1532.5 Amino acid composition
Amino acid analysis was carried out by hydrolysing
the samples in sealed ampoules in vacuo with 6 N
HCl and incubated at 110ºC for 22 hours (Darragh,
2005). Excess acid was removed in a flash evapora-
tor under reduced pressure at a temperature of less
than 40ºC. The sample was then dissolved in a cit-
rate buffer (pH 2.2) and loaded into an automatic
amino acid analyser (Biochrom-30, Cambridge, UK).
Methionine and cysteine was determined separately
after performic acid oxidation (Moore, 1963). Tryp-
tophan was quantified after barytic hydrolysis of the
samples according to the method described by
Landry and Delhaye (1992). Each amino acid was
identified and quantified using authentic standards
(National Institute of Standards and Technology,
SRM 2389). The amino acid score was calculated
using the FAO/WHO/UNU suggested pattern of
amino acid requirement for pre-school children ( 2 –
5 years) (FAO/WHO/UNU, 1985).
2 .6 Fatty acid composition
The fatty acid composition was determined after di-
rect methylation of the samples according to the
method of O’ Fallon et al. ( 2007 ). The fatty acid
methyl esters were analysed in a Shimadzu 2010 GC
equipped with Flame Ionization Detector (FID) and
SP2560 column (100 m x 0.25 mm x 0.2 mm). Injec-
tion was achieved by splitless mode and the injec-
tion port and detector were maintained at 250°C.
Nitrogen was used as carrier gas and the tempera-
ture programme was from 140°C to 230°C with a
ramp rate of 4°C/min. Individual peaks were identi-
fied by retention time using SupelcoTM37 compo-
nent FAME MIX. Fatty acid composition was
expressed as a percentage of total fatty acids.
2.7 Statistical calculations
Data analysis was carried out using SPSS (Version
1 8: Chicago, IL). Descriptive statistics, namely
mean, range and standard deviation, were calcu-
lated. Pearson correlation coefficients were carried
out among the different nutrients of interest. P val-
ues were two-tailed and two significant levels
(P<0.05 and 0.01) were used.3. Results and discussions
3.1 Proximate composition
The macronutrient composition of all the rice vari-
eties is listed in table 2.Table 2 .Proximate composition and dietary fiber
content of 269 high yielding Indian rice varietiesParameter N Mean ± SD RangeMoisture (g/100g) 269 9.69 ± 1.37 6.15 – 12.66
Protein (g/100g) 269 9.47 ± 1.22 6.92 – 12.98
Fat (g/100g) 269 2. 3 6 ± 0.46 1.2 3 – 3 .77
Ash (g/100g) 269 1. 3 9 ± 0.18 0.90 – 1.99
Insoluble dietary fibre (g/100g) 205 3.62 ± 3.64 3. 13.90
Soluble dietary fibre (g/100g) 105 0.79 ± 0.06 0.66 – 0.92
Total dietary fibre (g/100g) 105 4.41 ± 0.17 3.99 – 4.71
Carbohydrate (g/100g) 105 71.79 ± 1.37 68.04 – 75.77
Energy (kcal) 105 3 47 ± 3 .64 3 40 - 356All samples had moisture content varying between
6.15 and 11.91 g/100 g within the limit of 12 g/100 g
normally recommended for safe storage of
processed rice. Brown rice protein content in 269 cul-
tivars studied ranged from 6.92 to 12.98 g/100 g. The
width between the highest and the lowest protein
content was 6 g/100 g. The average rice protein con-
tent of 9.43 g/100 g found in the present study was
much higher than the reported value of 6.88 g/100 g
in the Indian Food Composition Tables (Gopalan et al.,
1989 ) indicating a general increase of protein content
in Indian rice varieties. Factors such as environmen-
tal condition, soil fertility, fertilizer use and post-har-
vest processing can influence the protein content of
rice; however, the present study examines only the
varietal difference and not the other factors that can
influence protein content in rice.
Protein content in rice due to varietal differences has
been reported to be in the range of 4.5 to 15.9 g/10 0
g (Juliano and Villareal, 1993). Compared to the pres-
ent study, Chandel et al. ( 2010 ) has reported lower