Whereas alkaloid
rich bitter lupins are avoided by rabbits and aphids, sweet alkaloid
poor varieties are readily accepted (Wink 1998, 1992).
 Mass screening is still a labour and capital intensive strategy.
 Tolerance levels for individual ANFs and applications need to be
known so that plant breeders can define target levels in their
breeding programs.

27.  If the gene is known which encodes a toxic protein, genetic
engineering offers a set of methodologies at present to downregulate
or to knock out the respective activity.
 Strategies include the expression of antisense mRNA, of gene
targetting, and of synthetic oligonucleotides or ribozymes.
 Obstacles are often encountered in that relevant genes have not been
detected so far which is usually the situation for biosynthetic
enzymes of ANFs.
 Transformed plants need to be regenerated which is a severe
problem in most legumes.
Genetic engineering options

28. Reference: