Title of Invention

A PROCESS FOR THE PREPARATION OF SEMOLINA FROM PEARL MILLET WITH ENHANCED SHELF LIFE

Abstract The invention deals with A process for the production of semolina from pearl millet with enhanced shelf life. The production of semolina from pearl millet is hitherto not known. The process utilizes the use of tartaric acid at very low concentration during soaking, and later steaming the soaked grains at atmospheric pressure thus avoiding complicated milling systems. The processed grains are now suitable to be converted to semolina which is hitherto not available. The semolina thus obtained had an improved colour, cooking quality and shelf life almost similar to semolina obtained from wheat / rice and can replace rice or wheat in ready mix formulations for Indian traditional foods.
Full Text This invention relates to a process for the production of semolina from pearl millet with enhanced shelf life.
Pearl millet (Pennisetum americanum(L)Leeke is one of the most important cereals ranking sixth in the worlds cereal production and is widely cultivated in India and Africa. Although in India it is the fourth important crop after wheat, rice and sorghum, unfortunately has remained a food only for economically weaker sections primarily due to coarseness, grey to yellow green colour, which imparts a bitter taste and poor shelf life (Panwal J. H. and Pawar J. Food Science and Technol., vol. 26 1989 79-82). These are some of the reasons for its poor acceptability by rice/ wheat eaters. The removal of bran containing the pigments that impart grey colour to the flour and to obtain flour with improved colour and shelf life is the major objective while processing pearl millet grains. The present consumption of this grain is in the form of flour made into mostly rotis, where in the grains are converted to flour as and when required and there is no other processing technology by which the utilization of this grain could be diversified. In order to obtain a fairly white flour, bran up to 15-18 % has to be removed which will reduce the flour yield. Literature review reveals that there is very little information on the production of semolina from pearl millet grains. Pearl millet endosperm is comparatively softer and the coarse grit (~1mm) yield is itself very low 60-65% (Jain and Bal, 1997 J. Food Engg. 31:297-304) which may still reduce when grain is further ground to obtain semolina similar to that of wheat semolina. In order to improve the yield of semolina, grains need to be hardened.by the use of hydrothermal treatment. The process of parboiling however, imparts a dull and dark colour to the grain and this change in colour is very prominent in pearl millet grains, making the grain highly unacceptable. The main objective of the present investigation is to improve the yield of semolina, improve the colour and acceptability and also to increase the shelf life of the semolina.

Relevant literatures that have claimed to improve the colour and shelf life of the flour /semolina obtained from pearl millet have been cited along with some of the drawbacks.
Reference may be to a study by Chavan et al. Chavan J.K and Kachare, DP. 1994, J. Food Sci. Technol Vol. 31 80-81) where in the grains were soaked in 0.05N Hydrochloric acid for 12h at ambient temperature, the grains were then washed and dried at 40° C for another 12h, the resultant flour from the dried grains were tested for rancidity development which had been arrested. The main drawback of this study is the long soaking duration which had imparted sourness to the flour making it unacceptable. The other main drawback is the need of an oven which had to be maintained at a constant temperature for another 12 hours. The other drawback of this study is that the shelf life was studied only for a very short period of 30 days. No attempt in this study was made to produce grits or semolina from the processed grains.
Reference may be to yet another study by Panwal and Pawar (Panwal J. H. and Pawar J. Food Science and Technol., vol. 26 1989 79-82). In this study pearl millet grains were soaked for 3 to 24h in 0.2N HCI and it was observed that to obtain grains with an improved colour a 12h soaking duration was necessary. The main drawback of this study is the high concentration and long duration of soaking in acid solution. The other drawback is that no efforts were made to study the shelf life of the bleached flour. The other main drawback is that the effect of this treatment on semolina yield and its shelf life was not studied.
In another study by Young et al. (Young, R., Haidara, M., Rooney, L.W and Waniska, R.D. J. Cereal Science, 1990), sorghum grains were parboiled to use it like a rice like product (whole grain) after decorticating. This process although improved the endosperm texture and yield of

decorticated grains. The process had many drawbacks, it involves cumbersome steps soaking in boiling water, boiling for 10 sec, left to soak and later cooled for another 12h, again boiled and finally spread in a thin layer for 72h to dry. The other main drawback in this study is the intermittent short boiling steps which may be very critical and may be difficult to maintain. The
other drawback in this study is that grains after parboiling had a dark appearance which may affect its consumer acceptability. The other drawback is that the shelf life of the parboiled grains has not been studied.
Reference may be made to yet another study by Rathi et al, 2003 (Rathi A., Kawatra, A. and Sehgal, Food Chem.). The pearl millet grains in this study were depigmented by soaking in 0.2N HCI. For 18h, this was followed by washing, blanching (98 C, 30Sec.) and then dried in the sun. The main drawback in this study is that the high concentration of acid and the long soaking duration of 18h which may impart a sour taste to the product. The other draw back is that shelf life was not studied.
The main objective of the present invention is to provide a process for the production of semolina from pearl millet with enhanced shelf life convenience product from pearl millet.
Another objective is to prepare semolina for habitual and non-habitual consumers in the form of improved, shelf stable refined semolina suitable to prepare traditional products like Idli, Dosa, uppma etc.
Yet another objective of the objective of the investigation is to improve yield and colour of the semolina from pearl millet
Still another objective is to improve the cooking characteristics of the semolina, comparable to that of wheat /rice semolina/grit
Novelty
Novelty of the invention resides in providing semolina from pearl millet which is hitherto not known and inventive steps of this invention lie in the fact that the process developed utilizes the use of tartaric acid at very low concentration during soaking, and later steaming the soaked grains at atmospheric pressure thus avoiding complicated milling systems. The processed grains


are now suitable to be converted to semolina which is hitherto not available. The semolina thus obtained had an improved colour, cooking quality and shelf life almost similar to semolina obtained from wheat / rice and can replace rice or wheat in ready mix formulations for Indian traditional foods.
Accordingly the present invention relates to a process for the production of semolina from pearl millet with enhanced shelf-life which comprises;
a)grading of pearl millet grains to obtain uniform grains,
b)polishing the grains mechanically to remove 4-6% adhering bran, c soaking the polished grains in 70-75 degree C hot water containing 0.01 to 0.1 N tartaric acid for period of 1-12 hours, d) steaming the soaked grains for period of 10-25 minutes at a temperature ranging between 97-100 degree C, e) cooling the steamed grains by spreading under the shade for 12-48 hours and f) grinding the soaked and steamed grains in break rolls to obtain semolina ranging between 701-350 microns with improved shelf life of 3-4 months.
In an embodiment of the present invention, the yield of semolina is in the range of 50-75%. In an embodiment of the present invention, the semolina obtained has whiteness in the range of 20 to 26%, volume expansion 380 to 410 cc/100grams, water solubility index of 2.0 to 2.4 and swelling capacity of 2.9 to 3.6.
In an embodiment of the present invention, the the shelf-life of the semolina obtained is in the range of 3-4 months .
Any minor modification or changes or improvements, which could be apparent to the person familiar in the field of art of this invention, also are included in the scope of this invention. This invention is further illustrated with the following examples which should not, however be construed to limit the scope of invention.
Example 1
Pearl millet grains (1kg) were first decorticated to remove 5 % bran by polishing in a cone polisher, before polishing the grains were tempered with 3% water for 3 min. The decorticated grains were soaked in 3 liters of hot water (75 °C) for 1 h containing 0.1 N tartaric acid, after 1h the water was drained and grains were washed with tap water and allowed to drain for 1h. The soaked and drained grains were spread in a wire mesh tray in a 1" thick layer and steamed for 15 min. The steamed grains were spread in a thin layer and allowed to dry for 48 h in shade. The dried grains were passed through a coarse break roll and a fine break roll to obtain semolina which was sieved using various BSS sieves of different size openings viz. 18, 22, 32, 44. The semolina was sieved through each sieve and the plus fraction retained and percent yield, whiteness, transparency obtained for each fraction.

ICTP8203
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Local
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It was observed that the yield of semolina of mesh size 22 increased upon soaking in tartaric acid and the coarser fraction +18 decreased, an improvement in whiteness and transparency of the tartaric acid soaked semolina was also observed.
Example 2
Pearl millet grains (1kg) were first decorticated to remove 5% bran by polishing in a cone polisher, before polishing the grains were tempered with 3% water for 3 min. The decorticated grains were soaked in 3 liters of hot water (75 °C) for 5 h containing 0.06 N tartaric acid, after 5h the water was drained and grains were washed with tap water and allowed to drain for 1h. The soaked and drained grains were spread in a wire mesh tray in a 1" thick layer and steamed fat atmospheric pressure at a temperature of 97-100 ° C for 15 min. The steamed grains were spread in a thin layer and allowed to dry for 48 h in shade. The dried grains were passed through a coarse break roll and a fine break roll to obtain semolina which was passed through various BSS sieves with different mesh openings of 18, 22, 32, 44.

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The semolina was sieved through each sieve and the plus fraction retained and percent yield calculated for each fraction. It was observed that grains soaked without tartaric acid yielded higher fraction of the coarser fraction while, that soaked in tartaric acid yielded increased percentage of the finer fraction i.e., +22 fraction which was highly suitable for the preparation of Indian traditional products.
Example 3
Pearl millet grains of variety ICTP8203 (1kg) were first decorticated to remove 5 % bran by polishing in a cone polisher, before polishing the grains were tempered with 3% water for 3 min. The decorticated grains were soaked in 3 liters of hot water (75 ° C) for 5 h containing 0.06N tartaric acid, after 1h the water was drained and grains were washed with tap water and allowed to drain for 1h. The soaked and drained grains were spread in a wire mesh tray in a 1" thick layer and steamed for 15 min. The steamed grains were spread in a thin layer and allowed to dry for 48 h in shade. The dried grains were passed through a coarse break roll and fine break rolls to obtain semolina of different mesh sizes by passing through 18, 22, 32 and 44 BSS meshes. The semolina was sieved through each sieve and the plus fraction of each sieve retained and cooking characteristics like volume expansion, water solubility, swelling capacity of +22 and +35 fraction were determined and compared with wheat and rice semolina by standard procedures. For volume expansion 10g of semolina was taken in a graduated boiling tube and semolina cooked in 2.5 times water at atmospheric pressure for 45 min. and volume after cooking noted. Water solubility index of the semolina fractions was done by soaking 2.5g

of the semolina from raw and processed grains in 30 ml of water and left to stand for 30 min. The mixture was centrifuged at 3000rpm for 10 min. The mixture was centrifuged at 3000 rpm for 10 min. The supernatant was carefully transferred to a tared Petri plate and evaporated to dryness. The residue was weighed and solubility index calculated by taking the ratio of the initial and final weights. Swelling capacity of the semolina was obtained by taking the initial and final weights of the filtrate after centrifuging. It was observed that volume of the semolina obtained after treatment with tartaric acid had an increased volume after cooking when compared to semolina obtained from raw grains and semolina obtained from grains soaked in water without tartaric acid. It was also observed that water solubility index was lesser in the improved semolina when compared to semolina obtained from raw grains. The swelling capability of semolina obtained from tartaric acid treated grains was higher when compared to the semolina obtained from raw grains and grains soaked without tartaric acid. The functional properties of the improved semolina were also comparable to the semolina obtained from wheat and rice.
Volume expansion (cc/100g) of semolina
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Water Solubility index of semolina
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Swelling capacity of semolina
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Example 4
Pearl millet grains of variety ICTP8203 (1kg) were first decorticated to remove 5 % bran by polishing in a cone polisher, before polishing the grains were tempered with 3% water for 3 min. The decorticated grains

were soaked in 3 liters of hot water (75° C) for 5 h containing 0.06N tartaric acid, after 1h the water was drained and grains were washed with tap water and allowed to drain for 1h. The soaked and 15 min. steamed grains were spread in a thin layer and allowed to dry for 48 h in shade. The dried grains were passed through a coarse break roll and fine break rolls to obtain semolina of different mesh sizes by sieving through 18, 22, 32 and 44 BSS meshes. The semolina was sieved through each sieve and the plus fraction retained. Semolina was packed in polypropylene bags of 200 gauge and stored at ambient conditions of 65 % RH and 28° C and at regular intervals of one month the semolina was analysed for the changes in free fatty acid development in the major fraction i.e., +22 fraction was determined at regular intervals by standard procedures. It was observed that free fatty acid content did not increase beyond 10% in treated semolina where as in the untreated raw semolina it kept on increasing and by the first month itself it was beyond the 10% level.
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Advantages
a. The process enables the production of pearl millet semolina which
is stable for a period of 3-4 months against deteriorative changes as
exhibited by the arrest in the Free Fatty Acid content of the flour
b. The process increases the yield of semolina particularly +22 and
+32 fraction which is comparable to the semolina obtained from
wheat and rice and which is also suitable to prepare Indian
traditional products
c. The process enables the production of semolina with improved
colour, thereby improving the acceptability among traditional and
non traditional consumers
d. The process enables the production of semolina with improved
functional properties like water absorption, water solubility index
etc. which is comparable to wheat/ rice semolina.
e. The process enables the production of shelf-stable semolina from
pearl millet which may be an improved base for ready-mixes for
traditional products like Idli, cfosa,etc.
f. The process therefore enables diversification of pearl millet grains
among the non traditional consumers and also improve the
utilization of pearl millet which otherwise has a very limited scope.





We claim:
1. A process for the production of semolina from pearl millet with
enhanced shelf-life which comprises;
a) grading of pearl millet grains to obtain uniform grains,
b) polishing the grains mechanically to remove 4-6% adhering bran,
c) soaking the polished grains in 70-75 degree C hot water containing 0.01 to 0.1 N tartaric acid for period of 1-12 hours,
d) steaming the soaked grains for period of 10-25 minutes at a temperature ranging between 97-100 degree C,
e) cooling the steamed grains by spreading under the shade for 12-48 hours and
f) grinding the soaked and steamed grains in break rolls to obtain semolina ranging between 701-
350 microns with improved shelf life of 3-4 months.
2. A process as claimed in claim 1, wherein the yield of semolina is in the range of 50-75%. 3 A process for the production of semolina from pearl millet with enhanced shelf life substantially as here in described with references to the examples accompanying this specifications.

Documents:

731-DEL-2005-Abstract-(06-03-2012).pdf

731-DEL-2005-Abstract-(29-03-2011).pdf

731-del-2005-abstract.pdf

731-DEL-2005-Claims-(29-03-2011).pdf

731-del-2005-claims.pdf

731-DEL-2005-Correspondence Others-(06-03-2012).pdf

731-DEL-2005-Correspondence Others-(29-03-2011).pdf

731-del-2005-correspondence-others.pdf

731-del-2005-description (complete).pdf

731-DEL-2005-Description Complete-(29-03-2011).pdf

731-DEL-2005-Form-1-(06-03-2012).pdf

731-del-2005-form-1.pdf

731-del-2005-form-18.pdf

731-del-2005-form-2.pdf

731-DEL-2005-Form-3-(29-03-2011).pdf

731-DEL-2005-GPA-(06-03-2012).pdf


Patent Number 247868
Indian Patent Application Number 731/DEL/2005
PG Journal Number 22/2011
Publication Date 03-Jun-2011
Grant Date 27-May-2011
Date of Filing 31-Mar-2005
Name of Patentee COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
Applicant Address ANUSANDHAN BHAWAN, RAFI MARG, NEW DELHI-110 001, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 MEERA M.S GRAIN SCIENCE & TECHNOLOGY CFTRI, MYSORE
PCT International Classification Number A23L1/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA