Description:
FIELD OF INVENTION
The present invention relates to an aerosol generating substrate, which is substantially free from tobacco and method of making the same.

BACKGROUND OF INVENTION
Electrically heated aerosol generating products consists of an aerosol-generating article and an aerosol-generating device wherein the aerosol-generating article has an aerosol-generating substrate, cooling segment and the mouth end segment. The aerosol-generating device comprises a power source and an electronic controller.
Electrically operated aerosol generating products for delivering actives are well known in the art. In this kind of products, the aerosol generating substrate is heated to the predetermined temperature to generate aerosol.
WO2020167805A1 relates to the use of reconstituted Cocoa Husk to make solid aerosol generating substrate which can also be used as a filler agent in tobacco based substrate as well as non-tobacco based nicotine based substrate.
WO2020207733A1 relates to an aerosol generating film consisting of polyhydric alcohol (composition at least 25% w/w), cellulosic base film forming agent (composition at least 10% w/w) and having and within the aerosol generating substrate the exposed surface are of the film is 5 sq. mm per mg of aerosol generating substrate.
There is still a long felt need in the art to develop an aerosol generating substrate which is substantially free from tobacco. The present inventors have surprisingly developed an aerosol generating substrate which ameliorates the aforesaid shortcomings of the prior art and is substantially free from tobacco.

OBJECTS OF THE INVENTION
It is an object of the present invention to provide an aerosol-generating substrate that overcomes the drawbacks of prior art.
It is another object of the present invention to provide an aerosol generating substrate which is substantially free from tobacco.
It is another object of the present invention to provide a method for preparing a substantially, tobacco-free aerosol generating substrate.

SUMMARY OF THE INVENTION
According to an aspect of the present invention there is provided an aerosol generating substrate, which is substantially free from tobacco.
According to another aspect of the present invention there is provided a method for preparing an aerosol generating substrate which is substantially free from tobacco.

DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.
Accordingly, those skilled in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the scope of the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.
It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, steps or components but does not preclude the presence or addition of one or more other features, steps, components or groups thereof.
The term ‘aerosol-generating device' as used herein relates to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-forming substrate forms a part of an aerosol-generating article.
The term 'aerosol-forming substrate' as used herein relates to a substrate capable of releasing volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. An aerosol-forming substrate forms a part of an aerosol-generating article or smoking article.
The terms 'aerosol-generating article' as used herein refer to an article comprising an aerosol-forming substrate that can release volatile compounds that can form an aerosol.
The term ‘aerosol-generating system’ as used herein is a combination of an aerosol-generating device and an aerosol-generating articles for use with the device.
The term “reconstituted” as used herein refers to a material formed by a process in which a ground plant feed stock is mixed with water and other ingredients to make a homogeneous slurry The slurry is then casted into sheet through any suitable process.
The term 'sheet' as used herein denotes a laminar element having a width and length substantially greater than the thickness thereof.
The term 'gathered' as used herein denotes that the sheet of reconstituted material is pleated, convoluted, folded, or otherwise compressed or constricted substantially transversely to the cylindrical axis of the rod.
The term “substantially free of tobacco” as used herein means that the aerosol generating substrate contains less than 30 wt.% of tobacco in dry weight basis.
The term “off note” as used herein refers to undesirable taste/notes emanates from the raw materials that are used.
The present invention is directed to products i.e. the devices and methods are configured to sufficiently heat by any suitable means thereof including electrical resistive heating, induction, radiation and the like to cause sufficient generation of an aerosol.
The present invention relates to aerosol delivery through a cereal fiber based reconstituted solid aerosol generating substrate.
The aerosol generating substrate of the present invention is made up of cereal fibers and the said substrate is substantially free from tobacco. The present invention resides in using the cereal fibers such as husk and forming the powder into substantially tobacco free pliable reconstituted sheet which can be pleated and folded in a defined way to make aerosol generating substrate.
Cereal husk-based aerosol generating substrate suitable for electrically heated not burn aerosol delivery system to deliver flavor, targeted actives and/or nicotine is not known in the prior art. Furthermore, the reconstituted solid aerosols as described in the present invention surprisingly does not require cellulose pulp to form the aerosol generating substrate and hence free from the characteristic note of cellulosic pulp. Cellulose pulp (raw content) is extracted from wood chips by digesting the wood chips in aqueous chemical solution under high pressure and temperature. This process removes lignin and other undesirable chemicals and leaves a white water insoluble fiber which can further be used to make paper. It has been used as sheet former due to its fiber network formation properties. Use of paper based cellulosic pulps is required to achieve the required mechanical strength of the dried sheet. However, it was experienced that the presence of cellulosic pulp in reconstituted tobacco leads to a distorted sensory which is coined as off note. Consumers associate this as cellulosic off note.
Since the non-tobacco reconstituted sheet of the present invention does not require addition of cellulose pulp, hence free from such characteristic note.
The present invention provides an aerosol generating substrate, which is substantially free of tobacco, comprising:
i. At least one cereal fiber(s);
ii. At least one aerosol former;
iii. At least one active;
iv. Optionally additives; and
v. Water.

In an embodiment, the said cereal fiber is in a form selected from husk, bran, straw, chaffs or combinations thereof.
In an embodiment, the cereal fibres used are rice and wheat husk, bran, straw, chaffs, which are the leftover of cereals. It is used to make substantially tobacco free pliable reconstituted sheet which can be pleated and folded in a defined way to make aerosol generating substrate.
In an embodiment, the cereal is selected from wheat, rice or combinations thereof.
Cereal husk such as wheat husk has gluten. Rice husk has substantial amount of cellulosic materials which support the formation of reconstituted sheet with required mechanical properties.
In an embodiment, the aerosol former is selected from glycerin, propylene glycol, triethylene glycol, tetraethylene glycol, carboxylic acid aliphatic esters such as methyl stearate, dimethyl dodecanedioate, and dimethyl tetradecanedioate or combinations thereof.
In an embodiment, the additives are selected from binder, flavorings or combinations thereof.
In an embodiment, the active is selected from nicotine, nicotine salts, nicotine flavor extracts, other botanical extracts and/or oils and a combination thereof.
In an embodiment, the active is nicotine which is tobacco derived or synthetic.
In addition to the above, a flavor additive that adds a flavor as required is also preferably used. Examples of the flavor additive include menthol, bran, cocoa, coffee, tea extract and the like.
In an embodiment, the binders are selected from carboxymethyl cellulose, guar gum or combinations thereof.
In an embodiment, the cereal fiber is present in an amount ranging from 65%, to 80% wt.%, the aerosol former is present in an amount ranging from 15 % to 30 wt.%, active is present in an amount ranging from 0.1 to 8 wt.% and the additives (Flavour , Binder) are present in an amount ranging from 0 to 15% wt.%. Preferable range: cereal fiber: 75%, Aerosol Former: 15 %, Active: 1%. Flavour: 2% & Binder 3 %.
A processing example of the present invention, where slurry casting has been used as a process for manufacturing aerosol generating sheet, the viscosity of the homogenous slurry has been optimized in the range of 35000-45000 cps. This viscosity is required to cast the slurry on moving conveyor belt as thin sheet. In an embodiment, the ratio of the total solid content of cereal fibers, aerosol former, active and optional additives to water ranges from 1:2.5 to 1:3.5. However, additional water can be mixed to maintain the required viscosity of the slurry.
In an embodiment, the substrate is in the form of a reconstituted sheet gathered to form the substrate.
The present invention also provides a method for preparing an aerosol generating substrate which is substantially-free from tobacco, comprising the steps of:
a. Grinding the cereal fiber and optionally, tobacco;
b. Addition of aerosol former, active and additives to the cereal fiber of step (a) to form a homogenous slurry; and
c. Casting and dehydrating the homogenous slurry of step (b) to obtain the aerosol generating substrate which is substantially-free from tobacco.

The present invention also provides an aerosol-generating article comprising a rod of the aerosol-generating substrate, substantially free from tobacco according to present invention.
Advantages of present invention:
Use of substantially, non- tobacco substrates such as cereal husks, bran, chaffs, straws help in avoiding the use of tobacco for making aerosol generating substrate. Besides regulating the active delivery to the consumers. These are materials are used to make substantially tobacco free pliable reconstituted sheet which can be pleated and folded in a defined way to make aerosol generating substrate.

EXAMPLES
The following examples are meant to illustrate the present invention. The examples are presented to exemplify the invention and are not to be considered as limiting the scope of the invention. Also, features described with respect to one example may be applied to other examples, or combined with, or interchanged with, the features of other examples without departing from the scope of the present invention.

EXAMPLE 1
Composition of the aerosol generating substrate according to present invention
Rice bran powder – 76 Kg
Actives – 1 Kg
Carboxymethyl cellulose – 1 Kg
Glycerin -20 Kg
Flavour ingredients – 2 Kg
Water – 300 Kg
Total weight – 400 kg
Viscosity: 35000 cps-45000 cps
Casting on belt: Okay
The process of making the aforesaid substrate of pliable reconstituted sheet with rice bran comprises the following steps:
o Grinding and sieving dry rice bran in not more than 100-micron particle size.
o Dry blending the water soluble binder such as carboxymethyl cellulose.
o Formation of aqueous solution of the dry blend along with aerosol formers, active(s) and flavorings agents. Solid: Water = 1:3.
o Maintaining viscosity in the range of 35000-45000 cps.
o Casting the homogeneous slurry over a moving conveyor belt with a thickness of around 200 microns.
o Drying the casted slurry to a moisture level of not more than 13 % and thickness in the range of 150 microns.
o Wounding the dried pliable sheet over a core and store it for further processing.

EXAMPLE 2:
Comparative example/Non-working example
1] Non-working example 1:
Rice bran powder – 76 Kg
Actives – 1Kg
Carboxymethyl cellulose – 1 Kg
Glycerin -20 Kg
Flavour ingredients – 2 Kg
Water – 200 Kg
Total weight – 300 kg
Viscosity: 85000 cps-105000 cps
Casting on belt: Not casting on belt
From the aforesaid, it is observed that a non-tobacco substrate formulation comprising solids to water ratio of 1:2 does not achieve the desired viscosity and thereby cannot be casted on conveyor belt for forming pliable reconstituted sheets.
2] Non-working example 2:
Rice bran powder – 76 Kg
Actives – 1 Kg
Carboxymethyl cellulose – 1 Kg
Glycerin -20 Kg
Flavour ingredients – 2 Kg
Water – 400 Kg
Total weight – 500 kg
Viscosity: 15000 cps-22000 cps
Casting on belt: The casted mixture is not able to hold the structure hence levelling off. Does not turn into sheet.

From the aforesaid, it is observed that a non-tobacco substrate formulation comprising solids to water ratio of 1:4 does not achieve the desired viscosity and thereby cannot be formed into pliable reconstituted sheets.

EXAMPLE 3
A] Data of the sensory evaluation (e.g. flavor, aroma).
Sensory Parameters Tobacco Based aerosol generating substrate (comparative example) Wheat/Rice Bran based aerosol generating substrate (present invention)
Mouthful 3-3.5 on a scale of 5 3-3.5 on a scale of 5
Irritation 2 1-1.5
Taste and Flavour Quality 3.5 4
Overall Likeability 3.5 3.5-4
Table 1

From the aforesaid Table 1, it is observed that that the cereal based aerosol generating substrate of the present invention demonstrates lower irritation while having a higher taste/flavour quality and comparable overall likeability as that of the conventional tobacco based aerosol generating substrate.

B] Comparative results over non-tobacco substrates having binders and cellulose pulp.
Sensory Parameters With Binder and pulp (comparative example) With Binder & Without Pulp (present invention)
Mouthful 3-3.5 on a scale of 5 3-3.5 on a scale of 5
Irritation 1.5 1
Taste and Flavour Quality 3.5 4
Overall Likeability 3.5 4
Table 2

The specific composition of the non-tobacco substrate with binder + pulp used as comparative example: Cereal fiber: 75 %, Active: 0.5 %, Additives (binder +pulp): 4.5 % and Glycerine: 20 %.
From the aforesaid Table 2, it is observed that that the cereal based aerosol generating substrate of the present invention demonstrates lower irritation while having a higher taste/flavour quality and overall likeability as that of the non-tobacco substrates having cellulosic pulp.

C] Mechanical strength evaluation:
The mechanical strength of the sheet is the force required to break the sheet while pulling in the machine direction (MD). Universal Testing Machine (UTM) has been used to check the strength to break the sheet having dimension of 50mm X 50 mm at a constant force of 25 N/meter.
It was observed that a Tobacco Recon Sheet (comparative example) with 3% Binder and 5 % pulp has Mechanical Strength: 300 – 500 N/M.
Wheat/Rice Bran based reconstituted sheet according to present invention with 3% Binder with 0% pulp has Mechanical strength: 300 – 600 N/M.
Thus, it can be observed that the tobacco free substrate of present invention has an equivalent or higher mechanical strength as compared to tobacco recon sheets.
The substantially tobacco free substrate of the present invention can deliver Nicotine or other actives and flavors. Various applications include electrically heated nicotine delivery system, electrically heated targeted active delivery system and the like.
It is to be understood that the present invention is susceptible to modifications, changes and adaptations by those skilled in the art. Such modifications, changes, adaptations are intended to be within the scope of the present invention.
, Claims:
1. An aerosol generating substrate, which is substantially-free from tobacco comprising:
i. At least one cereal fiber ranging from 65 wt% to 80 wt%;
ii. At least an aerosol former from 15 wt% to 30 wt%;
iii. At least one active ranging from 0.1 wt% to 8 wt%;
iv. Additives ranging from 0 to 5 wt.%; and
v. Water.

2. The aerosol generating substrate as claimed in claim 1, wherein the cereal is selected from wheat, rice or a combination thereof.

3. The aerosol generating substrate as claimed in claim 1, wherein the cereal fiber is in a form selected from husk, bran, straw, chaffs or a combination thereof.

4. The aerosol generating substrate as claimed in claim 1, wherein the aerosol former is selected from glycerin, propylene glycol, triethylene glycol, tetraethylene glycol, carboxylic acid aliphatic esters such as methyl stearate, dimethyl dodecanedioate, and dimethyl tetradecanedioate or a combination thereof.

5. The aerosol generating substrate as claimed in claim 1, wherein the additive is a flavouring agent selected from menthol, bran, cocoa, coffee, tea extract and the like.

6. The aerosol generating substrate as claimed in claim 1, wherein the additive is a binding agent selected from carboxymethyl cellulose, guar gum, and the like.

7. The aerosol generating substrate as claimed in claim 1, wherein the said active is selected from nicotine, nicotine salts, botanical extracts and/or oils and a combination thereof.

8. The aerosol generating substrate as claimed in claim 7, wherein said active is nicotine which is tobacco derived or synthetic.

9. The aerosol generating substrate as claimed in claim 1, wherein the ratio of the total solid content of cereal fibers, aerosol former, active and additives to water is 1:2.5 to 1:3.5.

10. The aerosol generating substrate as claimed in any one of the preceding claims, wherein the substrate is in form of a continuous pliable reconstituted sheet.

11. The aerosol generating substrate as claimed in claim 10, wherein the said aerosol generating substrate has a mechanical strength from 300 – 600 N/M.

12. A method for preparing an aerosol generating substrate which is substantially free from tobacco comprising the steps of:
a. Grinding the cereal fiber;
b. Addition of aerosol former, active and other additives to the cereal fiber of step (a) to form a homogenous slurry to maintain a solids and water ratio of 1:2.5 to 1:3.5 and a viscosity of 35000-45000 cps; and
c. Casting and dehydrating the homogenous slurry of step (b) over a moving conveyor belt to obtain the aerosol generating substrate, substantially free from tobacco.

13. The method as claimed in claim 12, wherein the particle size of cereal fiber is less than 100-micron.

14. The method as claimed in claim 12, wherein the said substrate has a moisture level of not more than 13 % and thickness in the range of 150 microns.

15. An aerosol-generating article comprising a rod of aerosol-generating substrate as claimed in any one of the claims 1 to 11.