151Abstract
Rice research in India has focused mainly on in-
creasing yield and little is known of the nutrient
composition of many of the country’s rice varieties.
This study investigates the variations in the nutrient
content of 269 high-yielding Indian rice cultivars.
Protein content ranged from 6.92 to 12.98 g/100 g
with a mean of 9.43 ± 1.22 g/100 g. The majority of
the samples (51%) had protein content between 9
and 12 g/100 g. Mean crude fat content was 2.38 ±
0.46 g/100 g and as many as 30 cultivars had more
than 3 g/100 g. Moderate levels of total dietary fibre
(3.99–4.71 g/100 g) were observed in the brown rice
samples. Mean ash content was 1.39 ± 0.18 g/100 g
and 36 percent of the samples had ash content be-
tween 1.5 and 2.0 g/100 g indicating mineral abun-
dance in many rice varieties. High concentrations of
macro-elements such as phosphorus (330 ± 81
mg/100 g), potassium (253 ± 27.81 mg/100 g) mag-
nesium (129 ± 16 mg/100 g) and calcium (13.12 ±
2.66 mg/100 g) were observed. Grain iron content
ranged from 0.57 to 4.04 mg/100 g with an average
of 1.36 ± 0.59 mg/100 g. The coefficient of variation
observed for grain iron content was as high as 4 3
percent. Grain zinc content ranged from 1.46 to 3.8 7
mg/100 g with a coefficient of variation of 19 per-
cent. Essential amino acids made up 39 percent of
the total amino acids. The amino acid score ranged
from 59 to 73 (mean 65 ± 3.42) and Lysine was the
limiting amino acid. Palmitic (range 20–26%), oleic
(30–37%) and linoleic acids (33–42%) accounted for
more than 92 percent of the total fatty acids in rice.
The study has revealed diverse rice varieties with
wide-ranging nutrients that can be utilized in breed-
ing programmes to effectively increase protein and
micronutrient content in rice.
- Introduction
Rice is rich in genetic diversity with thousands of va-
rieties cultivated in more than 1 00 countries around
the world. Nearly all cultivated rice is Oryza sativa L.
with a small amount of O. glaberrima grown in
Africa. It is estimated that there are 1 20 000 differ-
ent cultivars ranging from traditional rice varieties
to the commercially bred elite cultivars (Londo et
al., 2006). In its natural state, rice comes in many
different colours prized for their nutrient and health
properties. Rice is tied to cultures and livelihoods
symbolizing life and prosperity for billions of peo-
ple playing a fundamental role in the world food se-
curity and socio-economic development. To
emphasize the importance of rice, the UN General
Assembly declared 2004 the International Year of
Rice under the slogan “Rice is Life” (FAO, 2004).
India is the largest rice-growing country accounting
for one-third of the world acreage under rice culti-
vation. Rice is grown in almost all the Indian states
covering more than 30 percent of the total cultivated
area in the country. India’s food production is pro-
jected to touch 2 3 5 million tonnes during 2010–11,
of which rice will account for 9 4. 5 million tonnes
(Directorate of Economics and Statistics, 2010 ).
Each year an estimated 408 661 million tonnes of
rice is consumed across the globe accounting for 20
percent of the world’s total calorie intake. The
biggest public health challenge both globally and in
rice-consuming countries comes from micronutri-
ent deficiencies of iron, zinc, vitamin A and iodine
affecting more than 3 billion people worldwide
(WHO, 2002). The proportion of the global popula-
tion suffering from micronutrient deficiencies has
increased over the last four decades largely due to
the increase in acreage under rice and wheat culti-
vation at the expense of pulse crops (a much richer
source of micronutrients) and to changing dietary
habits (Graham et al., 2007). India has the highest
incidence of undernutrition in the world, and of the
micronutrient deficiencies, iron deficiency anaemia
is the most serious public health problem in the
country (NNMB, 2006).
In the past, generic food composition data were con-
sidered sufficient for most purposes but today the
usefulness of cultivar-specific composition data is
becoming increasingly acknowledged for under-
standing diet-related morbidity and mortality. Sig-
nificant cultivar-specific differences have been