1. Cereal Chemistry
The grain protein content varies considerably, depending on whether
the harvest is from well irrigated highly fertilized fields or from rain fed,
low yielding fields to which less fertilizer has been applied. The warm wheat
growing areas generally have a higher grain protein content than the cool NHZ.
The hill wheat with low protein and a high spread factor is suitable for the
biscuit industry. PZ wheat is good for crackers and cookies, as it has a high
protein content and strong gluten. High molecular weight (HMW) gluten in Indian
wheat varies with the variety. A frequency of 2+12 for Glu-D is usual in >
70 of the Indian varieties and the rest have a 5+10 band. Similarly, the most
common Glu-A is band 2* in > 60% of the genotypes and the rest have either
band 1 or N (nil). Glu-B is very diverse, and an almost equal number of
varieties have either 7+9 or 7+8 or 17+18. The presence of band 7 or only band
20 is found in a few odd wheat varieties. In the CIMMYT material, In the CIMMYT
material, Pena (1995) observed that a maximum number of lines contain 2* as
Glu-A, 7+9 for Glu-B and 5+10 for Glu-D. The distribution pattern of the CIMMYT
material of 1994 is at variance with the Indian material sampled during 2002
despite the fact that the Indian national wheat improvement programme uses the
CIMMYT lines extensively in its breeding programme. This mixture of the HMW
gluten combinations present in Indian varieties is used for making various
value-added end products.
2. Dough Properties of Indian
Wheat
The contribution of gliadin and glutenins to gluten strength and
extensibility can be inferred from protein content, sedimentation value, dough
strength and dough extensibility, the crumb and the loaf volume of the bread.
The dough properties or rheological information are of importance in value
addition and product development. If the Alveograph ratio of dough tenacity or
P (maximum height of the curve) to extensibility or L (length of the curve) is
around 0.8 and the total work force (W) needed to cause rupture of the dough is above 200 (erg/g, or 10-4 J) then the bread volume
tends to be high and the quality of the product is good. If the flour is stored
at a high temperature (40 °C) the dough becomes inextensible (Censkowski et
al., 2000), and in many parts of India such high ambient temperatures prevail
for several days during summer and contribute to the quality variations in bread
during different seasons of the year. The milling and baking industries,
located primarily in the southern states, are short of wheat grain suitable for
bread and biscuit manufacture. Wheat sample data from different zones show
(Tab. 44) that the PZ produces the best wheat available for bread, as the loaf
volume and bread rating are high, but the quality is still below what is
achieved elsewhere in the world. The NHZ produce meets biscuit quality needs,
as the spread factor is the best. In both NHZ and PZ wheat production is lower
and there is hardly any marketable surplus. Also these places are far away from the
location of the biscuit industry, which makes surface transport of the grain
expensive and difficult. The CZ grain meets the demand of the whole grain flour
market for the flat, non-fermented Indian bread or chapatti and that of NWPZ
and NEPZ is rated next only to the CZ. Growing urbanization and the increasing
employment of women has changed kitchen needs, and the branded whole grain
flour or atta has created a new market.
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Tab. 44: Quality attributes of bread wheat samples of 2002, from
different zonesa
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India has approximately 1.5 mio ha under durum wheat. It is mostly
confined to PZ and CZ, but there are very small areas in Punjab and NWPZ too.
The Indian durum has very hard grain and good (approximately 7 ppm) beta
carotene. The protein content is approximately 15% in Khapli wheat, the grain
is long and deep-golden, with shrivelled cheeks. These tetraploids are used to
manufacture semolina, bulgur and several extruded products of high quality.
3. Grain Classification
Wheat grain classification is essential for trade and quality control
as the buyer is able to understand the utilities of the supply and negotiate a
price. The approach rests on two parameters, namely the physical purity or
"Grade" and the other grouping called "Class" which is
based on the grain quality traits. Tab. 45 shows the different grades
recommended for adoption in India (Gupta, 2002).
The following section describes the five major Indian wheat classes.
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Tab. 45: Suggested grading standards for Indian wheat.
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Indian Medium Hard Bread Wheat
This is the standard mill quality wheat. Medium grain size and
appearance, medium hard, dry gluten 9%, protein > 10%, > HLW 76, seed
moisture 11%, total defects 6%, extraction efficiency < 69% sedimentation
value < 40. The flour is suitable for non-fermented flat Indian bread
chapatti and a number of other ethnic food preparations such as naan, tandori, rumali,
roti, puri, bhatore etc. All these ethnic foods are made out of the whole grain
flour of this class. This is the largest wheat surplus India produces. It is
consumed domestically in various forms. The wheat varieties PBW 343, HD 2786,
Raj 3077, Lok 1, GW 273 etc., fall into this class.
Indian Hard Bread Wheat
(Premium Wheat)
Bold and lustrous grain, dry gluten 9%, protein > 12%, HLW approx.
80, seed moisture 11%; extraction efficiency is approx. 70%. It is suitable for
a variety of fermented and non-fermented breads. The bread quality and rating
is high, and a variety of flours can be made from the grain. The varieties C
306, Sujatha, HW 2004, HD 2189, DWR 162, GW 496, Lok 1 (some samples from PZ)
and HD 2733 fall into this class. The "cream" of wheat, maida12 and
extruded products made from this class have a market chiefly in South Indian
states.
Indian Soft Bread Wheat
(Biscuit Wheat)
Yellowish / white grain, grain hardness < 5.3, soft textured, dry
gluten 7%, protein < 9.5%, HLW 75, seed moisture 12%, extraction efficiency
approx. 68%, biscuit spread factor > 7.5. It is suitable for eastern food
habits, biscuit- making etc. Local land races of the NHZ and Pissi, a local
land race of CZ, fall into this cluster and meet the requirements of the
biscuit industry.
Indian Durum Wheat
Large and hard kernel, vitreous grain, betacarotene > 5 ppm,
protein > 12%, HLW > 78. Seed moisture is approx. 11%. The durum
varieties PDW 233, WH 896, HI 8498, Raj 1555, MACS 2846 etc., fall into this
class. It is extensively used for extruded products, semolina and pasta, and
for pizza bases, bulgur etc.
Indian Dicoccum Wheat
Hard kernel, longish grain, not plump, betacarotene > 5 ppm, HLW
> 78, protein > 13% and seed moisture 10%. It is suitable for breakfast
cereal, semolina, for porridge, extruded products and for high-protein foods.
Local Khapli land races, NP 200, DDK 1009 etc., fall into this class.
Current Indian Wheat Grading
System
Indian wheat is currently divided into different grades based on
physical purity, admixtures, broken kernels, shrivelled kernels etc. The
suggested grades (Nagarajan, 2004) have not been put into practice as there is
no declared difference in price, although in the grain market there is a
variation in price on the basis of arbitrary assessment made by the grain
merchant. The Indian grain grading system is therefore comparable with the
practices followed in other parts of the world and aimed at promoting proper
auctioning and pricing of the produce. These developments should be viewed in
the context of our need to have harmonized and well accepted grain quality
standards and of India's preparedness to become a partner in the global grain
trade.
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