DESC:FIELD OF INVENTION
The present invention relates to a process for preparing convenient, ready-to-eat food product from sorghum grains and / or millets. More particularly, the present invention relates to a process for preparing flakes from sorghum grains and also from millets using conventional flaking machine, namely the ‘edge runner’. Further, the present invention relates to a process that enables to prepare flakes for sorghum and millets, with improved sensory and textural properties. Moreover, the process eliminates contamination of sand particles and seed coat content with the flakes and the process could be followed at cottage scale also. Also, the present invention elaborates the functioning of an apparatus for preparing flakes from sorghum and millet grains.

BACKGROUND OF INVENTION
Flaking of cereals such as corn and rice to a larger extent whereas wheat, barley, oats and millets also to some extent is practiced worldwide for preparation of snacks and breakfast cereals. Conventionally, rice flakes are prepared by toasting paddy or rough rice, hydrated to its equilibrium moisture content, in hot sand and then subjecting to flattening either by hand or leg pounding apparatus or pounding machine, or flattening in a machine called ‘edge runner’ for whivh reference may be made to Ananthachar, T. K., Narasimha, H. V., Shankar, R., Gopal, M. S. and Desikachar, S. R. 1982. Development of a continuous process for making Rice flakes. Journal of Food Science and Technology. 19:233-235. Subjecting the hydrated paddy to toasting in hot sand as heart transfer media facilitates gelatinization of the starchy endosperm of rice and renders it malleable enabling flattening or flaking by repeated pressing by beating but at the same time a substantial amount of the fine sand particles used as heat transfer media adhere to the surface of the paddy. However, during the flaking process the husk gets pulverised and separates out along with that the adhering sand particles. Thus the adhering sand particles do not seriously affect the eating quality of the product. Thus roasting the hydrated paddy in the sand for preparation of the flakes by conventional method does not affect the sensory attributes or the consumer acceptability of rice flakes and does not increase the sand and silica content to a noticeable extent. Hence, it is practical to prepare from paddy since the presence of distinct husk as a seed coat matter offers advantage.

But sorghum, pearl millet, maize also known as corn and finger millet, which are naked grains as they do not contain distinct husk tissue covering over the grain similar to paddy. Hence, during the process of flaking using hot sand as a heat transfer media the fine sand particles adhere to the surface of the grain. This occurs invariably because the grains are hydrated and soft. The moist surface facilitates adherence of the sand particles. When such a material is flaked or flattened, a substantial portion of the sand further gets impregnated in the soft endosperm and sticks to the flakes. The adhered sand drastically affects their eating quality especially causing uneasiness in the mouth during chewing. The presence of sand particles also imparts slight dark colour to the product and increasing the silica content and thus affects consumer acceptability and food value of the flakes. Because of these factors, the flakes from sorghum and millets prepared following sand roasting method will be non-edible and the process of flaking followed for the preparation of flakes from paddy by conventional method cannot be applied for preparation of flakes from sorghum and millet grains.

Another drawback of the conventional sand roasting process is that, the roasting pan is heated by wood powder or rice husk or the mixture of such materials fired manually. The hydrated grains after dropping in the hot sand are also agitated manually in an open pan. This lowers the temperature of the sand instantaneously and to raise the temperature again considerable fuel is used. More over the degree of the roasting happen to be subjective matter and because of that, very often under or over toasting of the material occurs. Under roasting leads to poor yield of flakes due to fracturing of the grains, whereas, over roasting causes charring of some of the grains. Both of these affect the yield as well as the quality of the product.

Yet another drawback of the existing practice of roasting the hydrated grains in sand media is that, the material soon after dropping in hot sand needs to be agitated manually, continuously that too in the open pan which is heated at the bottom. This is full of drudgery and health hazardous act due to exposure to constant heat. Similarly, the saw dust or such other material used as fuel are put to maintain flame continuously manually and the person manning this gets exposed to direct heat and dust till the work is completed. Moreover, the flaking units are not well ventilated and the workers are constantly exposed to heat and dust. These are highly health hazardous tasks.

Some of the prior arts are:
US7246762 relates to a production method of whole-grain corn flakes. The whole-grain corn flakes are produced by soaking the cleaned corn grits in potable water, and are put into a steam explosion cylinder for curing through steam explosion; the corn grits are exposed to a high-temperature refrigeration house for ageing followed by that passing the corn grits in a tablet press for tableting, drying, cooling and packaging to obtain the whole-grain corn flakes.

US6586028 discloses a method for preparing corn flakes, taking grains, neatly washing and peeling seed coat and the embryo; the dehulled corn dropped in boiling water and for 60 - 120 min for cooking to gelatinse the starch and to prepare malleable grits; the grits corn are rinsed with water 3 to 5 times, and again exposed to steam pressure in a cooker for 50 - 70 min, then cooled to room temperature and compressed in tableting machine to prepare flakes and the flakes are blistered at 180 to 200°C in an hot air or contact heat oven for 5 to 20 min to cause blistering.

CN103815295 relates to a method of preparation of cereal flakes is that, the flours or finer grits from corn or other cereals are mixed with water to raise the moisture content of the material to about 30% and then extruded in a twin screw extrusion cooker, the extrudate is cut in to small balls and then flattened in roller flaker. Subsequently, the flattened product is dried and blistered by exposing to direct or by contact heat at 180-240°C for a short time to prepare ready-to-flakes. The blistered flakes are coated with sugar syrup containing different flavor as desired. The flakes prepared by this technology are also called as ‘cereals’. This is highly capital intensive process and needs skilled manpower and the product is generally priced beyond the reach of the common population.

Although, sorghum and millets are known as nutri-cereals and flakes and other food products from sorghum and millets offer several health benefits such as lower incidents of duodenal ulcer, hypoglycemia, hypo-cholesterolemic properties, flaked products from sorghum and millets are scanty.

Flakes are generally precooked and require minimum preparation to consume as snacks and thus are classified as convenience foods and are suitable for consumption by all age groups. The flakes could also be used as quick cooking cereals. The current form of sorghum consumption is roti or chapathi (tortilla) or sangati (porridge). Roti preparation is highly cumbersome due to absence of protein called gluten, it requires skill and is time consuming. So diversifying processing technology to flaking of Sorghum would mean imparting convenience as you don’t need any special skill to make a recipe from flakes.

Yet flakes from sorghum and millets are not popular food products and are not manufactured commercially.

Accordingly, there exists a need for a process of preparing flakes from sorghum or millet grains, with highly desirable sensory characteristics as well as textural properties preferably using simple machinery without causing human drudgery. Accordingly, a process was developed for preparation of flakes from sorghum and millets which uses dry heat roasting instead of sand roasting followed conventionally for the preparation of rice flakes.

OBJECTS OF INVENTION
One or more of the problems for the preparation of flakes from cereals enumerated in prior art may be overcome by various embodiments of the present invention.
It is the main object of the present invention to provide a user-friendly process for preparing flakes from sorghum and millet using conventional flaking machines namely the ‘edge runner’.

It is another object of the present invention to provide a process for preparing flakes from sorghum and millet grains by avoiding sand as heat transfer medium and thereby eliminating the sand particles and also the seed coat matter as contaminants in the flakes and thus enhancing the consumer acceptability and food value of the sorghum and millet flakes.

It is another object of the present invention to provide a process of preparing microbiologically safe flakes from sorghum grains or millets using High Temperature Short Time (HTST) treatment either by hot air or by contact with hot surface of the grain roaster.

It is another object of the present invention is to utilize dry heat roasting apparatus in addition to conventional edge runner flaker for preparing flakes from sorghum grains or millets.

It is another object of the invention, wherein the sorghum grains have many different morphological features, colour, nutritional quality and many kinds of cultivars harvested in any region or different kinds of agro climatic conditions.

SUMMARY OF INVENTION
Thus according to the basic aspect of the present invention there is provided a process for preparation of flakes from sorghum and millet grains comprising steps of:
a. Soaking of clean sorghum and millet grains in cold or hot water for 6-24 hr at ambient conditions;
b. Draining off the water and tempering for a short time to remove adhering water to the sorghum and millet grains;
c. Subjecting hydrated sorghum and millet grains to high temperature short time treatment in grain roster till starch content of the sorghum and millet grains get gelatinised or cooked due to hydrothermal effect and the sorghum and millet grain are rendered malleable;
d. Flattening the cooked sorghum and millet grains in edge runner machine by repeated pressing between side wall of rotating machine and idle roll till the sorghum and millet grains flatten to the desired degree of thinness; and
e. Grading and drying the flakes.

It is another aspect of the present invention, wherein the sorghum and millet grains may be cleaned manually or mechanically using de-stoner-cum-aspirator-cum-grader machine to free the sorghum and millet grains from foreign matter, chaffs, stones and obnoxious seeds.

It is another aspect of the present invention, wherein the cleaned sorghum and millet grains are washed and soaked and heated up to about 80°C for 5-10 hr or in water at ambient temperature for 12 – 25 hr to hydrate to moisture level of 25-45%.

It is another aspect of the present invention, wherein the soaked sorghum and millet grains are washed to free from the leachates till the mild fermented odour is removed and heaped to facilitate absorption of the adhering moisture to the sorghum and millet grains.

It is another aspect of the present invention, wherein the hydrated sorghum and millet grains are dropped in to the grain roster heated to 180-340°C and the sorghum and millet grains are agitated continuously by rotating lever for 2-5 min and removed from the grain roster immediately by opening the exits value at the bottom of the grain roaster.

It is another aspect of the present invention, wherein the sorghum and millet grains get cooked or the starch content of the grain get gelatinized due to heat treatment in the grain roaster without rupturing the overall integrity of the sorghum and millet grains but causing slight swelling and rendering the grains malleable.

It is another aspect of the present invention, wherein the cooked sorghum and millet grains are transferred to the edge runner machine while they are still hot and the sorghum and millet grains are thrown to the sides of the machine due to centripetal force and get pressed repeatedly between metallic side wall of the rotating machine and the idle roller also rotating due to frictional force.

It is another aspect of the present invention, wherein the process of pressing continues till the sorghum and millet grains are flattened to the desirable thinness and then removed from the machine.
It is another aspect of the present invention, wherein during the process of flattening the sorghum and millet grains, the seed coat matter of the grains being relatively drier and brittle gets pulverized and fall though the perforated sheet of the machine.

It is another aspect of the present invention, wherein the flakes from sorghum and millets prepared will be near circular with slight fissured edges almost free from the seed coat and any kinds of contamination.

It is another aspect of the present invention, wherein the flakes may contain 6-10% protein, 1-3 % fat, 65-80% total carbohydrates, 60-70% pre-gelatinised starch, 1-3% minerals, 6-12% dietary fibre and 0.5-2% phytochemcials with nutraceutical charactristics.

BRIEF DESCRIPTION OF THE DRAWINGS:
Figure 1: is a flow chart for preparation of sorghum flakes according to the present invention.
Figure 2: illustrates perspective view of grain roaster for flaking sorghum and millet grains according to the present invention.
Figure 3: illustrates perspective view of an edge runner machine used for flaking sorghum and millet grains according to the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
The present invention as herein described relates to a process for preparing convenient, ready-to-eat food product from sorghum grains and / or millets. Further, the present invention relates to a process that enables to prepare flakes for sorghum and millets, with improved sensory and textural properties.

Referring to Figure 1, the process for preparing flakes from sorghum and millets comprising the steps of:
1. Cleaning sorghum grains or millets to free from impurities foreign and obnoxious matter, damaged and infested grains;
2. Washing and soaking the cleaned sorghum grains or millets in excess cold or warm water to rehydrate to their Equilibrium Moisture Content (EMC);
3. Draining of the adhered water and subjecting the hydrated sorghum grains or millets to High Temperature Short Time (HTST) treatment till the grain just cooked to gelatinize the starch without drying or popping in a vertical cone shaped grain roaster heated outside using electricity, LPG or fire wood;
4. Tempering the heat treated sorghum grains or millets for a short time to sweat out the surface moisture;
5. Flattening the precooked sorghum grains or millets by mechanical impact in an edge runner machine to desired thinness by retaining in the machine for suitable time;
6. Taking out the flakes from the machine and grading the flakes in sifter and drying the flakes to safe storage moisture; and
7. Packaging the dried flakes.

Seed coat matter of the sorghum and millet grains being dry and brittle gets pulverized and separates out through the perforated base surface of the machine automatically during flattening whereas the malleable endosperm gets flattened or flaked and facilitates collection easily.

In one embodiment of the present invention, the cleaned sorghum grains or millets soaked in water approximately at 10-70°C temperature for 6-24 hours attains approximately 25-45% moisture level.

It is another embodiment of the present invention, the soaked sorghum grains or millets are drained from water to free from adhering surface water and the grains after draining the water can be processed immediately or heaped and covered with moist gunny bags or insulating material to prevent dehydration and left for some time till used for roasting. The hydrated sorghum and millet grains are subjected to high temperature and short time treatment in a grain roaster maintained at temperature of 180-320°C with constant agitation to facilitate gelatinization of the starchy endosperm of the grains instead roasting in sand, thereby preventing contamination of flakes by sand particles and hence improving eating quality of the flakes. The hydrated sorghum and millets grains are agitated in the in the grain roaster for 2-5 min to plasticize the starch endosperm, said plasticized sorghum and millet grains removed from the grain roster, allowed to equilibrated for 2-5 min and then are flattened or flaked using ‘edge runner’ machine. For 2-10 min, to prepare flakes of desired thinness. Seed coat matter of the sorghum and millet grains gets pulverized into fine flour and separates out without causing any contamination to the edible matter of the sorghum and millet flakes. The flaked material is passed over perforated screen of 1- 3 mm perforations to separate out pulverized flakes. The sorghum and millet flakes are dried at 30 - 60oC temperature to produce flakes with a specified crispness and bulk density and storage stability.

Referring to Figures 2 and 3, the apparatus for preparing flakes from sorghum and millet grains comprising of de-stoner-cum-aspirator-cum-grader machine; cold or hot water soaking tanks; grain roaster heated by electricity, LPG or fire wood; flaking machine or edge runner; and tray drier. The flaking machine or edge runner further comprises of an idle roll; and perforated rotating screen.

The grain roaster comprises of cone shaped vertical drum rotating clockwise and provided with hopper to feed the material at the top and an outlet at the bottom having closing and opening lever and the entire drum encased by a circular drum having facility to heat the conical drum, and the conical drum provided with lever to mix the added material. The grain roaster is vertical metal cone shaped, said metal is preferably iron. The grain roaster is provided with rotary agitator and housed in enclosed circular equipment having provision to heat the cone from all sides. The grain roaster is heated by electricity or LPG or oil or fire wood. The idle roller exerts impact on the hydrothermally treated material, said grain roaster is normally batch type.

Referring to Figure 2, sorghum grains or millets are cleaned to separate out foreign matters, refraction and damaged kernels manually or using the de-stoner machine. The cleaned sorghum grains or millets are soaked for about 6-10 hours in hot water or about 12-24 hours in cold water to rehydrate the sorghum grains or millets till the same attain their equilibrium moisture continents (EMC) of 25-45% where the time duration for soaking depends upon the temperature of water. In the soaking process, the starch, protein and the cell wall contents absorb water and facilitate hydro-thermal treatment during roasting or HTST treatment. Subsequently the sorghum grains or millets are drained from the water and the surface adhering water is allowed to drive off.

The soaked or hydrated sorghum grains or millets are subjected to HTST treatment at temperature of approximately 180-320oC in the grain roaster to gelatinize the starch. The grain roaster is normally a batch type machine. The hydro-thermal treatment to the sorghum and millet grains during roasting causes little swelling of the sorghum grains or millets and partially ruptures the cell walls and causes gelatinization of starch, because of the effect of steam formed within the sorghum grains or millets. Pericarp or the seed coat matter prevents the steam to ooze out or the steam to come out and thus the endoplasm gets cooked completely and become malleable. When the soaked grains dropped in the grain roaster come into contact with hot surface as well as hot air and cause the heat transfers to the inner core of the grains leading to gelatinization of the starch in other terms the grains get cooked within the protective pericarp tissue.

Referring to Figure 3, the hydro-thermally treated grains after tempering are transferred to the edge runner machine in which the grains undergo repeated impact by passing between ideal roller and metallic wall surface of the edge runner, as result the grains get flattened to form flakes of desired thickness depending up the time of flattening. At the same process the seed coat matter gets pulverized and separates out through perforated rotating bottom screen of the edge runner. Even though the hydrothermally treated grains are subjected to repeated flattening in the edge runner machine the grains do not disintegrate because of the malleable nature of the endosperm, but at the same time the seed coat matter which is at higher degree of dryness compared to the inner portion of the grains get pulverised and separates out through the perforated rotating bottom screen of the edge runner machine. Thus the flakes produced from the sorghum and the millet grains are totally free from any kind of sand or such other foreign matter including the seed coat matter and the thickness of the flakes can be tailored to the desirable level by allowing the material inside the edge runner for a specific duration. The sorghum or millet flakes are dried at 30 - 60oC temperature by spreading in thin layer on a clean platform or mechanically using the tray drier to produce sorghum or millet flakes with a specified crispness and bulk density and with good storage stability. The flakes prepared from the said process can be further processed as conventional snacks, muesli, granule bar, cereal bar, spice mix etc. The produced flakes vary in thickness of specific range, diameter of specific range, slightly oval in shape, bright to translucent with desirable characteristic aroma and improved textural properties such as crisp in nature.

The foregoing aspects of the present invention are illustrated in the following examples:

Sorghum flakes are rich in nutrients viz protein (7.23%), dietary fiber (5.97%), Calcium (10.94 mg%) and iron (8.77 mg%). The values varied with different cultivars and the varieties Phule Vasudha and Phule Yashoda are the best when compared with the other varieties.

Example 1: Sorghum purchased from the local market was cleaned and soaked in potable water at ambient temperature for 12, 14 and 16 hr. During soaking the soak water was changed once. Each of the soaked material was subjected to roasting in the grain roaster for 210, 260 and 310 C for 60 to 120 Sec and flaking the material in the edge runner for 210 -270 sec. Every time the yield of the flakes was recorded. The brief account of the observations recorded in Tables 1, 2, 3, 4 and 5. The optimized flaking technology parameters were presented in Table 6.
Table 1: Soaking time vs Yield Table 2: Roasting temperature
vs Yield (Soaking time constant)

Table 3: Roasting time vs Yield Table 4: Incubation time vs Yield
(Soaking time and Roasting temperature constant) (Soaking time, Roasting temperature
and Roasting time constant)

Table 5: Flaking time Vs Yield Table 6: Jowar (thin) flakes
optimized parameters
(Soaking time, Roasting temperature,
Roasting time and Incubation time constant)

Sorghum is a coarse grain and is difficult to pound. However, with the advent of technology, Edge runner (flaking machine) along with roaster has made it possible to produce flakes from sorghum. Sorghum flakes produced from the flaking machine resembles rice flakes and the output is 60-70%.

Flakes prepared from the edge-runner were short, broad, almost circular and white in colour comparable to rice flakes. Grains tend to get gradually compressed randomly (both along length and width) in the edge-runner and appeared to have more damaged (frayed/ cracked) edges. Materials from edges of flakes appeared to be lost in the edge-runner process, due to the gradual thinning of the grain, where drying and powdering of the grain occurred (Shankara et al, 1984). Many properties of flakes such as cooking quality depend on its physical properties (Indudhara Swamy et al., 1971).

Length (l) and breadth (b) of flakes was determined as described by Bhattacharya et al., (1972). Surface area of flakes was computed using the formula p lb/4, assuming elliptical shape. Thickness of flakes was measured using venire calipers and values averaged. Bulk density (g/ ml) of flake samples was measured by 100 ml volume apparatus by tapping. The proximate composition viz moisture, fat, protein, fiber and carbohydrates were estimated by using standard AOAC (2005) methods. The amino acid profile, vitamins and mineral content was estimated and established for the nutritional portfolio. The physical properties (Table 7), recovery (yield) (Table 8) and the chemical composition of the flakes (Table 9) are given below.

Table 7: Physical properties of Sorghum flakes
Sample Volume (ml/ 100 g) Bulk Density (g/ml) Diameter (mm) Thickness (mm) Surface area*
(sq.mm)
L B
CSV-22 300 0.333 9.0 8.0 5.0 56.52
Phule Revati 305 0.327 9.0 7.0 5.0 49.45
Phule Chitra 304 0.328 8.0 7.0 6.0 43.96
Phule Maulee 301 0.332 8.3 7.0 5.0 45.65
CSV-18 299 0.334 8.5 7.3 5.2 48.75
CSH-15R 302 0.331 8.2 8.1 5.3 52.19
Phule Vasudha 306 0.326 9.5 8.4 4.9 62.70
Phule Yashoda 305 0.327 9.4 8.3 5.1 61.30
Phule Anuradha 301 0.332 8.4 7.5 5.3 49.50
M35-1 300 0.333 9.1 8.2 5.8 58.63
*Surface area calculated as p lb/4 an elliptical surface

Table 8: Recovery of flakes from different genotypes of sorghum

Sample / Recovery (Yield) Flakes (%) Broken (%) Husk (%)
CSV-22 52.77 18.23 29
Phule Revati 52.55 19.2 28.25
Phule Chitra 63.42 9.75 26.83
Phule Maulee 64.33 12.46 23.21
CSV-18 49.67 19.45 30.88
CSH-15R 62.08 18.37 19.55
Phule Vasudha 53.8 18.26 27.94
Phule Yashoda 57.86 14.25 27.89
Phule Anuradha 65.12 8.54 26.34
M35-1 63.42 12.31 24.27
Range 49.67-65.12 8.54-19.45 19.55-30.88
Mean ± SD 58.502 ± 5.55 15.082 ± 3.92 26.416 ± 3.11

Table 9: Chemical properties of Sorghum flakes (per 100 g)
Parameter M35-1 CSV-22 Phule Revati Phule Chitra Phule Maulee CSV-18 CSH-15R Phule Vasudha Phule Yashoda Phule Anuradha
Protein (g) 7.23 9.11 8.81 8.43 8.15 8.91 8.52 9.22 8.74 8.12
Fat (g) 1.79 1.88 1.23 1.56 1.76 1.66 1.82 1.43 1.53 1.64
Total Dietary Fibre (g) 5.97 5.42 5.97 5.5 5.74 5.6 6.01 5.51 6.04 5.43
Insoluble (g) 5.43 5.21 5.63 4.97 5.22 5.26 5.48 4.99 5.61 5.20
Soluble (g) 0.54 0.21 0.34 0.53 0.52 0.34 0.53 0.52 0.43 0.23
Carbohydrates (g) 73.8 1.75 1.07 1.64 1.73 1.64 1.58 1.53 1.87 1.64
Calcium (mg) 15.94 20.05 15.47 21.55 18.43 16.99 16.32 17.92 18.37 11.53
Magnesium (mg) 198 213 211 211 221 224 217 213 214 225
Copper (mg) 0.89 0.87 0.80 0.92 0.86 0.84 0.96 0.86 0.84 0.85
Manganese (mg) 180 171 183 191 172 169 187 192 184 175
Iron (mg) 8.77 4.08 4.36 3.96 4.67 4.76 4.45 4.17 3.87 4.23
Zinc (mg) 0.88 3.73 3.62 3.75 3.62 3.64 3.63 3.65 3.75 3.84
Phosphorus (mg) 510 503 491 503 483 503 501 511 512 497
Thiamine (mg) 0.45 0.43 0.33 0.42 0.41 0.47 0.51 0.42 0.34 0.39
Niacin (mg) 1.93 1.87 1.97 1.65 1.78 1.79 1,98 1.96 1.95 1.95
Riboflavin (mg) 0.15 0.13 0.12 0.14 0.10 0.13 0.12 0.12 0.14 0.13
Tot Folic Acid (µg) 1569 1573 1562 1453 1496 1488 1542 1467 1453 1432

Example 2: Ten Sorghum varieties viz. CSV-22, Phule Revati, Phule Chitra, Phule Maulee, CSV-18, CSH-15R, Phule Vasudha, Phule Yashoda, Phule Anuradha and M35-1 (25 kg) were cleaned using destoner machine to free from the stones, chaffs, broken grains and stone. The cleaned material was washed in potable water till the surface contaminants, immature grains and also the glumes etc including the floating’s in water were discarded. Then the material was soaked in water (one and half times the volume of the material). The soaking period was extended to 16 hr at ambient temperature. The soaked water was replenished once during the soaking period. After about 12 hr of soaking, the grains were again washed and the soaked water was drained off completely. The material was heaped and left for some time so that the adhering water was removed by draining. The hydrated material in 2 kg lots was dropped in to the grain roaster heated to 310°C and rotating at about 150 rpm. Shearing and agitation was continued till the grains just started busting identified by hissing sound. The grains were immediately taken out with the help of discharge lever, left for tempering for about 5 min and then transferred to the edge runner flaking machine which was put on to run at 350 rpm. After running for about 3 min the flattened material was taken out and passed on the screen to separate out the brokens. The brokens and the flakes were equilibrated and weighed to calculate the material balance, an average of 10 batches were taken for calculation.
Example 3: The by-product from flaking of sorghum is bran (seed-coat) powder and broken flakes. As sorghum bran and broken flakes are rich in fibre, iron and vitamin content it can be used to make various value added products.
The following are the economic significance of the said flaking process:
1. Sorghum and millets are primarily consumed in form as unleavened pancakes and also in the form of thick porridge but seldom processed, especially for production of convenient high value food products. Hence, with advent of this process where in sorghum and millets are converted to flakes may offer cheaper alternative to rice flakes of good quality which are nutritious.
2. Sorghum and millet flakes are circular or oval in shape and offer better nutrition benefits than traditional rice flakes owing to higher proportion of minerals, vitamins and antioxidants and also dietary fibre. The slow releasing carbohydrates in sorghum and millets will help in minimising the incidence of lifestyle diseases such as diabetes, obesity, etc.
3. The technology offers snacking and breakfast cereals preparation option thereby the demand for sorghum and millets will be enhanced due to convenience attached to the technology in question, in long run it would help to strengthen the demand for sorghum crop cultivation and aids the poor dry land farmers in the country.
4. The process is simple and does not require sophisticated equipments and machinery. The flakes following this process could be prepared manufactured at cottage scale industry making use of conventional grain cleaning units, soaking tanks, grain roaster and the edge runner machine.
5. The process can be applied to any kind of clean sorghum and millet grains irrespective of agro-climatic condition of harvest, variety, shape and size of the grains. Even grain with poor economic strata could also be processed to prepare flakes.
6. The flakes could be used in conventional manner similar to rice flakes or could be processed further to prepare value added sweet and savoury products.

The advantages of the present invention are as follows:
• Simple and mainly requires low price dry roasting and flaking machines which are available indigenously.
• The processing area doesn’t require any special parameters such as temperature and humidity control conditions and carried out at ambient conditions i.e. following good manufacture conditions.
• Permits to use clean and healthy grain irrespective of their region, agro-climatic conditions of cultivation, size, shape and color, hardness and also chemical composition.
• Permits to prepare flakes of different thickness and for different end uses.
• The flakes are generally pre-cooked and ready to use but are more suitable for seasoning and garnishing in the conventional way to prepare snacks.
• The sorghum or millet flakes is microbiologically safe as the grains undergo HTST treatment.
• The process makes use of a machine for toasting the hydrated grains and thus avoids manual toasting and thus prevents health hazardous act followed hitherto.

,CLAIMS:WE CLAIM:
1. A process for preparation of flakes from sorghum and millet grains comprising steps of:
a. Soaking of clean sorghum and millet grains in cold or hot water for 6-24 hr at ambient conditions;
b. Draining off the water and tempering for a short time to remove adhering water to the sorghum and millet grains;
c. Subjecting hydrated sorghum and millet grains to high temperature short time treatment in grain roster till starch content of the sorghum and millet grains get gelatinised or cooked due to hydrothermal effect and the sorghum and millet grain are rendered malleable;
d. Flattening the cooked sorghum and millet grains in edge runner machine by repeated pressing between side wall of rotating machine and idle roll till the sorghum and millet grains flatten to the desired degree of thinness; and
e. Grading and drying the flakes.

2. The process as claimed in claim 1, wherein the sorghum and millet grains may be cleaned manually or mechanically using de-stoner-cum-aspirator-cum-grader machine to free the sorghum and millet grains from foreign matter, chaffs, stones and obnoxious seeds.

3. The process as claimed in claims 1 and 2, wherein the cleaned sorghum and millet grains are washed and soaked and heated up to about 80°C for 5 – 10 hr or in water at ambient temperature for 12 – 25 hr to hydrate to moisture level of 25 -45%.

4. The process as claimed in claims 1-3, wherein the soaked sorghum and millet grains are washed to free from the leachates till the mild fermented odour is removed and heaped to facilitate absorption of the adhering moisture to the sorghum and millet grains.

5. The process as claimed in claims 1-4, wherein the hydrated sorghum and millet grains are dropped in to the grain roster heated to 180-340°C and the sorghum and millet grains are agitated continuously by rotating lever for 2-5 min and removed from the grain roster immediately by opening the exits value at the bottom of the grain roaster.

6. The process as claimed in claims 1-5, wherein the sorghum and millet grains get cooked or the starch content of the grain get gelatinized due to heat treatment in the grain roaster without rupturing the overall integrity of the sorghum and millet grains but causing slight swelling and rendering the grains malleable.

7. The process as claimed in claims 1-6, wherein the cooked sorghum and millet grains are transferred to the edge runner machine while they are still hot and the sorghum and millet grains are thrown to the sides of the machine due to centripetal force and get pressed repeatedly between metallic side wall of the rotating machine and the idle roller also rotating due to frictional force.

8. The process as claimed in claims 1-7, wherein the process of pressing continues till the sorghum and millet grains are flattened to the desirable thinness and then removed from the machine.

9. The process as claimed in claims 1-8, wherein during the process of flattening the sorghum and millet grains, the seed coat matter of the grains being relatively drier and brittle gets pulverized and fall though the perforated sheet of the machine.

10. The process as claimed in claims 1-9, wherein the flakes from sorghum and millets prepared will be near circular with slight fissured edges almost free from the seed coat and any kinds of contamination.

11. The process as claimed in claims 1-10, wherein the flakes may contain 6-10% protein, 1-3 % fat, 65-80% total carbohydrates, 60-70% pre-gelatinised starch, 1-3% minerals, 6-12% dietary fibre and 0.5-2% phytochemcials with nutraceutical charactristics.

References:
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AOAC. 2005. Official Methods of Analysis for ash of flour. Association of official analytical chemists. 18th Ed. Arlington VA 2209, USA. AOAC 923.03, chap 32, pp 2-4.
Chavan, U.D., Patil, S.S., Dayakar, R.B. and Patil, J.V. 2015. Processing of sorghum for flakes and their products. European Journal of Molecular Biology and Biochemistry, 2(1): 49-58.
Hibberd C.A., Wagner, D.G., Schemm, R.L.,Mitchell, E.D. Jr., Hintz, R.L And Weibel, D.E. 1982. Nutritive Characteristics of Different Varieties of Sorghum and Corn Grains. Journal of Animal Science. 55 (3):665-672.
Hulse, J. H., Laing, E. M. and Pearson, O. E. (eds.). 1980. Sorghum and the Millets: Their composition and nutritive value. Academic Press, New York pp. 256-267.
Indhudhara swamy, Y.M., Ali S. Z., Bhattacharya, K. R. 1971. Hydration of raw and parboiled rice and paddy at room temperature. Journal of Food Science Technology. 8 (1): 20-24.
Shankara, R. Ananthachar, T. K., Narasimha, H. V., Krishnamurthy, H., Desikachar, H. S. R. 1984. Improvements to the traditional edge runner process for rice flake production. Journal of Food Science Technology. 21: 121-123.