Amino acid supplementation of proteins. I. The effect of supplementing ragi (Eleusine coracana) and ragi diets with lysine, threonine and skim milk powder on the nutritive value of proteins.

Cereals and millets form the staple fooc
of a large majority of the population ir
the world.1 They also form the main
source of proteins in the dietaries consumed
by the people in several developing
countries.1 The proteins of cereals and
millets are of medium nutritive value and
are lacking partially in certain essential
amino acids such as lysine and threonine.
2'3 Recent investigations have shown
that the nutritive value of the proteins of
certain cereals, e.g., wheat and rice, can be
improved to a significant extent by fortification
with lysine and threonine.4'5 The
important millets consumed widely in
different countries included kaffir corn
(Sorghum vulgare), pearl millet (Pennisetum
typhoideum) and ragi (Eleucine
coracana).6 Ragi is consumed by the
people in certain parts of India, Ceylon
and Africa.6 The protein content of ragi
has been reported to vary widely from 7.1
to 10.6 percent depending on the variety.2,3
Ragi proteins have been reported to be
a good source of all essential amino acids
except lysine and threonine.3 Kurien
et al7,8 reported that about 28% of the
total nitrogen in ragi is present in the
husk and the loss of ragi protein in digestion
is high. The protein efficiency ratio
of ragi proteins has been reported to be
0.71 and 2.0 at 5% and 10% levels of
protein intake respectively. 9,10 The overall
nutritive value of poor ragi diets as judged
by the growth of albino rats has been
found to be low (6-9g/week) and can be
improved markedly by the incorporation of
protein supplements, e.g , Indian multipurpose
food so as to provide abo'ut 4
percent extra protein in the diet indicating
thereby that the quality and level of protein
present in ragi diets (about 8 to 9%)
are inadequate to promote optimal
growth.11,12 The present investigation
relates to studies on the effects of supplementing
ragi and a poor ragi diet with
lysine and threonine or with skim milk
powder on the nutritive value of their
proteins.