FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL/COMPLETE SPECIFICATION
{See section 10 and rule 13)
1. TITLE OF THE INVENTION
A method for mitigating/masking the bitter aftertaste of Stevia extract using herbal adjuvants

A METHOD FOR MITIGATING/MASKING THE BITTER AFTERTASTE OF STEVIA
EXTRACT USING HERBAL ADJUVANTS FIELD OF INVENTION
The present invention relates to the methods of mitigating/masking the bitterness of Stevia extract to enhance its acceptance among the consumers. The invention also discloses the application of natural adjuvant to mitigate the bitterness of Stevia extract. BACKGROUND OF THE INVENTION AND PRIOR ART
Stevia rebaudiana Bert. (Family- Asteraceae), a natural sweetener with low glycemic index and calorie has recently found widespread use in the food and pharmaceutical industries. Shade dried leaves of Stevia are 10 to 15 times sweeter than sucrose. The worldwide demand for natural sweeteners is increasing because of consumer awareness about harmful effects of artificial sweeteners. Increased consumption of food products enriched with sugars and artificial sweeteners has resulted in the development of various chronic diseases like obesity and diabetes.. Stevia glycosides (200 times sweeter than sucrose) from Stevia offer a solution to prevent of complex diabetic problems and obesity in modern mankind.
The Stevia rebaudiana contains biomolecules mainly of labdanum diterpenes, triterpenes, stigma sterol, tannins, volatile oils and eight diterpenenic glycosides (stevioside, steviobioside, dulcoside and rebaudiosides A, B, C, D and E). Sweetness of stevia is due to the presence of glycosides mainly stevioside and rebaudioside A (the sum of both make up from 5 to 10% of drug). The most abundant substances are stevioside and rebaudioside A. Out of the stevia glycosides rebaudiosides A is more sweeter and the most stable and is less bitter than stevioside (Cramer and Ikan, 1986). A post digestive bitter taste is associated to presence of steviosides in high levels and causes certain rejection of Stevia by consumers. Commercial interest and its use by the food and beverage industry have put the species in a prominent position in the international agriculture scene, as described due to the social demand for healthy and natural foods. The extract of stevia is prepared by dynamic maceration, ultrasound and microwave extraction using hot water, ethanol, and methanol as well as other chemical solvents.
In human nutrition and food technology application, dried leaves are commonly used with the sweetness is about 10-15 times sweeter than sugar, but with the reduced calorific value of 2.7kcal/g (Kaubaa et al, 2015; Savita, et al 2010). Associated health hazards due to increased

sucrose consumption have led to encourage use of low calorie natural sweetners (Lemus et al, 2012). Stevia is used as a better substitute for sucrose to diabetes mellitus, obesity, high blood pressure, renal protective effect, and promotion of oral health (Abou-Arab et al, 2010). Aside from the sweet taste, Stevia is popular because of its nutritional and chemical composition that is characterized by a high content of amino acids, minerals, and photochemical, especially polyphenols that contributes to a significant antioxidant activity (Zlabur et al, 2015) as compared to the other sweetener (sucrose and artificial sweeteners). In addition, Stevia leaf has excellent sensory and functional properties than other sweeteners (Goyal et al, 2010 and Reis et al, 2017).
The major constraint in expansion and acceptability of stevia sweetener as substitute of sugar is its slightly bitter after taste. Reducing bitter aftertaste to stevia extract by chemical method will make the final produce less acceptable due to the chance of residual effect of applied chemical adjuvants. Use of physical method along with natural edible sources to mask the bitterness may be more useful and acceptable. This may prove to be new vista in commercialization of product through this technology.
US5286489A discloses drug-polymer matrix compositions comprising an active ingredient
having an amine or amido group and a pharmaceutically acceptable copolymer having a plurality
of carboxylic acid and ester groups wherein the matrix dissociates in a media having a pH of less
than 4, thereby releasing the active ingredient into the media.
•j US9596874B2 discloses A composition for masking the bitter taste of potassium chloride or
other potassium salt used in a consumable product as a substitute, in whole or in part, for
common table salt.
US9668505B2 discloses edible compositions, for example, edible films and gummi confectioneries, that mask the taste of bitter tasting foods and/or foods that contain proteins such as meats and vegetables like broccoli, cabbage, spinach, etc..
WO 2012/148432 Al discloses composition includes a film former or gelling agent, an effective amount of a protein masker, and an effective amount of a bitter masker. The composition may also include flavoring agents, sweetening agents, and sensates.

EP1267829A1 discloses the films include a water soluble film-forming polymer, such as pullulan, and a taste masked pharmaceutically active agent, such as dextromethorphan.
US20170136078A1 discloses an edible oral film strip dosage form containing an unpalatable basic active pharmaceutical ingredient and an ion exchange resin as a primary taste masking agent.
OBJECTS OF THE INVENTION
One objective of the present invention is to find out better natural adjuvant (s) for masking of bitterness of hot water extract of Stevia.
Another objective of the present invention is to develop complete method for masking the bitterness of Stevia extract using edible botanical modulator.
SUMMARY OF THE INVENTION
In one aspect present invention relates to find out better herbal adjuvant(s) for masking of bitterness of hot water extract of Stevia comprising the steps of:
(a) Collection of dry Stevia leaves,
(b) Extraction of leaf extract with hot water with herbal adjuvants such as sweet basil, lamongrass and desi mint leaves (first method) and mixing of adjuvants such as sweet basil, lamongrass and desi mint leaves in hot water extract of stevia (second method),
(c) The organoleptic evolution of freshly prepared stevia extract using two methods of extraction using herbal adjuvants as given in step b,
In another aspect the invention relates to development of complete method to mask/reduce the bitterness of Stevia extract using herbal edible modulators comprising the steps of:
(a) Collection of dry Stevia leaves,
(b) Preparation of extract using two methods of hot water extraction of stevia using adjuvants as sweet basil, lemongrass and desi mint leaves

(c) The organoleptic evolution of freshly prepared stevia extract, based on the various sensory attributes like colour and appearance, flavor, taste and overall acceptability,
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings.
Fig. 1 First method of Stevia extract preparation
Fig. 2 Second method of Stevia extract preparation.
DETAILED DESCRIPTION OF THE PRESENT 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 of ordinary skill 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 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.
"Extract" is a preparation containing the active ingredient of a substance in concentrated form. "Adjuvant" is a pharmacological or immunological agent that modifies the effect of other agents.

"Stevia rebaudiana" is a plant species in the genus Stevia of the sunflower family (Asteraceae).
It is commonly known as candyleaf, sweetleaf or sugarleaf.
"Organoleptic" is acting on, or involving the use of, the sense organs. Organoleptic properties
are the aspects of food, water or other substances that create an individual experience via the
senses—including taste, sight, smell etc.
"Bitterness" is sharpness of taste; lack of sweetness or having a harsh, disagreeably acrid taste.
The challenge with removing the bitterness in stevia is that the steviol glycoside is comprised of
both sweetness and bitterness. By blocking/removing the glycoside you lose the bitterness but
you also lose the sweetness. The inventors of present application have developed a method to
mask the bitterness of Stevia.
Collection of Stevia plant samples:
Dry leaf samples were collected. from Herbal Garden, Department of Plant Physiology, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Madhya Pradesh (India). Methods of extraction of Stevia leaf extracts with herbal adjuvants
A. First method: - In this method shade dried Stevia leaves sample (10 gm) along with
fresh leaves of sweet basil, lamon grass and mint as adjuvants (2.5 gm each) was
boiled for 20 minutes in 50 ml of tap water. Extract was decanted and boiled till it
remained to 30 ml. This extract was used for organoleptic test. Extract obtained using
this method was not found appropriate in overall acceptability due to non masking of
bitter after taste although colour, flavour and sweetness was good.
B. Second method: - In this method shade dried Stevia leaves sample (10 gm) boil in
beaker mixed with 50 ml tap water for 20 minutes. Decant the extract and boiled till
extract remained to 30 ml and mix fresh leaves of sweet basil, lamon grass and mint
as adjuvant to hot liquid extract (2.5 gm each) and sealed with aluminium foil. Put
this for 24 hours. After that the extract was decanted again. This extract was used for
organoleptic test and found appropriate in all parameters of organoleptic test along
with significant masking of bitter after taste in hot water extract of Stevia leaves.
Organoleptic evalution
The organoleptic evolution of freshly prepared stevia extract was done by the panel of 10 judges
to assess the acceptability of the product based on the various sensory attributes like colour nad

a.
appearance, flavor, taste and overall acceptability. The evalution was done on a nino point
hedonic scale as given Amerine et al (1965).
Like extremely : 9
Like very much : 8
Like moderately : 7
Like slightly : 6
Neither likes nor dislike : 5
Dislike slightly : 4
Dislike moderately : 3
Dislike very much : 2
Dislike extremely : 1
References
Abau-Arab AE, Abau-Arab AA and Abu Salim MF.2010. Physico chemical assessment of
natural sweeteners stevioside produced from Stevia rebaudiana Bertoni plant. African
Journal of Food Science 4: 269-281. Crammer B and Ikan R. 1986. Sweet glycoside from the. stevia plant. Chemistry in Britain
22(10): 915-917. Goyal SK, Goyal RK and Samsher 2010. Stevia (Stevia Rebaudiana) a bio-sweetner.
International. Journal of Food Sciences and Nutrition, 61(1): 1-10. Kaubaa M, Roselolo SE, Sic Zlabur J, Jambrak RA, Brncis M, Grimi N and Barba FJ. 2015.
Current and new insights in the sustainable and green recovery of nutritionally valuable
compounds from stevia rebaudiana Bertoni. Journal of Agricultural and Food Chemistry, 63
(31): 6835-6846 Lemus MR, Vega GA, Zura BL and Ah-Hen K. 2012. Stevia rebaudiana Bertoni source of a
high, potenty natural sweetner: A comprehensive review on the biochemical, nutritional and
functional aspects. Food Chemistry, 132 (3): 1121-1132. Reis F, Alcaire F, Deliza R and Ares G. 2017. The role of information on consumer sensory
hedonic and wellbeing perception of sugar-reduced products: Case study with'orange juice
food. Quality and Prefernce, 111: 579-589. Savita SM, Sheela K, Sunanda S, Shankar AG and Ramakrishnan P. 2010. Stevia rebaudiana -
A functional component for food industry. Journal of Human Ecology, 15(4): 261-264. Zlabur JS, Voca S, Cevi N, Jezek D and Brncic M. 2013. Stevia rebaudiana Bertoni nutritional
and biochemical properties of natural sweetener. Journal of Agriculturae Conspectus
Scientificus, 78 (1): 25-30.
CLAIMS
I claim:
1. A method of masking/reducing the bitterness of Stevia comprising the steps of:
a. Collection of dry Stevia leaves,
b. Preparation of hot water extract of stevia leaves,
c. Addition of sweet basil, mint and lemon grass leaves in the hot extract and cover
with aluminium foil and keep it for 24 hours,
d. Decant the extract in separate flask using filter paper,
e. The organoleptic evaluation of freshly prepared stevia extract, based on the
various sensory attributes like colour and appearance, flavor, taste and overall
acceptability.
2. The method as claimed in claim 1 wherein an adjuvant sweet basil, which improves sensory properties of Stevia extract with masking bitter aftertaste.
3. The method as claimed in claim 1 wherein an adjuvant mint leaves, which improves sensory properties of Stevia extract with masking bitter aftertaste.
4. The method as claimed in claim 1 wherein an adjuvant lemon grass which improves sensory properties of Stevia extract with masking bitter aftertaste.