AU2020200060A1 - Post harvest treatment of paddy, to retain nutrients and obtain rice with low glycemic index - Google Patents

Abstract

The present invention relates to a method for using selected varieties of non-basmathi paddy to produce milled rice and products thereof with higher protein content, low glycemic index and improved culinary properties. The resultant rice product and by product are desired because they have low glycemic index (<55%) which reduces the risk of hyperglycemia and also suitable for reduction of obesity. Such processed rice with lower glycemic index (GI) will be needed for the traditional rice consumers, particularly the diabetic subjects who will otherwise be advised to consume non-rice cereal, grains.

Description

POST HARVEST TREATMENT OF PADDY, TO RETAIN NUTRIENTS AND OBTAIN RICE WITH LOW GLYCEMIC INDEX

NOVELTY OF THE PROCESS:1. Selection of Non basmati rice varieties with appropriate amylose content i.e. with amylose content in the range of 20-28 % to achieve reduced GI (GI Less than 55%).

2. Providing the protocol for steaming (at appropriate paddy moisture), Tempering (Resting the steamed paddy in stages for desired time standardized), to promote the development of resistant starch (slow digesting), aimed at reducing the GI of the processed rice, and defining conditions for drying in stages, the steamed and tempered paddy.

3. Applying the above protocol to the aged rice (about 6 month) for obtaining better reduction of GI

To sum up, providing total processing protocol (selection of appropriate paddy variety, hydrothermal treatment and milling protocol) for producing high quality polished rice (Sona pearl) with low GI, relatively high in protein content and improved culinary properties for consumption as cooked rice and also provide by products (broken rice and pure bran )for wider consumption.

IMPORTANCE AND NEED FOR PRESENT INVESTIGATION

More than half the population of the world depends on rice, which is grown on nearly 150 million hectares of land with a global production of more than 520 million tones.

Rice is unique among cereals in that it has glutelin as the major storage protein,(~80 %), which is more balanced in terms of amino acid content than other cereal storage proteins, which comprises prolamin which is deficient in lysine and tryptophan content. But during processing of rough rice (Paddy) for producing well milled rice by conventional milling process, some of the nutrients such as proteins, thiamine etc.are lost to a large extent. Thiamine is one of the important B-group vitamins, prolonged deficiency of which leads to physiological disease, known as beriberi. Hence it is desirable to develop post harvest processing methods for retaining nutrients during milling process, without compromising on the sensory and cooking characteristics of rice.

There is also need for development of a process for producing foods with low glycemic index (GI), for consumption by the diabetic subject .It is estimated that the number of humans with diabetes in the world has been around 171 million and has been

2020200060 03 Jan 2020 attributed to about 3.2 million deaths per annum. It is estimated that humans with diabetes is set to double by the year 2030. There are two forms of diabetes.

• Type 1: People with this type of diabetes produce very little or no insulin. People with type 1 diabetes require daily injections of insulin to survive.

• Type 2: People with this type of diabetes cannot use insulin effectively. The majority of people suffering from diabetes have the type 2 form. Although they do not depend on insulin for survival, about one third of sufferers need insulin for reducing their blood glucose levels. People with type 2 diabetes can sometimes mange their condition with lifestyle measures alone, but oral drugs are often required, and less frequently insulin, in order to achieve good metabolic control. Most people with type 2 diabetes have no symptoms and are only diagnosed after many years of onset.

Diabetes can lead to coronary artery disease, peripheral vascular disease, neuropathy, retinopathy and diabetic coma. The important non-pharmacological diabetes treatment involves healthy diet and physical activity. Insulin resistance can advantageously be reduced by consumption of diets high in protein, fibre and with low glycemic indices.

The glycemic index (GI), which is an indication of the effect of a particular food product on a person’s blood sugar, is the area under the curve (AUC) of the glucose response to a carbohydrate containing food compared to a specific glucose dose. The development of post harvest process for producing food products with low glycemic index is desirable because

a. Meals containing low GI foods reduce both post prandial glucose and insulin response.

b. Animal studies suggest that incorporating slowly digested starch into the diet delays the onset of insulin resistance.

c. Epidemiological studies suggest that a low GI diet is associated with reduced risk of developing non-insulin diabetes in men and women.

Normally processed rice with medium or high G.I., provide readily available starch to the consumer. More particularly, when these products are consumed, the starch can readily be

2020200060 03 Jan 2020 digested which in turn raises the Gl.Processed rice is classified according to its response release of glucose upon digestion. A GI value < =55 is considered as low GI, while GI of 56 -70 as medium and that above 70 is considered as high GI products. (Lang 2003) Certain varieties of rice when parboiled or under milled have low GI. But consumers have to compromise on the sensory qualities such as palatability, texture, mouth feel and loss of nutritional constituents such as protein and thiamine.

Rice being a staple food for the bulk of the world population, it is hypothesized that consumers will continue to consume rice irrespective of the consequences of a high glycemic index diet. Thus, it is desired to have rice that has an acceptable texture and flavor but does not result in a comparatively high GI when consumed. In particular, it is desired to have table rice (suitable for consumption as cooked rice) and by products (broken rice) for use as rice flour that has reduced levels /forms of readily available carbohydrates. It is most preferred if the grain or flour does not result in an elevated GI. Generally a GI below 55 is considered to be desirable with lower numbers considered even better (based on GI of glucose=100).

The GI for various milled rice and corresponding brown rice is presented in Table 1 (based on GI of glucose =100)

Various known rice varieties have been analyzed to determine the GI. Prior to processing many grains demonstrate an acceptable GI. After processing most of the rice grains have a significantly higher GI. Lor this reason, it is desired to have a rice constituent that can be processed and does not result in a significantly increased GI.

Another constraint is that many rice varieties which have a low GI have undesirable cooked grain texture mouth feel and taste. Quiet often, such rice varieties when cooked are too sticky and do not have a good mouth feel, particularly in the freshly harvested form. It is desirable to produce low GI product, particularly selecting a naturally aged grain. Additionally, some rice varieties after processing are not nutritionally complete because they are comprised primarily of starch and contain low amounts of protein and fibre (both insoluble fiber, and soluble fiber).

Most rice varieties after processing have desirable carbohydrates and flavor, but result in an elevated GI. It is desired to have a rice variety whereby the protein content is high and other nutrients are retained with an acceptable flavor but with low GI.

There are some rice varieties that have a lower GI. Most of these rice varieties are parboiled and are not acceptable in terms of texture and flavor to majority of the rice consuming population particularly raw rice customers.

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Rice being a staple food in many countries, it would be desirable to produce a well milled rice and by products that would have a low GI and relatively high protein, while not compromising on the nutritional and culinary characteristics, including color, texture, flavor and nutrients like protein and thiamine.

It is desired to have rice and rice products that includes the health benefits of low GI and still has a desired texture and flavor. This has been shown possible in the present investigation and a commercially viable process has been evolved.

PRIOR ART

There have been a few studies on the consumption of rice and the resultant GI in many parts of the world and lot of variation have been recorded However not much data is available on the texture, flavor and nutrition while looking for a low GI rice product. A few studies attempted to relate variation in the G.I of rice to the differences in the properties of starch present as amylose, (Goddard etal. 1984, lulino, B.O. and Goddard, M.S. 1986 Miller.etal 1992).Though many studies have been carried out on the physicochemical responses resulting from paddy varieties as well as treatment and processing conditions, these have not been related to their responses to GI.

A few processes for producing food products obtained from wheat, barley, com, oats, etc with low GI are available, but literature data on post harvest processing to get well milled rice to get low GI foods are not available.

Different hydrothermal treatments have been developed to bring about desirable cooking qualities in rice. For example, Normand et al (1966) have developed a process heating paddy or milled rice in sealed cans to impart aged rice characteristics to rice. The treatment comprise heating paddy or milled rice at 38oC for 40days or 65oC for 63 hours, or milled rice held at 70oC to 160oC for 30 minute to 64 hours or holding fresh paddy in closed can at 90-110°c for 2-8hrs.

El-Dash et al (1966) studied the effect of steaming of brown rice for 1-20 minutes at 118oC and 1.94 kg/ cm They reported that steaming results in controlling rancidity and inactivates lipase activity. They reported that steaming of brown rice improved storability of brown rice. Similarly Robert et al (1949) reported lipase inactivation in steam blanched rough rice (paddy).

Desikachar et al (1969) have developed a process of steaming freshly harvested paddy for 15-20 minutes targeted to obtain rice with aged rice qualities such as reduced

2020200060 03 Jan 2020 solid loss during cooking, reduced loss of alcohol precipitable solids in gruel and gruel viscosity, pastiness, retention of opacity of raw milled rice, increase in volume expansion, and improved storability in under- milled rice and the resultant bran.

Feller et al (1978) reported steam treatment for reducing stickiness in cooked rice. Biswas et al (1969) reported improved milling quality of steamed paddy. Yap et al (1988) reported undesirable yellow color in all the varieties of rice, when heated above 60oC. Several studies have been carried out on the status of starch in parboiled rice (Billiadeis, et al, 1993 Mahanta and Bhattacharya 1989, Unikrishnan and Bhattacharya 1989) .All these studies were carried out on rice varieties with varying amylose content and parboiling, (hydrothermal treatment of soaked paddy).From these studies of thermal degradation of starch under high steam pressure also gave hint that under these conditions parboiling might be inversely related to amylose content of the variety and concluded the thermal break down of starch may also play a big role in cooking behavior of parboiled rice, especially in low amylose varieties after high pressure steaming. This also resulted in canned parboiled rice with low solids loss, Thus the relationship was shown to exist between paddy variety, its starch amylose level and hydrothermal processing .However these studies did not point out the appropriate conditions of processing ,amylose content as well as relate them to the resultant GI values.

Goddard et al (1984) and Juliano and Goddard (1986) studied the influence of amylose content of rice varieties on the glucose and insulin responses of cooked rice. They inferred that cooked rice of intermediate and high amylose content leads to low blood glucose and insulin responses. But the data on nutritional and sensory characteristic of rice, as well as a method to process the same to obtain low GI rice, was not carried out. The report on high or intermediate amylose rice varieties GI indicated that the glucose response is not influenced by the amylose content alone, but may be due to complex interaction among various constituents of rice and physicochemical changes brought about by processing.

A patent has been granted to Arndt, et al (2004), discloses a US patent no. 6,761,923 wherein they claim a process and composition to produce a food product comprised of Prowashonupama barley by extrusion at high temperature to cook and form a product, by which when consumed by humans reduces the rapidly available glucose by at least 5% and does not contribute to significantly elevated GI in a host. Wolt, et al (2004) discloses a US patent number 6,706,305 a low GI baked bread product from wheat flour and a grain seed source of soluble fibre and a processed source of soluble fibre.

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It is evident that most of the post harvest hydrothermal treatment technologies reported on rice processing, as cited above, is targeted at obtaining rice with accelerated aging, improved cooking quality, a milling quality and obtaining parboiled rice. Parboiled rice and brown rice are not preferred by all sections of consumers for their appearance, color, texture, cooking and sensory characteristics. In the present invention an improved post harvest hydrothermal technology is described, where in specific rice cultivar with relatively high protein and intermediate amylose contents is subjected to steaming at appropriate moisture to obtain well milled rice and rice products thereof. This processed rice marked/designated as Sona Pearl® with protein content of at least 8%, GI of < 55%, and thiamine content of at least 3 ppm, with improved cooking quality in terms of texture, color, volume expansion and improved shelf life has been developed.

FIELD OF INVENTION

The present invention relates to post harvest processing of selected varieties of paddy when processed by the evolved hydrothermal treatment will result in milled rice and products thereof which retains relatively high protein content and dietary fiber than raw rice. The resultant product by virtue of specific hydrothermal treatment possesses relatively low GI and the resultant Sona Pearl® rice, and the Sona Pearl® rice flour and the other rice products, so processed from the by product broken rice, which are designed to inhibit or possibly prevent an elevated GI when such products are consumed. The resultant treated paddy when under-milled will have a relatively higher dietary fibre and products thereof with lower GI.

SUMMARY OF INVENTION

The present invention relates to a process for using selected varieties of non-basmati paddy to form product rice called Sona Pearl®, and rice products from the by products (broken rice ) with high protein and low glycemic index. As used herein, the term product rice and by product is not limited to rice alone but refers to other products derived from the by product of the process such as broken rice and various dishes (food products) from the same.

The selected paddy grain will be such that the protein content will be at least 8 % and the dietary fibre of around 3%.Additionally it has been observed that aged (old) rice is better for achieving lower GI in the resultant processed product (rice).

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In one embodiment, the preferred method of the present invention involves processing the paddy by hydrothermal treatment to obtain optimum levels of response in the physicochemical properties and nutritional composition of the processed rice.

In another embodiment, the invention is directed to varieties of rice useful for making low GI rice flour from the broken rice so obtained from the hydrothermal treated paddy which can be used for preparation of different extruded products i.e. vermicelli with low GI. The invention is also directed to retain the inherent nutritional properties to an extent possible and also to obtain the desired texture and culinary properties in cooked rice.

As mention earlier, the Sona Pearl® rice having an amount of total dietary fiber equal to at least 2%, an amount of protein equal to at least 8%, an amount of thiamine of at least 3 ppm and GI of less than 55% has been prepared after the suggested hydrothermal treatment.

The resultant Sona Pearl® rice food product is advantageous because, when consumed by diabetic subjects an elevated GI is not contributed to and may even be inhibited as the release of glucose is slowed down Also, the food products will be nutritionally advantageous, whereby the food product will comprise sufficient amount of protein, thiamine and dietary fiber. The resultant food product is also unique in that the GI in the Processed rice will not become elevated as a result of process, whereas, many other type of rice will have an elevated GI after processing.

Another advantage is that cooked rice from such processed Sona Pearl® rice will have a desirable texture and mouth feel, so that even raw rice eaters will relish the same.

Sona Pearl® rice is process identity preserved rice, processed out of selected paddy of appropriate age, relatively high in protein and fibre (soluble and insoluble fiber). The process results in higher nutritional value level of Sona Pearl® rice, while maintaining an acceptable texture and cooking properties even from milled rice.

DETAILED DESCRIPTION WITH EXAMPLES

The present invention relates to a process which involves identification of specific rice cultivars (Sona masoori) based on their amylose content and also relatively higher protein content Selection of paddy, (Flow chart No.l). Precleaning, Imparting hydrothermal treatment (Flow Chart II&III) Followed by hulling and Polishing Flow chart (III&IV).

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Process procedure -I

On receipt of the consignment, samples are drawn as per quality plan and the same will be checked in the laboratory for the parameters of raw materials specification and chemical composition./ amylose, protein and fiber content).If the product is found to conform to the specification, the same is accepted.

The raw material is unloaded after checking the condition of the vehicle and the packing. The supplier-lot- and batch number is now allotted and recorded and stored in the designated area. The bags are stacked on tarpaulins and covered to avoid cross contamination. The storage godowns do not allow the entry of birds and rodents.

Process procedure -II

Selected paddy is sent to Precleaner where dust, bigger particles like jute threads, foreign matters are removed. Then, paddy is discharged into an aspirator, which removes the lighter particles like dust, paper bits, etc. From here, paddy is conveyed through a bucket elevator to the storage tanks. From the storage tanks, paddy is taken to the steaming tanks and the paddy is steamed as per specified protocol (Flow chart II& III). Moisture is recorded after steaming and then unloaded into the dryer section and dried. The moisture content is monitored during unloading, circulation and on post drying. When the moisture is found to be within acceptable limits and paddy is directed and stored in silos. Care is taken to ensure that the paddy is segregated batch wise and stored in different silos.

The steamed and dried paddy is left for a minimum of 24 hours in the silo, before further processing.

Finally the treated paddy is milled as indicated the flow chart IV and V the broken and head rice is separated as per Flow chart VI.

Process procedure -III

Before taking the paddy for Hulling from the silos, the moisture content is monitored and recorded. The paddy is taken to classifier where dust, bigger particles like jute threads, foreign matters are removed. From this point, paddy is conveyed to de-stoner where stones and stone bits are removed. Paddy is then taken to huller where the husk is removed. The percentage of brown rice to the paddy is measured and recorded. The paddy is conveyed through the bucket elevator to the paddy separator where the brown rice is separated from paddy grains. The paddy grains are guided back to the Hullers. The thick grains in the brown rice are removed through the Rotosort ID. The bran is removed as a byproduct when the rice is passed through

2020200060 03 Jan 2020 a series of 3 polishers, where the optimum polishing conditions are standardized. The bran with its high fat content which is prone to microbial contamination is stored separately and dispatched within 48 hours. The broken rice which is another byproduct in each stage is monitored for corrective process actions. The rice then passes through the rotosort 2D and the immature grains are separated.

Next, the rice is taken to wet polisher known as “silky polisher” where a measured quantity of water jet is directed to the rice to wash the bran layer adhering to the rice. Water jet flow and moisture content are monitored. The water used in silky polisher is monitored for both microbial and chemical contamination as per the foods safety plan. From there, rice is taken to indent cylinder for the removal of broken rice. The indent cylinder is a length grader, which has got special dent to remove broken rice from the good quality rice. Finally the good quality rice is taken to the head rice storage bin.

Regular in-process checks are carried out to maintain the quality of the product as well as to monitor the milling performance. The moisture content before and after the process is measured to ensure that it is within limits.

Finished product is fumigated with approved fumigants to avoid infestation before packing into the pouches. After the completion of fumigation process, the final product is aerated before packing.

The resultant product (as shown in fig.01) when consumed does not lead to elevated glucose response and is suitable for humans with hyperglycemia. Additionally the resultant milled rice will give a volume expansion of 4 to 5 times when cooked with 2 to3 time’s volume of water. (Please see Fig. 02) comparison of CMR (Commercially milled rice) with a volume expansion of 2.5 to 3 times. The resultant cooked rice (shown in fig.02) will have an acceptable taste and texture as shown in table no 05 of well milled rice. The method is initiated by identifying rice cultivars that differs from other rice cultivars in that it has comparatively higher percentage of amylose content, dietary fiber and protein content which makes it ideal for producing milled rice and rice products thereof with low GI by virtue of specific hydrothermal treatment. The following examples are presented to further illustrate and explain the present invention and should not be construed as limiting in any regard.

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Example 1. Hydrothermal treatment of selected rice varieties and evaluation of GI value.

The rice cultivars with intermediate amylose content (20 to 28%) were procured with a moisture content of 10-12 % and precleaned to remove organic and inorganic foreign matter, and stored for the desired period(about six month or more) The paddy was treated hydrothermally in lots of 4-6 tons in tanks. The hydrothermal treatment for Sona masoori paddy variety was subjected to varying degrees of hydrothermal treatment and the resultant data on GI is presented in table 2.

The hydrothermally treated paddy (Sona Pearl-1) was discharged from tank to the hot air drier and circulated for 1 hour. The moisture of the paddy was brought down to 12% under circulation by hot air at an air temperature of 75oC and paddy temperature of < 50oC. The dried paddy was rested for 24 hours and milled in three stages. The paddy was passed through paddy cleaner to remove foreign matter. The paddy was shelled in sheller (Buhler Topstar) to obtain brown rice. The brown rice was redirected to paddy separator to remove any paddy in brown rice. The brown rice is passed through sorter to remove admixture (thick grains). Brown rice so obtained was polished sequentially to remove bran in three stages to get under-milled rice with 2% degree of milling in first stage, 2% degree of milling in second stage, and 3% degree of milling in third stage (total of 7%). The resultant milled rice, designated as “Sona Pearl-1 was subjected in vivo GI tests.

To determine a foods GI rating, measured portions of the food containing 50grams of carbohydrate were fed to 10 healthy people after an overnight fast. Finger prick blood samples were taken at 15-30 minute intervals over the next two hours. These blood samples were used to construct a blood sugar response curve for the two hour period. The area under the curve (AUC) was calculated to reflect the total rise in blood glucose levels after eating the test food, in a period of 2 hrs.

The GI rating (%) was calculated by dividing the AUC for the test food by the AUC for the reference food (same amount of glucose) and multiplying by 100. Glucose was used as a standard reference food for reducing the confounding influence of differences in the physical characteristics of the subjects. The average GI rating s from all the ten subjects was reported as the GI of test food.

GI was also tested for all the rice varieties. The results of this analysis are shown in table no.03.

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Example 2 Post harvest treatment of rice cultivars to produce milled rice with improved nutritional and cooking quality.

Five rice varieties viz., IR-64, Jaya, Ponni, Sona Pearl®, Basmati were compared with two samples prepared according to the process of the invention, namely Sona Pearl® -1 and Sona Pearl® -2 (Table. No. 02) and the data on GI is presented in (Table.03). The resultant milled rice were tested for proximate components such as moisture, proteins, total fat, carbohydrate, crude fiber, energy, starch and dietary fiber by standard test methods. The minerals of the milled rice i.e., phosphorous, sodium, potassium, calcium and iron contents were analyzed by adopting standard methods. The amino acids like lysine, and Methionine levels in the sample were estimated by standard method. The thiamine content of Sona Pearl® rice as prepared from process of invention designated as “Sona Pearl® -2” was estimated by standard AO AC method. Data presented in table -4.

The cooking qualities such as color, odor, stickiness, volume expansion and shelf life of cooked rice (as shown in figure no.01) of all the rice varieties as prepared from the process of invention were analyzed by standard procedure. All the rice varieties were cooked in 2.5 times (v/v) of water for 30 minutes in graduated glass tube in a rice cooker. The volume of cooked rice were recorded and analyzed for other sensory and organoleptic characteristics and as shown in table 05.

1. The rice obtained from paddy variety Sona Pearl® has recorded higher energy value of 365.66Kcals when compared to other rice varieties tested.

2. Sona Pearl® -2 has recorded the highest dietary fibre value of 2-4%. Dietary fibre rich cereal has better food value along with higher proteins and other minerals and amino acids.

3. The crude fibre content of Sona Pearl® rice is also relatively higher (by 0.35%) when compared to other varieties.

1. Interestingly, the raw milled rice of Sona Pearl® (as shown in figure no 01) showed low GI of 51%. The milled rice obtained from Sona masoori rice variety as prepared from process of invention namely Sona Pearl® -1 and Sona Pearl® -2 have recorded low GI values of 55% and 44% respectively.

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2. The Sona Pearl® rice processed by the process protocol (as shown in figure no.01) Sona Pearl® -2 recorded the lowest GI among the different rice varieties tested.

3. The rice as prepared from the process of invention from rice variety IR-64 has recorded a GI of 52%.

4. Non pharmacological diabetic management is generally achieved by use of foods with low GI and low glycemic response. As shown in the Table 03, the three samples of Sona masoori viz, Sona Pearl®’ Sona Pearl® -1 and Sona Pearl® -2 have recorded low GI, which makes it suitable for humans with hyperglycemia.

5. Hyperglycemia in diabetic patient is considered a risk factor for developing micro vascular complications which may lead to death. GI values gives a measure of glycemic response of the food products hence ideal for selecting food products for humans suffering from type II diabetes and humans who wish to reduce the digestible carbohydrate intake.

6. The starch contents of Sona Pearl® -2 and Sona Pearl® recorded low value of 76.91% and 77.92% respectively when compared to other rice varieties.

7. Sona Pearl® -2 also recorded fat content of < 0.98%.

8. Rice varieties contain fairly rich amounts of these minerals, which are important for the metabolic activity of human beings. Among the seven rice cultivars Sona Pearl® -2 has recorded comparatively higher mineral contents except potassium content but rich in calcium content, which is very important nutrient in the metabolism of human beings.

9. Sona Pearl® -2 also recorded thiamine content of 3 ppm which is considerably higher compared to that reported for normal milled raw rice.

CROSS REFERNCE TO RELATED APPLICATIONS

The present application pertains to selection of rice cultivars based on their protein and amylose content and processing them in such a way as to render them suitable for consumption for diabetics and obese subjects

References:

1. Arndt, E.A., Sambasiva, C.R., and Sarath, K.K. 2004. Method and composition related to low glycemic index foods. US patent No. 6761923.

2. Biswas, D.P., Written, F.T., Faulkar, M.D., and Miller, M.E. 1969. Affects of high temperature and moisture for predconditioning rice for milling. Rice J., 72(4), 31.

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3. Billiaderis C.G, Tongai .J.R., Perez C.M., and Juliano, B.O. 1993.Thermophysical properties of milled rice as influenced by variety and parboiling method. Cereal Chemistry 70,512-516.

4. Desikachar, H.S.R., Sowbhagya, C.M., Viraktamath, C.S., Indudharaswamy, Y.M., and Bhasyam, M.K.1969. Steaming of paddy for improved culinary, milling and storage properties. J.Food.Sci. Tech. 6.1.

5. El-Dash, A., Kubuuka, A., and Brazil, G.K.1978. Improving the nutritional value of rice: Effect of steam treatment on storability of brown rice. Cereal Foods World. 23(8), 488.

6. Fellers, D.A., and Deissinger, A.E. 1978. Steam treatment of rice paddy as a means of reducing stickiness. Cereal Foods World, 2(8): 488.

7. Ginzburg, M., and Popov, M. 1972. The effect of hydrothermal processing of rice on the quality of rice groats. Mul. Ele. Pro (USSR), 38(7):25 (Cited in Food Sci and Tech abstracts (FSTA), 1973, 5:4M416.

8. Goddard, M.S., Young, G.M.S., and Marcus, R. 1984. The effect of amylose content on insulin and glucose responses to ingested rice. The American J. Clin. Nut. 39, 388-392.

9. Gusev, P.L., and Kuzmina, O.V. 1972. Hydrothermal processing of rice. Mul. Ele. Pro (USSR), 38(9):19 (Cited in Food Sci and Tech abstracts (FSTA), 1973, 5:4M416.

10. Juliano, B.O. 1990. Rice grain quality: problems and challenges. Cereals Foods World, 35(2): 245-253.

11. Juliano, B.O. 2003. Nutritive value of rice and rice diets In “Rice Chemistry and Quality”. Chapter. 4, pp 133.

12. Juliano, B.O., and Goddard, M.S. 1986. Cause of varietal difference in insulin and glucose responses to ingested rice. Qual. Plant Foods Hum. Nut. 36, 35-41.

13. Lang.V. (2003) Development of a range of industrialized cereal based food stuffs, high in slowly digestible starch. Chapter 17,pp 477-504.

14. Mahantha.C.L.and Bhattacharya.K.R..(1989) Thermal degradation in Parboiled rice Starch Starke 41:91-94.

15. Miller, J.B., Pand, E., and Bramall, I. 1992. Rice: a high or low glycemic index food ? Am. J. Clin. Nut, 56, 1034-1036.

16. Normand, F.J., 1966. Process for aging rice artificially. US patent 3258,342.

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17. Normand, F.I., Hogan, J.T., and Deobald, H.J. 1964.Improvement of culinary quality of freshly harvested rice by heat treatment. The Rice Journal (December), 7-11.

18. Roberts, R.I., Van Atta, G.R., Hunter, I.B., Houston, D.F., Kester, E.B., and Olcott, H.S. 1949. Steam blanching of fresh rough rice curbs spoilage by fatty acids. Food Ind. 21, 1041.

19. Stipe, D.R., and Miller, M.P.1975. Effect of steaming, drying and tempering conditions on milling yield of rough rice. Rice J. 78(7), 58.

20. Unikrishnan,K.R.,and Bhattacharya.K.R.(1989) Reviving of pressure parboiling process by the use of low amylose varities of paddy .Indian Food Industry ,8,2528.

21. Wolt, M.J., Arndt, E.A., Hinchik, J.R. 2004. Low glycemic index bread. US patent No. 6,706,305.

22. Yap, A.B., Juliano, B.O., and Perez, C.M. 1988. Artificial yellowing of rice at 60oC. Paper presented at the 11^th ASEAN technical seminar on grain post harvest technology, Kuala Lumpur, August 23^rd to 26^th.

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Table 1 Glycemic index of milled rice and rice products

SI. No.	Food	Glycemic index	Reference
1	Calrose white(milled)rice	82 + 13	1
2	Calrose brown rice	87 + 8	1
3	Pelde white	93 + 11	1
4	Pelde brown rice	76 + 6	1
5	Doongara brown	66 + 7	1
6	S unbrown Quick	80 + 7	1
7	Waxy rice	88 + 11	1
8	Rice cakes	82 + 11	1
9	Milled parboiled rice	47 + 3	2
10	Milled parboiled rice (intermediate amylose)	54+1	2
11	Milled rice (waxy low amylose)	88+3	2
12	Instant milled rice (intermediate/ high amylose)	91+4	2

Table 2 Hydrothermal treatment protocol

Rice variety	Treatment protocol	Steam pressure ()kg/Cm2)	Steaming time (min)	Holding time (min)
Sona masoori	Untreated	Nil	Nil	Nil
Sona masoori	Sona Pearl -1 (Sona masoori new)	10	20	15
Sona masoori	Sona Pearl - 2 (Sona masoori aged)	10	35	15 to 30 min.

Table 3 Glycemic index of milled rice products tested

Rice Variety	GI
Sona masoori	51
Sona Pearl ® 1 (Sona masoori new)	55
Sona Pearl ® 2 (Sona masoori aged)	44
IR-64	'52
Jay a	68
Ponni	59
Basmathi	63

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Table no 04 PROXIMATE CONSTITUENTS OF DIFFERENT RICE VARITIES

r 0	Constituents	IR-64	JAYA	PONNI	Basmati	Sona pearl	Sona Pearl-1	Sona pearl -2
1	Moisture(%)	10.01	10.495	9.02	9.19	9.12	10.01	10.07
2	Protien(%)	6.44	7.87	9.35	7.52	9.52	10.02	10.09
3	Total Fat(%)	0.69	0.7	0.68	0.67	0.8	0.89	0.98
4	Carbohydrates(%)	82.39	80.33	80.33	82.34	80.1	76.25	77.57
5	Crude fibre(%)	0.31	0.37	0.25	0.17	0.35	0.32	0.33
7	Energy(K cal)	361.51	359.08	364.82	365.47	365.55	353.09	359.46
8	Starch (%)	81.66	79.54	77.94	81.22	77.92	77.41	76.91
9	Dietary fibre (%)	1.5	1.4	1.8	1.4	2.4	2.4	2.4
0	Phosphorous ppm	0.07	0.07	0.09	0.06	0.09	0.145	0.11
1	Sodium ppm	131.74	31.95	91.91	51.09	58.5	84.21	109.92
2	Potassium ppm	210.05	483.82	842.79	284.09	638.02	567.82	497.62
3	Calcium %	0.18	0.17	0.14	0.13	0.18	0.2	0.23
4	Iron mg/100gm	3.999	4	5	2.999	2.999	3.99	4.99
5	Lysine %	0.2	0.22	0.19	0.18	0.19	0.17	0.16
6	Methioninie%	0.14	0.15	0.12	0.12	0.1	0.1	0.1

Table: - 05 COOKING CHARACTERSTICS OF BASMATI AND NON BASMATI RICE.

PARAMETERS	SORNA PEARL	IR-64	JAYA	PONNI	BASMATI
Colour	White	Light yellow	Light yellow	White	White
Odor	Highly acceptable	Acceptable	Acceptable	Acceptable	Highly acceptable
Stickiness	Absent	Sticky	Sticky	Slightly sticky	Absent
Volume expansion	4.5	3.3	3.7	4.0	5.0
Texture	Discrete	Non discrete	Plumpy	Discrete	Discrete
Stability	Stable	Non stable	Non stable	Stable	Stable

2020200060 03 Jan 2020

Table no: 06 Comparison of Sona pearl rice with commercially milled rice

PARAMETERS	SONA PEARL DIA RICE (lOOg)	COMMERCIALLY MILLED RICE (lOOg)
Protein, g	10.09	6-8
Dietary Fibre, g	2.40	1.4-1.8
Total Carbohydrate, g	77.57	80-83
Energy (Cal)	360	360
Iron, mg	4.99	1-3
Calcium, mg	0.23	130-180
Vitamin BI, mg	0.44	0.11
Lysine, %	0.16	0.16-0.2
Methionine, %	0.10	0.1-0.15
Glycemic index	40	60-80

Claims (10)

1. We claim:

   1. A method for post harvest hydrothermal treatment of paddy to retain nutrients and obtain rice with low glycemic index; wherein the method comprises the steps:

   selecting non basmati rice paddy grains with a predefined composition; wherein the composition includes amylose at least 20%, protein at least 8% and dietary fibre at least

   3%;

   precleaning the selected paddy to remove organic and inorganic foreign matter;

   storing the precleaned paddy into storage tanks for a predetermined duration;

   steaming the paddy to achieve optimal moisture content to perform the hydrothermal treatment of the paddy;

   drying the paddy to optimal moisture content in the paddy;

   circulating the paddy to reduce temperature of the paddy after drying; and segregating the steamed and dried paddy for storage in different silos, wherein the paddy is left for 24 hours.
2. 2. The method as claimed in claim 1, wherein the method includes further pre cleaning the stored paddy to remove organic and inorganic foreign matter.
3. 3. The method as claimed in claim 1, wherein the method includes hulling of the paddy to remove its husk and get brown rice.
4. 4. The method as claimed in claim 3, wherein the method includes passing the hulled paddy and rice mixture through paddy separator for separating brown rice from the paddy.

   2020200060 03 Jan 2020
5. 5. The method as claimed in claim 4, wherein the method includes passing the brown rice through a size sorter to remove thick grain.
6. 6. The method as claimed in claim 5, wherein the method includes polishing the brown rice to remove its bran layer by directing a measured quantity of water jet on the brown rice in a polisher.
7. 7. The method as claimed in claim 6, wherein the method includes passing the brown rice through an indent cylinder which has a dent to separate the broken rice to get good quality rice.
8. 8. The method as claimed in claim 7, wherein the method includes storing the good quality rice into the head rice storage bin.
9. 9. The method as claimed in claim 8, wherein the method includes fumigating the good quality rice to avoid infestation as a further step.
10. 10. The method as claimed in claim 9, wherein the method includes packing the hydrothermally treated good quality rice under predefined atmospheric conditions with Carbon dioxide or Nitrogen.