RA 00110.pdf - OAR@ICRISAT

Table 6. Nitrogen distribution in sorghum and pearl
millet grain 1 .
Fraction
I Albumin and globulin
II Prolamin
I I I Cross-linked prolamin
IV Glutelin-like
V Glutclin
VI Residue
Total
% total nitrogen
Sorghum 2
Mean
17.4
6.4
18.8
4.0
35.7
10.6
92.9
Pearl
millet 3
Mean
25.0
28.4
2.7
5.5
18.4
3.9
83.9
1. Adapted from Jambunathan et al. (1981).
2. Based on 3 genotypes, M 35-1, CSH-8 and CSV-3.
3. Based on 4 genotypes, PHB-14, BK-560, WC-C75 and Ex-
Bornu.
explain why pearl millet proteins generally have a
higher digestibility than sorghum proteins (Hoseney
et al. 1981).
Carbohydrates
The starch content of pearl millet is similar to that of
sorghum and corn. The cooking properties of the
isolated starches are similar. The starch granules are
simple, undergo loss of birefringence at temperatures
similar to maize and sorghum starches, and
have similar cooking and gelling properties. The
apparent amylose content of pearl millet starches
ranges from 17-29%. The wet milling recovery of
starch from pearl millet is lower than that of
sorghum and maize.
Lipids
The level of free lipids extracted from pearl millet
cultivars varies from 3.0-7.4% with free fatty acid
levels of 2-12 mg 100 g -1 . The fatty acids of pearl
millet oil are similar to those of maize and sorghum
(Table 7).
Oleic, linoleic, and palmitic acids are the major
fatty acids of pearl millet oils. The bound lipids of
pearl millet are similar to bound lipids of sorghum
(Hoseney et al. 1981).
Polyphenols and Pigmentation
Reichert and Youngs (1979) determined that the
color of slate-grey pearl millet flour products is p H -
dependent, and can be controlled by soaking the
grain or flour in tamarind extract or sour milk. In
acid p H , a methanol extract of slate-grey pearl millet
flour is colorless, while at alkaline p H , the solution is
yellow-green. This is important in cooking pearl
millet porridge dishes, because a colorless porridge
is more acceptable than a yellow-green one. Reichert
(1979) determined that the grey color was due to the
presence of C-glycosylflavonoids.
The majority of the flavonoid pigments are located
in the peripheral endosperm of the kernel and in the
pericarp (McDonough 1986). In brown sorghum,
tannins cause digestibility and palatability problems
in the food products, however no condensed tannins
have been reported in pearl millet (Hulse et al. 1980,
McDonough and Rooney 1985). Differences were
noted among varieties with different kernel colors
that were tested with the Folin-Ciocalteu (FC) assay,
which measures total phenol content. The bronze
millet contained more extractable FC phenols than
either yellow or blue-grey millets. The phenol levels
in these millets were similar to those levels found in
Table 7. Fatty acid composition of sorghum and pearl millet cultivars 1 .
No. of
cultivars
Palmitic
(%)
Stearic
Oleic
Linoleic
(%)
Linolenic
(%)
Sorghum
Mean
Range
22
12
10-14
1
2-1
34
28-42
50
42-56
3
1-5
Pearl millet
Mean
Range
65
20
18-25
4
2-8
26
20-31
45
40-52
4
2-5
1. From Rooney (1978).
58