WO2009031160A1

WO2009031160A1 - An improved process for the preparation of natural vanilla extract

Info

Publication number: WO2009031160A1
Application number: PCT/IN2008/000529
Authority: WO
Inventors: Satyagalam Ranganatha Deshikacharya Sampathu; Madeneni Madhava Naidu; Bashyam Raghavan; Munna Singh Thakur; Sujit Pokka Vayalil Kumar; Vishweshwaraya Prakash
Original assignee: Council Of Scientific & Industrial Research
Priority date: 2007-09-07
Filing date: 2008-08-25
Publication date: 2009-03-12

Abstract

Fresh green vanilla beans of a recent harvest, or partially cured vanilla beans or preserved green vanilla beans are used as the starting material. A preparation containing natural tea enzyme is made from fresh tea leaves. Fresh/cured/preserved vanilla beans, after proper size reduction, are mixed in a suitable proportion with the tea enzyme preparation and incubated to facilitate action of natural enzymes on vanilla flavour precursors present in the beans. The fermented vanilla & tea enzyme mix is treated with ethanol to inactivate enzymes and to extract the vanilla flavour constituents into ethanol. This is followed by separation of solid phase from liquid phase and clarification, to obtain vanilla extract having characteristic flavour, appearance and acceptable vanillin content.

Description

"AN IMPROVED PROCESS FOR THE PREPARATION OF NATURAL VANILLA EXTRACT"

Field of the Invention The present invention relates to an improved process for the preparation of natural vanilla extract from fresh green beans.

Background of the Invention and Description of prior Art

Vanilla planifolia Andr. is herbaceous, perennial vine a tropical orchid. This spice crop is grown for its pleasant aromatic essence "Vanillin". Annual world production is estimated at around 3000-4000 MT. In India vanilla crop is getting established as an important spice crop (Sreekrishna Bhat and Sudharshan 2002). The genus vanilla belongs to the monocotyledonous family Orchidaceae, and perhaps is the only orchid crop, which is of economic importance as a spice, the others being valued as ornamentals. Over 100 species of vanilla have been described in scientific literature, but only three if these are considered important for commerce and cultivation. There are Vanilla fragrans Salish Ames also known as Vanilla planifolia Andrews b) Vanilla pompna Shiede and c) Vanilla tahitensis J.W Moore, of these, Vanilla planifolia is the most valued fruits flavor qualities and is therefore widely cultivated and used (Persleglove 1981). Vanilla pompna and Vanilla tahitensis yield vanilla beans of poorer quality. Green vanilla pods are almost odourless and the characteristic flavour of vanilla develops only when the mature beans are subjected to a controlled curing and conditioning process.

For Vanilla producing countries, it is mainly an export oriented flavouring material and the international market is very competitive and quality conscious for vanilla beans and vanilla based products. Hence, it will be important for the growers/processors to adopt suitable methods for processing of vanilla. In the vanilla/ flavour industry, vanilla extract is produced by extraction of cured vanilla pods with aqueous alcohol followed by desolventisation to get a brown/red coloured, viscous material called the vanilla extract /concentrate. The extract/concentrate contains the constituents responsible for flavour namely vanillin, and other soluble components such as fats, fiber and waxes. Vanillin/ vanilla extract is useful as a flavourant in foods and confectionary items. The industry aims at producing the pure natural vanillin/vanilla extract with a high flavor value, but the quality gets restricted due to the natural composition of the vanilla with respect to flavour.

The first critical phase is vanilla process is known as curing. A number of procedures have been evolved for curing of vanilla but they are all characterized by four phases whereby the green mature beans are transferred into a commercially desirable product. These phases are called killing, sweating, drying and conditioning. Killing or wilting brings about physiological death of the living tissues by respiratory function of the disrupting the cells. The cell-disruption can be carried out by subjecting the fresh beans to any one of the treatments such as hot water scalding, sun and oven wilting, scarification treatment with ethylene gas or freezing. Sweating helps the beans to develop their characteristic colour, aroma and flavouring properties. During the drying step the moisture is reduced and beneficial chemical changes take place. Due to conditioning stage, the beans are stored in closed boxes and this rests for several months. Various chemical and biochemical reactions take place in this step, producing various volatile aroma constituents enhancing the overall flavour quality of the cured beans (Purseglove 1981 , Randire 1984).

Reference may be made to a Japanese patent (JP8308528) which relates to the preparation of vanilla extract from cured beans using water and /or a water- soluble organic solvent in the presence of an alkali or alkali salt. Reference may be made to a Japanese patent (JP8168355) which recites the preparation of vanilla extract from cured beans employing water and /or aqueous organic solvent using the irradiation of ultrasonic waves. Another patent JP2002038188 relates to the preparation of vanilla extract from cured vanilla beans employing cocoa butter to enhance the vanilla flavour.

Reference may be made to the patents JP9111285 and KR255037 that relate to preparation of vanilla perfume by treating vanilla pods with specific microorganisms followed by extraction with an organic solvent. Reference may be made to a series of patents involving the use of enzymes for vanilla extraction. GB812443 relates to green vanilla beans being extracted in substantial absence of oxygen and the extract cured. An enzyme system can be added during or prior to the curing and concentration of the extract that preferably precedes curing; W09325088 deals with bringing vanilla beans in contact with enzymes of the pectinase, cellulase and /or hemicellulase type and making a beta-glucosidase enzyme react and extracting natural vanilla flavour thus obtained.

GR3022203T relates to a process for the production of natural vanilla extract, consisting of processing crushed green vanilla pods by means of an enzymatic system capable of destroying plant cell membrane systems and hydrolysing glycoside precursors of volatile compounds. JP2001181671 relates to preparing vanilla extract by treating cured vanilla beans or its extract with at least one enzyme selected from protease, astringency / bitterness splitting enzyme and hesperidin splitting enzyme. WO2004091316 relates to a process for the preparation of a vanilla extract, the process consisting of subjecting green vanilla beans to accelerated browning followed by extractive / enzymatic treatment.

US4956192 relates to the preparation of natural vanilla flavour comprising freezing green vanilla beans at 5 degree and -30 degree, thawing and then extracting the flavour constituents from the beans. US5705205 relates to enzymatic treatment of a hydrated slurry of ground dehydrated green vanilla pods, addition of enzyme consisting of 10-1000 units of beta-glucose activity per gram of green vanilla pods followed by incubation and phase separation to obtain vanilla extract.

Reference may be made to a bioconversion process for the production of vanillin (US5279950) wherein vanillin is produced through biOconversion of vanilla precursor with a tissue culture of undifferentiated callus cells derived from a vanilla plant and / or enzymes obtained therefrom in the presence of a water soluble sulfhydryl compound and an assimilable carbon source. Production of novel vanilla extract using Co2 of a supercritical state (JP4214799) wherein, preparation of vanilla extract from cured beans initially by supercritical carbon dioxide and subsequently with a polar organic solvent is reported.

Preparation of enhanced vanilla flavour has also been reported. JP58056654 relates to the preparation of vanilla flavour with enhanced fragrance by extracting a mixture of pulverized vanilla beans or dried material with spice vegetable material of allspice, caraway, cardamom, cassia or cinnamon with a water- miscible organic solvent.

Relevant earlier patents (as indicated above) mention use of enzymes such as protease, astriningency / bitterness splitting enzyme and hesperdins splitting enzyme and β-glucosidase for the preparation of vanilla extract. For any vanilla extract chemical flavour quality as assayed by gas chromatographic method and also organoliptic quality for sensory acceptance are considered two important quality attributes. However, this aspect does not appear to be adequately addressed in the above patents. It is desirable to produce a vanilla extract similar or better in quality as compared to the commercially manufactured extracts, wherein cured vanilla beans are used as the starting material.

However, keeping in view the drawbacks of the reported prior art the present invention involves a novel approach wherein a natural bioactive preparation made from green tea leaves which has enzymatic activity capable of action on phenolic precursors of green vanilla beans and forming characteristic vanilla flavour compounds, is made use of. The flavour quality of the extracts so prepared has been assessed chemically and organically as seen to be highly acceptable in tune with to conventional cured vanilla extracts. In this application a method is provided for the preparation of the vanilla extract from green vanilla pods by using enzymes obtained from fresh tea leaves (one bud two leaves). Objects of the Invention The main object of the present invention is thus to provide an improved process for the preparation of vanilla extract from green vanilla beans which obviates the drawbacks of the prior art.

Another object is to provide a process wherein the vanilla extract is prepared without using any chemicals / commercial enzymes. Yet another object is to enhance the extractability of vanilla constituents with acceptable flavour by a combination of fresh vanilla pulp with an enzyme preparation derived from fresh tea leaves in a crude or purified form.

Summary of the Invention

Accordingly, the present invention provides an improved process for the preparation of natural vanilla extract, wherein the process comprises the steps of: a) grinding partially cured fresh vanilla pods/partially cured stored vanilla beans in water [in the ratio of 1 :0.25 to 1 :1 w/v] to obtain a paste; b) simultaneously grinding fresh tea leaves separately with ice-cold ethyl alcohol [in the ration of 1 :2 to 1 : 4 w/v] to obtain a slurry; c) separating solid phase from liquid phase of the slurry as obtained in step (b) followed by repeated washings of the solid phase with ethanol to remove tea constituents such as caffeine, polyphenols, and chlorophyll; d) drying the solid phase as obtained from step (c) at a temperature below

30 degree Celsius to obtain a powder containing natural tea enzymes; e) mixing the powder obtained in step (d) with the paste as obtained in step (a) in a ratio of 5 : 85 to 20 : 80 w/w to obtain a slurry; f) incubating the slurry obtained in step (e) at a temperature in the range of 40 to 50 degree Celsius for about 2 - 48 h to get maximum yield of vanillin; g) adding absolute alcohol to the slurry obtained in step (f) in a ratio of

1:0.5 to 1 :2 w/v and providing a contact time of 1-6 hr to inactivate the enzyme and to extract the constituents; h) separating solid phase from liquid phase of the slurry as obtained in step (g) followed by clarification to obtain natural vanilla extract with characteristic aroma , brown color and vanillin content not less than

0.2% w/v; i) optionally subjecting the vanilla extract as obtained in step (h) to partial desolventization at reduced pressure followed by clarification by filtration to obtain vanilla extract containing 0.2 - 0.4 % w/v vanillin and having desirable characteristic flavor and brown color.

In an embodiment of the invention, partially cured vanilla beans are prepared by controlled heat treatment and conditioning of green vanilla beans of a recent harvest which is used for extraction.

In another embodiment of the invention, partially cured vanilla beans are prepared by controlled heat treatment and conditioning of stored mature green vanilla beans. In still another embodiment of the invention, mature green vanilla beans are preserved by storing them in a cold room for up to 6 months at a temperature of 0- 8 degree Celsius.

In yet another embodiment of the invention, the mature green beans are preserved by storing in a deep freezer for up to 12 months, at a temperature of - 40 to -80 degree Celsius.

In a further embodiment of the invention, partial curing of fresh or stored green vanilla beans is effected by holding the green beans in a hot air drier at a temperature of 40-70 degree Celsius for 1-3 hrs every day for a period of 5-15 days and holding the warm, vanilla beans in an insulated chamber to preserve the heat, immediately after the hot air exposure and till the next hot air exposure. In another embodiment of the invention, fresh or stored green vanilla beans subjected to partial curing by known art involving components of holding the beans in hot water/steam, repeated exposure to hot sun, and repeated sweating of the warm beans in wooden box, is mixed, after size reduction, with the enzyme preparation made from green tea leaves as described under claim 1 , to be followed by incubation and extraction as described.

In yet another embodiment of the invention, natural tea enzymes has an activity of 7000-28,000 units of PPO per gram , 150-300 units of galactosidase activity per gram, 1000-2000 units phenylalanine ammonia lyase activity per gram and 700- 1500 units glycosidase activity per gram when as determined by standard methods of enzyme assay.

In yet another embodiment of the invention 10 gms of the powder containing the tea enzymes is mixed with an extraction buffer prepared with potassium phosphate 0.05M, pH 6.8; containing 0.35M KcI, 0.25% Triton X-100 and 0.01 mM

PMSF and transferred to a mortar. To this 20 g of acid washed sand, 10 g of PVP and 100 ml of buffer were added and ground. Homogenate was filtered through a muslin cloth to get the first extract containing tea enzymes. Volume of first extract was 60 ml. Similarly second and third extract were prepared and the three extracts pooled (230 ml), were centrifuged at 10, 000 rpm, 20 min at 4⁰C. Aliquots of the clear enzyme extract are used for activity evaluation.

In still another embodiment of the invention, the enzyme containing powdery preparation from tea leaves is treated with commercial cellulase enzyme with an activity of 5000 to 7500 S Units, at a concentration of 0.2 -1.0% by weight of the tea enzyme powder with the moisture level maintained at 40-70% by addition of water, maintaining the pH at 4-5, and incubated at 35-40 degree Celsius for 1 to 3 hours to facilitate release of the tea enzymes for action on vanilla bean

In another embodiment of the invention, the enzyme powder was dispersed in water and treated with commercial cellulase by holding at 40-50 degree Celsius for 1-3 hrs to facilitate release of enzymes adhering to the matrix, In yet another embodiment of the invention, the natural enzymes containing preparation from green tea leaves is made by using the known art of employing acetone as solvent but subsequently rinsing with ethanol to remove the adsorbed acetone, followed by gentle drying and grinding to obtain a powdery enzyme containing preparation, which can be used as a source of enzymes.

In yet another embodiment of the invention, as an optional step, the vanilla extract from step 1(i) is subjected to partial desolventization at reduced pressure and clarified by filtration to obtain vanilla extract containing 0.2 - 0.4 % vanillin and having desirable characteristic flavour and brown color.

Detailed Description of the Invention

Fresh green vanilla pods were collected from the region of Koppa, Chikmagalur District, Karnataka, India and were procured from Mr.Darryl Colaco, Kalsapur Estate, Local producer, before the curing process was begun. The vanilla beans were first subjected to a partial curing process. Mature green vanilla beans of a recent harvest or green beans stored in a cold room or in a deep freezer can be used for partial curing, wherein beans were subjected to controlled heat treatment and conditioning for up to 15 days. The beans were held in a hot air dryer at a temperature of 40-70 degree Celsius for short spells of 1-3 hrs over 3 - 15 days. For rest of the period in between the thermal treatments, the beans were stored in an insulated chamber. Freshly harvested tea leaves (one bud two leaves) were subjected to thorough pre-cleaning by visual inspection to sort out and remove any extraneous matter and washing with potable water. The cleaned tea leaves were macerated with ice-cold ethanol to obtain fine slurry of the leaves in ethanol. The slurry was processed to separate the solid phase from the liquid phase. The solid phase was rinsed well with ethanol to remove tea constituents such as caffeine, polyphenols and chlorophyll and dried gently to remove the adsorbed solvent and obtain a free-flowing powder preparation containing enzymes from green tea leaves, especially polyphenol oxidase and β-primeeraridase. This powder retained 80% of its enzyme activity after 3 months storage in a refrigerator. Partially cured vanilla beans were macerated to a paste or cut into bits and mixed with the tea enzyme preparation made as described above from fresh tea leaves. The mixed mass was incubated at 35-50 degree Celsius for a period of 2 - 48 hrs, wherein enzymes helped the development of characteristic vanilla flavour constituents by acting upon the vanilla flavour precursors. The fermented mass was treated with ethanol to inactivate the enzymes and extract vanilla flavour. The solid phase was separated from the liquid phase to obtain natural vanilla extract. In order to enhance the vanillin content, vanilla extract can be desolventized partially under reduced pressure and clarified to obtain vanilla extract of characteristic brown colour, aroma and having vanillin strength to meet regulatory requirements.

The enzyme containing powdery preparation from tea leaves is treated with commercial cellulase enzyme with an activity of 5000 to 7500 S Units, at a concentration of 0.2 -1.0% by weight of the tea enzyme powder with the moisture level maintained at 40-70% by addition of water, maintaining the pH at 4-5, and incubated at 35-40 degree Celsius for 1 to 3 hours to facilitate release of the tea enzymes for action on vanilla bean.

The natural tea enzymes has an activity of 7000-28,000 units of PPO per gram , 150-300 units of galactosidase activity per gram, 1000-2000 units phenylalanine ammonia lyase activity per gram and 700-1500 units glycosidase activity per gram when as determined by standard methods of enzyme assay.

The enzyme containing powdery preparation from tea leaves is optionally treated with commercial cellulase enzyme with an activity of 5000 to 7500 S Units, at a concentration of 0.2 -1.0% by weight of the tea enzyme powder with the moisture level maintained at 40-70% by addition of water, maintaining the pH at 4-5, and incubated at 35-40 degree celsius for 1 to 3 hours to facilitate release of the tea enzymes for action on vanilla bean.

Novelty

The partially cured mature green vanilla beans, after size reduction are treated with an enzyme preparation made from fresh tea leaves which facilitate better formation of the natural vanilla flavour constituents which is a novel inventive step. Vanilla extract of good flavour quality is obtained avoiding the prolonged traditional curing step.

The following examples are given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention.

Example 1

Fully mature green vanilla beans (10 kg) were procured from an orchard in a local growing area and 5 kg batch each of the beans were stored in a cold room (0 - 4 degree Celsius) for up to a period of 4 months, and in a deep freezer maintained at -40 degree Celsius for up to a period of 12 months.

Natural Enzyme powder preparation: Freshly harvested tea leaves (two leaves and a bud) processed within 48 hours of the harvest. Tea leaves were thoroughly cleaned with potable water. Tea leaves (50Og) were blended with ice-cold 80% ethanol (2 liters) using a blender to get a homogenous paste. This paste was charged into a Buckner funnel and repeatedly washed with ice-cold ethanol. The creamy whitish powder was dried below 30 degree Celsius and to obtain the tea enzyme powder (100g). The powder contains natural tea enzymes.

Example 2

Fresh tea leaves (two leaves and a bud) were collected and kept overnight for freezing. Frozen crispy tea leaves (100gms) were transferred to a blender, and chilled aqueous alcohol (300 ml) was added. This was ground to a pulp and transferred to a buckner funnel. The pulp was washed repeatedly (1.5L of 80% ethanol)) to remove caffeine, chlorophyll and other pigments present in the material. Finally it was washed with 100% ethanol (500 ml) to remove the moisture present in the material. The residue was dried at ambient conditions (27±5°C) to remove all the adsorbed solvent. A creamy white powder containing tea enzymes was obtained. Extraction buffer was prepared with potassium phosphate 0.05M, pH 6.8; containing 0.35M KCI, 0.25% Triton X- 100, and 0.01 mM PMSF. 10gms of enzyme powder was weighed and transferred to a mortar. To this 20 g of acid washed sand , 10 g of PVP and 100 ml of buffer were added and ground. Homogenate was filtered through a muslin cloth to get the first extract containing tea enzymes. Volume of first extract was 60 ml. Similarly second and third extract were prepared and the three extracts pooled (230ml), were centrifuged at 10,000 rpm, 20 min at 4°C. Aliquots of the clear enzyme extract were used for activity evaluation ad detailed below.

Enzyme assay

Polyphenol oxidase: A reaction mixture was prepared with 5OmM phosphate buffer of pH-6.8, which contains 1OmM catechin as substrate. An aliquot of enzyme extract was added and absorbance measured at 42OnM. Change in 1 unit of absorbance is one unit activity of PPO.

Glycosidase: In a total volume of 0.5ml, the reaction mixture contained

100mMol/l sodium acetate buffer, pH 4, 5 mM of sucrose as substrate, and an aliquot of the enzyme. Incubation was for 15 min at 32 ⁰C. The reaction was stopped by adding 2.0ml of 0.1 mol/L NaOH and the absorbance of released pNP was measured at 410 nm.

Galactosidase: Same assay method as used for glycosidase. Lactose was used as the specific substrate.

Phenylalanine ammonia lyase: Assay of the enzyme was done at 273nm with phenylalanine as substrate. One unit of activity is defined 1mM cinnamic acid formed/hr by 1g enzyme powder.

TableA: Enzyme profile of natural enzyme powder

Example 3

Vanilla beans in requisite quantity were procured from vanilla gardens. And beans were converted to a paste. An aqueous slurry pf the tea enzyme powder was made to which a commercial cellulase enzyme (5000 units/ml/min.) at 1% wt/volume on the basis of the tea enzyme powder was added and incubated at 45 degree Celsius for 2 hours and this was mixed with the vanilla bean paste followed by incubation at 45 degree Celsius with agitation for 48 hours. This was followed by alcohol addition and liquid phase separation to obtain vanilla extract. The results of examples 2 & 3 are presented in Table.1

Table.1 Effect of added tea enzyme preparation on vanillin recovery in extracts

Example 4

Vanilla beans in requisite quantity were withdrawn from cold storage and from frozen storage separately and subjected to partial curing by holding in a hot air drier at 50 degree Celsius for 2 hrs, daily for a period of 3 days. The beans were converted to a paste. Tea enzyme extract preparation from tea enzyme powder and having an activity of 4300 polyphenol oxidase units /ml/ min was added to the vanilla paste at 10% and 20% by weight of the paste and incubated at 45 degree celsius with agitation for 2 hours followed by alcohol addition and liquid phase separation and clarification to obtain vanilla extract. The results are presented in Table.2. Table 2 : Recovery of vanillin under different experimental conditions

Example 5

Vanilla beans in requisite quantity were withdrawn from cold storage and from frozen storage separately and subjected to partial curing by holding in a hot air drier at 50 degree Celsius for 2 h, daily for a period of 3 days. The beans were converted to a paste with added water and mixed with the tea enzyme powder (8% w/w on vanilla paste). The mixture was incubated at 45 degree Celsius with agitation for 48 h and then stirred gently (2 h) with equal volume of ethanol. The solid phase was separated from liquid phase and clarified to obtain vanilla extract. Advantages of this process are :

1. Green vanilla beans stored from 3 months to 1 year can be used for processing into extract as and when needed.

2. Down stream processing time for making the extract starting from partially cured beans is very low (2 to 3 days) compared to traditional extraction methods from cured beans, which takes many weeks.

3. Vanilla extract prepared with out using any chemicals / commercial enzymes.

Claims

We claim:

1. An improved process for the preparation of natural vanilla extract, wherein the process comprises the steps of: a) grinding partially cured fresh vanilla pods/partially cured stored vanilla beans in water [ in the ratio of 1:0.25 to 1:1 w/v] to obtain a paste; b) simultaneously grinding fresh tea leaves separately with ice-cold ethyl alcohol [in the ration of 1 :2 to 1 : 4 w/v] to obtain a slurry; c) separating solid phase from liquid phase of the slurry as obtained in step (b) followed by repeated washings of the solid phase with ethanol to remove tea constituents such as caffeine, polyphenols, and chlorophyll; d) drying the solid phase as obtained from step (c) at a temperature below

30 degree Celsius to obtain a powder containing natural tea enzymes; e) mixing the powder obtained in step (d) with the paste as obtained in step

(a) in a ratio of 5 : 85 to 20 : 80 w/w to obtain a slurry; f) incubating the slurry obtained in step (e) at a temperature in the range of

40 to 50 degree Celsius for about 12 - 48 h to get maximum yield of vanillin; g) adding absolute alcohol to the slurry obtained in step (f) in a ratio of

1 :0.5 to 1:2 w/v and providing a contact time of 1-6 hr to inactivate the enzyme and to extract the constituents; h) separating solid phase from liquid phase of the slurry as obtained in step

(g) followed by clarification to obtain natural vanilla extract with characteristic aroma , brown color and vanillin content not less than

0.2% w/v; i) optionally subjecting the vanilla extract as obtained in step (h) to partial desolventization at reduced pressure followed by clarification by filtration to obtain vanilla extract containing 0.2 - 0.4 % w/v vanillin and having desirable characteristic flavour and brown color.

2. A process according to claim 1 , wherein partially cured vanilla beans are prepared by controlled heat treatment and conditioning of green vanilla beans of a recent harvest/ stored mature green vanilla beans.

3. A process according to any preceding claims, wherein the mature green vanilla beans are preserved by storing them in a cold room for up to 6 months at a temperature of 0-8 degree Celsius or by storing in a deep freeze for up to 12 months at a temperature of -40 to -80 degree Celsius.

4. A process according to any preceding claims, wherein partial curing of fresh or stored green vanilla beans is effected by holding the green beans in a hot air drier at a temperature of 40-70 degree Celsius for 1-3 hrs every day for a period of 5-15 days and holding the warm, vanilla beans in an insulated chamber to preserve the heat, immediately after the hot air exposure and till the next hot air exposure.

5. A process according to any preceding claims, wherein the natural tea enzymes have an activity of 7000-28,000 units of PPO per gram, 150-300 units of galactosidase activity per gram, 1000-2000 units phenylalanine ammonia lyase activity per gram and 700-1500 units glycosidase activity per gram.

6. A process according to any preceding claims, wherein the enzyme preparation from tea leaves is optionally treated with commercial cellulase enzyme with an activity of 5000 to 7500 S Units, at a concentration of 0.2 -1.0% by weight of the tea enzyme powder with the moisture level maintained at 40-70% by addition of water, maintaining the pH at 4-5, and incubated at 35-40 degree Celsius for 1 to 3 hours to facilitate release of the tea enzymes for action on vanilla bean.