Claims:
1. A fiber fortified soft idli batter comprising psyllium husk, wherein the amount of the psyllium husk is less than or equal to 4% weight on dry basis.

2. The idli batter as claimed in claim 1, wherein it further comprises legumes selected from moong dal and masur dal.

3. The idli batter as claimed in claim 1, wherein it further comprises grains selected from rice, ragi, barnyard millet, proso millet, foxtail millet and little millet etc.

4. The idli batter as claimed in preceding claims, wherein the idli is free of urad dal.

5. The idli batter as claimed in claim 1, wherein the psyllium husk can be unprocessed or gamma radiation processed.

6. The idli batter as claimed in preceding claims, wherein the unprocessed psyllium husk is ball milled.

7. The idli batter as claimed in claim 5, wherein gamma radiation processed psyllium husk is irradiated by 25kGy gamma radiations.

8. The idli batter as claimed in claim 1, wherein it comprises 2% of radiation processed psyllium husk.

9. A method for preparation of idli batter, wherein the method comprises the following steps:
a. washing rice and legumes or other grains separately with excess water and soaking separately for 4 hours;
b. wet grinding the legumes and grains together with little water;
c. adding Psyllium and grindings lowly by adding water till the batter is nice smooth and fluffy;
d. grinding the batter of step (ii) with remaining water to obtain a smooth paste;
e. mixing the both batters of steps (iii) and (iv) well with clean spoon by adding salt.
f. fermenting at room temperature for 16 hours.

10. The method of claim 9 further comprising the step of greasing idli moulds with edible vegetable oil and steaming the fermented batter for 7 minutes.

11. The method as claimed in claim 9, wherein the psyllium husk is unprocessed.

12. The method as claimed in claim 9, wherein the psyllium husk is gamma radiation processed at 25kGy.

13. The method as claimed in claims 11, wherein the psyllium husk is ball milled.

14. A moong dal idli prepared from the batter of claim 1 wherein the batter comprises rice, moong dal and psyllium husk.

15. A multigrain idli prepared from the batter of claim 1 wherein the batter comprises rice, multigrains and psyllium husk.
, Description:
FIELD OF THE INVENTION:
The present invention relates to the preparation of idli (rice cakes) using unprocessed and/or radiation processed psyllium as a functional hydrocolloid for improving the textural properties and as a source of dietary fiber.

BACKGROUND OF THE INVENTION:
Application of dietary fiber into different food systems has become prominent nowadays, not only because of its health benefits but also due to their property to impart superior quality attribute to the final product. Idli is one of such traditional cuisine of southern India and is prepared from the batter consisting of fermented rice and urad dal (black gram, Vigna moonga). Traditionally, it is prepared using one part of whole white urad dal and three parts of uncooked rice (Idli rice or parboiled rice). The ingredients are soaked separately for minimum of five hours and then ground separately, mixed and fermented overnight. The batter then becomes double the volume is used for preparing the Idli cake. However, the traditional idli can be prepared only using urad dal which is primarily responsible for the soft and spongy texture of the finished product. Urad dal is the key ingredient in preparation of idli because the batter prepared using this legume can hold carbon dioxide released during fermentation of batter and thus makes the idli soft and fluffy. Replacing urad dal with any other legumes or dal does not give the required texture and thus the product becomes unacceptable.

Moong dal (Vigna radiata) is another legume rich in easily digestible protein and comparatively cheaper than urad dal which can be used for preparation of idli. However, the fermentation of batter prepared using rice and moong dal lacks the required consistency to get the final product with soft and spongy characteristics. Idli prepared using other legumes does not give these textural properties. Steaming moong or multigrain idli batter devoid of urad dal leads to hard and flattened idli. Replacing urad dal with low cost legumes like moong dal hampers the raising of the batter as it lacks the functional molecules?arabinogalactan and arabinoxylan.

Although addition of baking soda increases the batter volume but will not release the flavor or aromatic compounds, thus dry premixes have very low acceptance among consumers.

Sanjeev K. Soni and Dhanwant K. Sandhuin. Journal of Fermentation and Bioengineering Volume 68, Issue1, 1989, Pages52-55 reported nutritional improvement of Indian dosa batters by yeast enrichment and black gram replacement. They reported Saccharomyces cerevisiae enrichment in combination with the natural bacterial flora is the best microbial factor for standardizing the dosa fermentation. Batter types containing soybeans are most nutritious in terms of total nitrogen, protein, amylase, proteinase, and vitamin B contents, followed by mung bean batters, while the conventional black gram product is most preferred organoleptically.

C R Rekha and G Vijayalakshmi in Journal of Food Science and Technology-Mysore-48(3):329-34(2011) reported accelerated fermentation of ‘idli ’batter using soy residue okra. In this work, the authors tried reducing the natural fermentation period of 'idli 'from the conventional 14 hours to 10 hours by adding under utilized okra for the preparation of 'idli'. Black gram was partially substituted with soy residue okra in the ratio of (1:1). After 14 hours of natural fermentation, the pH and total acidity of control 'idli 'batter was 4.51 and 0.64% and that of okra fortified 'idli 'batter was 4.53 and 0.43%, respectively. The amount of CO2 released by the control and okra fortified batter was 19.7% and 33.6% respectively. The viable count of yeast and mold, lactic and mesophilic bacteria in control & okra batter increased with time reaching 9.00 & 10.34, 8.66 & 7.69, and 8.65 &9.47 log10 cfu/g, respectively at the end of 10 hours of natural fermentation. Okra fortified 'idli' was soft and spongy compared to control 'idli'.

Fermentation is an important step in idli batter preparation which not only helps in rising of batter but also provides the bacterial enzymes produced during fermentation assisted release of aromatic compounds leading to improved organoleptic properties.

Psyllium husk is one of such dietary fiber used as a thickening and stabilizing agent in food industries like in baking processes the arabinoxylan (a dietary fiber) present in psyllium and wheat entraps the CO2 released during fermentation and helps in rising of baked products like bread and muffins.

K. Deepika Shree et al., in Int. J. Curr. Microbiol. App. Sci (2017) 6 (7): 3850-3863, reported studies on exploration of psyllium husk as prebiotic for the preparation of traditional fermented food “buttermilk”. The study concluded that the probiotic butter milk can be prepared by utilizing curd, ground spices, coriander leaves, salt and Psyllium husk using equal amount of 1 percent starter culture of LAB viz. L. acidophilus and L. bulgaricus. The process of preparation of probiotic butter milk can be technoeconomically feasible, justifies the suitability of incorporation of psyllium husk in probiotic based health or functional food for commercial exploration.

Alicja Ziemichódetal., in journal of food processing in engineering, Volume 42, Issue 1 (2019), reported Seeds of Plantago psyllium and Plantago ovata: Mineral composition, grinding, and use for gluten free bread as substitutes for hydrocolloids. The aim of the study was to evaluate the physicochemical characteristics, grinding, and possibility of whole seeds of Plantago psyllium (PP) and Plantago ovate (PO) application as an alternative to hydrocolloid for gluten free bread baking. The procedure of seeds swelling was proposed, trace elements and physical properties of seeds were determined. The grinding energy of seeds and the baking of gluten-free bread with the addition of whole and grinded form of seeds was made.

In order to overcome these problems various chemical and enzymatic treatments were done for bringing desired modifications in psyllium husk.

US6248373B1 describes the application of enzymes to produce modified psyllium with improved functional properties. However, these chemical and enzymatic treatments have their own limitations for commercialization.

US20030211179A1 discloses methods of producing psyllium with improved functionality by employing a solid-state enzyme reaction. The psyllium prepared according to the process disclosed herein show improved functionality, i.e., less gel hardness can thus be readily incorporated into a wide variety of products such as food stuff, pharmaceutical compositions, animal feeds, beverages and the like.

Apart physical and chemical treatments, psyllium husks are also known to be modified by using radiations.

US7,288,225B2 discloses Ispaghula (material from the plant Plantago ovata, useful as an agent in relieving constipation, is subjected to treatment with- radiation at a dose of upto 13kGy, and preferably in the range 5-10kGy. The process appears to improve the water absorption characteristics of the ispaghula.

The present invention uses radiation processing as a physical treatment to bring modifications in psyllium, which is cost effective and overcome the limitations present in other available treatments.

The present invention describes the preparation of idli with desired textural properties using legumes other than urad dal with the addition of processed or unprocessed dietary fiber to develop a naturally fermented moong dal idli which are as soft as traditional idli. It completely eliminates the role of urad and baking soda.

OBJECT OF THE INVENTION:
It is an object of the present invention to provide a fiber fortified soft idli batter composition free of urad dal yet having desired sensory and textural properties.

It is another object of the present invention to provide a method for preparation of a fiber fortified idli free of urad dal yet having desired sensory and textural properties

It is further an object of the present invention to provide a fiber fortified moong dal or multigrain idli batter or premixes having the desired sensory and textural properties of the product.

It is an object of the present invention to provide a fiber fortified soft idli composition free of urad dal yet having desired sensory and textural properties comprising the unprocessed (ball milled) food grade hydrocolloid (psyllium).

It is another object of the present invention to provide value addition: in the form of dietary fiber, and replacement of traditional ingredient with others for an economic product, without compromising the sensory and textural properties.

BRIEF DESCRIPTION OF THE INVENTION:
Figure 1 illustrates texture profile of various idli
Figure 2 illustrates rising of the moong idli when fortified with different percentage of UPPs and/or RPPs.
Figure 3 illustrates comparison of 24h fully fermented batter of moong idli batter containing 2% RPPs with control (urad) batter
Figure 4 illustrates rise in batter volume after fermentation
Figure 5 illustrates rheological studies of unprocessed and radiation processed psyllium gel. (A) Storage modulus, (B) loss modulus (at 1.29 Hz) of psyllium gel at various concentration (3?6%). UP & RP = Unprocessed and radiation processed psyllium (25kGy), respectively.

SUMMARY OF THE INVENTION:
In an aspect there is provided, a fiber fortified soft idli batter composition comprising rice, legumes and/or grains and the fiber is psyllium husk, wherein the psyllium husk is in an amount <4% weight on dry basis.

In a further aspect of the present invention, there is provided that a method for preparation of idli batter comprising adding the psyllium husk in the grounded batter of rice, legumes and/or grains.

In yet another aspect of the present invention, there is provided a method for adding softness to idli comprising adding the psyllium husk in the idli batter.

DESCRIPTION OF THE INVENTION:
Idli: the term idli as used herein indicates a type of savory rice cake. Idli is one of the most popular and commonly used breakfast item, which is prepared from a fermented batter. In the present invention, reference to idli batter also includes the idli prepared therefrom.

The present invention is directed to soft textured idli and the method for preparation thereof.

The terminology used herein is for the purpose of describing particular various embodiments only and is not intended to be limiting of various embodiments. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" used here in specify the presence of stated features, integers, steps, operations, members, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and/or groups thereof.

Described herein is a idli batter that produces fiber fortified soft textured idli and the method for preparation thereof.

As discussed in the background idli’s without urad dal fails to provide soft textural properties. The present invention provides a fiber fortified soft idli composition comprising grains, legumes and/or grains; and psyllium husk, wherein the psyllium husk is in an amount of less than equal to 4% weight on dry basis.

Grains include but are not limited to ragi, barnyard millet, proso millet, foxtail millet and little millet etc. The fiber fortified idli comprising legumes excluding urad dal. Legumes can be used to prepare idli are selected from moong dal and masur dal.

The psyllium husk present in idli batter can be processed or unprocessed. Processed psyllium husk indicates that the idli is radiation processed.

The present invention provides a fiber fortified idli batter comprising radiation processed psyllium in an amount =4% (dry weight basis; d.w.b).

The fiber fortified idli, is both cost effective and simple to prepare. The inclusion of psyllium husk in the idli results in idli’s with high dietary fiber content.

The present inventors observed that addition of food hydrocolloids like psyllium as a suitable healthier replacement of urad dal in idli preparation. However, adding more amount of psyllium in food systems after a certain level gives an undesirable slimy or adhesive texture which makes them unpalatable. The present inventors found that the suitable amount of psyllium husk is less than equal to 4% which provides the desired structural, sensory and textural properties. Therefore, high gelling properties of psyllium husk limits its miscibility in food matrix when added in higher amounts.

In another aspect, the present invention provides a method for preparing soft textured legume idli which comprises the following steps:
1. washing rice and legumes/ grains separately at least 3 times with excess water and soaking them separately for 4 hours.
2. wet grinding the legumes and grains to obtain a smooth paste with a suitable quantity of water.
3. adding Psyllium and grinding slowly by adding water till the batter is nice smooth and fluffy.
4. further grinding legume and rice to smooth paste with remaining water.
5. mix the both batters of steps (3) and (4) well with clean spoon by adding salt.
6. fermenting at room temperature for 16 hours.
7. greasing idli moulds with edible vegetable oil and steaming the fermented batter for 7 minutes.

Similar steps are followed for preparing multigrain idli batter.

In another aspect the present invention provides a method for preparation of idli comprising adding the psyllium husk in the grounded batter of rice, legumes and/or grains.

A fermented batter can be used for the preparation of soft textured legume idli.

In an embodiment, the fermented idli batter comprises rice, legumes, salt, water and psyllium husk. wherein the psyllium husk is unprocessed and ball milled.

In an embodiment, the present invention provides a fermented idli batter comprising rice, legumes, salt, water and psyllium husk wherein the psyllium husk is gamma radiation processed at 25 kGy.

Table 1 enlists the components present in a fermented idli batter comprising psyllium husk.

Table1.Percent composition of ingredients for urad, moong and millet idli.

Percent (dry weight basis)
Urad idli Moong idli Moong idli with RPPs/UPPs Millet idli with RPPs/UPPs
Rice =50 =50 =50 =35
Moong 0 =50 =50 =25
Urad =50 - - 0
Ragiflour - - - =25
BarnyardMillet - - - =5
ProsoMillet - - - =5
FoxTailMillet - - - =5
Salt - - - 1.75
RPPs* - =4 =4 =4
UPPs* <4 <4 <4

*RPPs/UPPs=Radiation processed psyllium/Unprocessed psyllium.

Psyllium is used as a thickening and stabilizing agent in food industries. However, after a certain level of addition it gives an undesirable slimy or adhesive texture which makes the food product unpalatable. High gelling properties of psyllium husk limits its miscibility in food matrix when added in higher amounts.

For better understanding the present invention is now being illustrated by way of non-limiting examples.

Raw Materials: Moongdal, idli rice, salt and psyllium (25kGy irradiated), urad dal (Table2)

Table 2: List of ingredients andt heir amount

Ingredients Amount (grams)
Trial 1 Trial 2 Trial 3
Moong Dal(g) 150 50 600
Idli Rice(g) 450 150 1800
Salt(g) 15 5 60
Psyllium 12 4 48
Water(ml) 825 275 3300
Idlis(Nos.) 38 16 180

Example 1: Moong dal idli
Rice and moong dal was washed 3 times with excess tap water and was soaked separately 4 hours. Soaked moong dal was wet grounded initially with little water. Water was added slowly till the batter is nice smooth and fluffy. Rice was grounded separately into smooth paste with remaining water. Both the batters were mixed with clear spoon with the addition of salt; the whole batter was kept for fermentation at room temperature for 16 hours. Idli moulds were greased with edible vegetable oil and the batter were poured into the moulds and steamed for 7 minutes. Lid was opened after 5 minutes to get Moong dal idli.

Figure 1 represents the texture profile of various idli. Force (g) indicates the hardness of the sample. Hardness of the sample is proportional to the force required to compress the sample. Moong dal idli without any added psyllium was observed to the hardest (Fmax=9029g) among all other idlis. Similarly, moong idli prepared from batter containing 1%RPPs?added to the fermented batter, resulted in hard idli (Fmax=8254g; represented as Mung idli_NoPs_Ps post fermentation). This data indicates that adding psyllium after fermentation of mung idli batter will not give a soft product. In other words, psyllium has to be added before the fermentation.

Thus, it clearly shows that; fortification of psyllium has to be carried at initially stages of the batter preparation. The added fiber facilitates entrapment of carbon dioxide released during fermentation and thus creating anaerobic environment enabling better fermentation of the batter. In unfortified batter on the other hand, lacks any fiber (moong dal unlike urad dal lacks fiber) does not hold or trap the released gas and hence does not get fermented properly which eventually releases off odor. The later do retain even after steaming of the idli. Thus, softness and other sensory properties imparted to the final product is not just due to moisture holding capacity of the psyllium which is the case for many food products prepared using psyllium.
Example 2: Moong dal idli comprising unprocessed psyllium husk
Rice and moong dal was washed 3 times with excess tap water and was soaked separately 4 hours. Soaked moong dal was wet grounded initially with little water. Unprocessed Psyllium dose was added to the wet grounded batter of moong dal and grinding was continued. Water was added slowly till the batter is nice smooth and fluffy. Rice was grounded separately into smooth paste with remaining water. Both the batters were mixed with clear spoon with the addition of salt; the whole batter was kept for fermentation at room temperature for 16 hours. Idli moulds were greased with edible vegetable oil and the batter were poured into the moulds and steamed for 7 minutes. Lid was opened after 5 minutes to get soft and fluffy moong dal idli.

The textural property of the idli which is indicated by Force (g) imparted by probe is found to be 3492 and 4232 g for moong dal idli containing 2 and 4% unprocessed psyllium husk, respectively. Both 2 and 4% UPPs fortification resulted in softer idli than the moong idli without psyllium. However, within 2% and 4% UPPs fortification, former resulted in softer idli than the latter. Also, idli with 2% UPPs fortification resulted in better raising than 4% (Figure 2).
Example 3: Moong dal idli comprising 25 kGy gamma radiation processed psyllium husk
Rice and moong dal was washed 3 times with excess tap water and was soaked separately 4 hours. Soaked moong dal was wet grounded initially with little water. Psyllium irradiation at lab scale was done in GC5000, dose was added to the wet grounded batter of moong dal and grinding was continued. For large scale commercial food irradiator containing Co60 as radioactive source can be used. Water was added slowly till the batter is nice smooth and fluffy. Rice was grounded separately into smooth paste with remaining water. Both the batters were mixed with clear spoon with the addition of salt; the whole batter was kept for fermentation at room temperature for 16 hours. Idli moulds were greased with edible vegetable oil and the batter were poured into the moulds and steamed for 7 minutes. Lid was opened after 5 minutes to get soft and fluffy moong dal idli.
Softness of the moong dal idli comprising 2% of 25 kGy gamma radiation processed psyllium husk was (F = 2536 g) found to be nearer to the urad dal idli.
Example 4: Preparation of Moong dal idli comprising some other amount of gamma radiation processed psyllium husk
Moong dal idli comprising 1% and 4% of gamma radiation processed psyllium husk showed a force value range of 3000?3300g (Fig.1). Which indicates that adding gamma radiation processed psyllium husk has increased the softness of idli when compared to moong idli without psyllium (F=9029 g).
Table 3 represents the proximate analysis, moisture, dietary fiber content and percent acceptability of different idli’s prepared. Figure 2. represents the raising of the moong idli when fortified with different percentage of UPPs and/or RPPs. Among all others, idli raising during steaming is found to better (2.1 cm) with fortification of UPPs and RPPs at 2% level; followed by the 4% RPPs fortification (1.7 cm). However, 4% UPPs fortification didn’t lead to raise in the idli volume (1 cm). Although, idli rising in moong batter without psyllium is seen (1.6 cm), but this resulted in harder product (F max=9029 g; Figure 1).

Further, comparison of 24h fully fermented batter showed that moong idli batter containing 2% RPPs and control (urad) batter is more uniform in nature. Whereas, moong idli batter containing 0 and2% UPPs is non-uniform, where settling of water at the base of batter was observed (Figure3).
Further in Figure 4, it has been observed that the rise in batter volume after fermentation is significantly less for other hydrocolloids like Acacia Gum (AG) and Locust Bean Gum (LBG). Rise in the batter volume after fermentation is an essential parameter. Although for GG fortification, the raise in the batter volume is as significant as RPPs. However, uniformity of batter upon GG addition is compromised which is evident from presence of water layer at the bottom of the container (Figure 4; same phenomenon can be seen with LBG). Also, idlimade out of these batters resulted in hard idli for LBG and AG fortification. Thus, it shows that adding any hydrocolloid during batter preparation by a skilled person will not replace the urad dal properties, which is required for making soft and puffy idli’s.

Table 3. Comparative analysis of all the types of idli.

%Moisture %Ash %Protein % Dietary fibre (d.w.b)* % Available carbohydrate (f.w.b)$ Force (g) % Acceptability
Urad idli 68.8 0.72 12.2 7.14 70.4 1810 100
Moong idli 69.7 0.7 11.9 5.6 75.4 9029 60
Moong idli_RPPs/UPPs (1-4%) 60-65 0.7 12.2 7.14 70.6 2536-3332 95-99
Millet idli 50.4 0.75 12.1 8.2 - 2800 85
*d.w.b=dry weight basis $f.w.b=fresh weight basis

ADVANTAGES OF THE INVENTION:
Main advantage of the invention is to use low cost legumes like moong dal in the preparation of idli without compromising its sensory attributes. Application of unprocessed and/or radiation processed psyllium as a constituent enabled to use of legumes other than urad dal for preparation of idli without affecting its textural property. Further, the core ingredients used in present innovation allowed natural fermentation to take place there by increasing the organoleptic properties of the final product.