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(11) Patent Number: KE 423       
                       
(45) Date of grant:  10/02/2011       
   
(73) Owner:A 23F 3/00    Unilever PLC of Unilever House, Blackfriars, London EC4P 4BQ,United Kingdom   
   
(21) Application Number: KElP/ 2007/ 000569   

(72) Inventors: JONES, Timothy, Graham of Unilever R & D Col worth, Shambrook, Bedford Bedfordshire MK44 ILQ, United Kingdom and SHARMA,Navin, Kumar of Hindustan Lever Research Centre, Whitefield, P.O. , Bangalore, Kamataka 560 066, India.       

(22) Filing Date: 04/08/2005

(30) Priority data: 0419691.1  04/09/2004  GB   

(74) Agent/address for correspondence:Kaplan & Stratton Advocates,  P.O. Box 40111-00100, Nairobi       

(86) PCT data  PCTIEP05/008498 04/08/2005 W0/2006/027063 AI 16/03/2006

(54) Title: PROCESS FOR MAKING TEA

(57) Abstract: A process for manufacturing amino acid-rich tea or tea extract is provided. The process uses tea starting material comprising at least 50wt% of tea plant material harvested within 3 hours before and after sunrise and then processing the tea in a conventional tea process and packaging to provide a vendible tea product comprising at least 50wt% of tea plant material harvested within 3 hours before and after sunrise. The observation that tea has more amino acids near to sunrise gives rise to a tea which is naturally high in amino acids.

PROCESS  FOR  MAKING  TEA

The present invention relates to a process for making amino acid-rich tea or tea extracts.

5

BACKGROUND  AND  PRIOR  ART


Tea is generally prepared as green leaf tea or black leaf tea. The method of preparing such teas is well known to those skilled

10    in the art. Generally, to prepare black leaf tea, fresh green leaves of the plant Camellia sinensis are withered (subjected to mild drying), comminuted, fermented (in which process enzymes in the leaf tea use atmospheric oxygen to oxidise various substrates to produce brown-coloured products) and then fired (to dry the

15    tea leaves) . Green leaf tea is not exposed to the fermentation process. Partial fermentation may be used to produce intermediate-type teas known as "oolong" tea. Conventionally, a portion of the upper most part of the tea plant is harvested,

which usually  involves plucking  a  number  of  leaves  (normally  two

20    to up  to  seven)  together with  a  bud.

Today tea based beverages can be prepared by methods other than infusing leaves in hot water and served in ways other

than  poured  from  tea pots.    For  example  they  can  be  made  with

25    concentrates or powders that are mixed with hot water in vending machines or used to prepare ready to drink teas in cans and bottles. Consumers also demand more from tea such

as  accelerated  infusion,  more  colour,  more  aroma.


3 0 In particular the modem constnner is interested in naturally healthy beverages which form part of a modem healthy lifestyle. As a beverage, tea fits well with this attitude in view of its natural content of inter alia flavonoids, catechins and amino

acids. There is therefore a need in the art to provide a method for the concentration of these naturally occurring healthy ingredients whilst maintaining the healthy nature of tea without adding synthetic compounds.

5

The present inventors have surprisingly discovered that material of the tea plant camelia sinensis contains a higher concentration of amino acids when harvested in the early hours of the morning. It is believed that amino acids are generated through the night

10    and  are  used up  during the  day.


Thus, the present invention provides a process for manufacturing amino acid-rich tea or tea extract using tea starting material

comprising  at  least  sowt%  of  tea plant  material  harvested withL,

15    3 hours before and after sunrise and then processing the tea in a conventional tea process and packaging to provide a vendible tea product comprising at least SOwt% of tea plant material harvested within 3 hours before and after sunrise.



20    In a second aspect, the present invention provides a packaged tea product which comprises at least 50wt% of tea plant material harvested within 3 hours before and after sunrise.

DETAILED DESCRIPTION OF  T.HE  INVENTION

25

The process of the present invention comprises the steps of harvesting a tea source material at or near to sunrise and then processing and packaging the tea. The starting material and the resultant packaged product comprise at least SOwt% of tea plant

30    material harvested within 3 hours before and after sunrise where the tea is harvested.
 
The leaf tea is preferably processed in a convention black tea manufacturing process, comprising the steps of withering, maceration, fermentation, firing.


5 "Tea" for the purposes of the present invention means leaf material from Camellia sinensis var. sinensis, or Camellia sinensis var. assamica. "Tea" is also intended to include the product of blending two or more of any of these teas.

10    Early morning  tea


Tea is conventionally plucked gradually throughout the day and no particular preference is placed on tea plucked in the morning, afternoon or evening. Therefore, conventional processes use tea

15    which is a blend of tea plucked throughout the working day as a starting material. Sometimes tea plucked early in the morning is collected as a batch to be processed. In this case, although the starting material may be early harvested tea, the processed tea

is  blended with tea  harvested  later  in  the  day,  so  no  packaged

20    vendible product  based  on  early harvested tea  is  ever produced.


For the purposes of the present invention, at least 50wt% of the starting material and/or the packaged product is early harvested tea which is tea plant material harvested within 3 hours before

25    and after sunrise. In this way, the concentration of amino acids is naturally increased due to our observation that their concentration in the tea plant is higher near to sunrise.

Preferably the  starting material  and/or  the  packaged product  tea

30    comprises at least 60 wt%, more preferably at least 70 wt% of early harvested tea. The starting material and/or the packaged product may comprise as much as 80 wt% early harvested tea, as

much as 90 wt% early harvested tea or may even be 100 wt% early harvested tea.

Early  harvested  tea  is  tea  plant  material  harvested within  3

5    hours of sunrise at the locale of the tea plant. Preferably early harvested tea is tea plant material harvested within 2 hours of sunrise, or even within 1 and a half hours of sunrise, or even within 1 hour of sunrise.


10    Processing  the  tea material


In the process of the present invention, the early morning tea material is preferably processed as though it were normal leaf tea. In this way, the tea material is subjected to at least on

15    of the following black tea processing unit operations: withering, maceration, grinding, steaming, fermentation, firing and infusing. Thus the tea may be black, green, or oolong tea.

Preferably  the  tea material  is  subjected  to  withering,  a

20    maceration step followed by fermentation and firing to arrest fermentation. This is a conventional black tea process.

Once  produced,  the  tea  is  further  processed  to prepare  the  tea

for  sale  as  a  vendible  product.   The  vendible  product  remains  an

25    early harvested tea, even though this allows for the possibility of some dilution after or during processing provided the vendible product remains at least 50wt% of tea plant material harvested within 3 hours before and after sunrise.



3 0    Maceration

The leaf tea may be macerated. One can macerate tea in many ways but broadly speaking there are two main mechanised methods for doing this.


5    The first, called "orthodox manufacture", involves rolling withered tea leaves as part of a standardised procedure including fermenting and drying steps. So called "orthodox tea" is typically characterised by large leaf portions that are

aesthetically pleasing to many but  produce  lighter  liquors  due  to

10    less  extensive  fermentation.


The second method is the most popular of a number of non-orthodox methods that involves using a machine resembling a mangle that cuts, tears and curls tea leaves. The original machine was

15    invented by W. McKercher in 1930 and is commonly referred to a ere (cut-tear-curl) machine. The finely cut product is known generically as "CI'C tea" and is characterised by a fast infusion rate and strong colour.



20    Both orthodox and CTC machines are often used in conjunction with a Rotorvane machine that minces withered tea leaves . These

methods and their history and role in tea manufacture are described in "Tea: cultivation to consumption" edited by K. c.

Willson  and M.  N.  Clifford,  Chapman  & Hall,  1992.

25

Generally speaking consumer preference for either orthodox or CTC tea is a matter of national or regional culture. In some countries the visual appearance and texture of leaf tea are both important indicators of quality, larger leaf particles being

30    associated with higher quality. In Western markets tea is increasingly purchased in filter paper bags and the colour of the infused product is more important •

Fermentation


The next optional step is commonly called fermentation but that is a misnomer. "Fermentation" is commonly used in the context of

5    brewing alcohol to describe the action of exogenous enzymes. However in the tea world it is used to refer to the oxidative process that tea undergoes when certain endogenous enzymes and substrates are brought together by mechanical disruption of the cells by tearing or cutting the leaves. Tea and other plant

10    material can be oxidised by the action of exogenous enzymes such as oxidases, laccases and peroxidases so for present purposes the term "fermentation" will describe enzymic oxidation regardless of the source of the enzymes responsible The essential

fermentation  step  is  b   "eved to provide  the  desirable black  tea

15    colour  and  flavour  characteristics.


In order  to  terminate  fermentation,  the  tea  leaves  must  be

20    subjected to a high temperature for a short period of time. This stage is called 'firing' and is well-known in the art.

Infusion  of  tea

25
In a preferred process, the tea material is infused in water in order to extract the tea solids and amino acids. Preferably the tea material is at least fermented before infusion occurs.

30 Infusions of the tea material may be prepared using either a simple extraction process or an enzymatically assisted extraction process.

The tea material is preferably combined with water in an extractor at the desired temperature to obtain a tea infusion slurry containing extracted tea material and solid tea material. After infusion the solid tea material is separated

5    from the tea infusion for example by filtration and/or centrifugation.



Enzymatically  assisted  extraction,  if  used,  requires  the

addition  of  enzymes  to  the  extractor  in  the  form  of  an  enzyme

10    cocktail or the enzymes can be fed to the extractor individually. For example, an enzyme cocktail including selected cell wall lysis enzymes such as carbohydrases including cellulase and mascerase, for example, Viscozyme L~

obtainable  from  NOVO  Industri  A/S  Denmark  may  be  used.  The

15    tea slurry containing the enzymes is then hot extracted to complete the infusion process and the solid tea material is separated from the tea extract as above. The tea extract is then preferably pasteurised to deactivate the enzymes.



20    The resulting tea infusion is then optionally concentrated and then cooled and polished by centrifugation or other clarification methods such as filtration and the like. After polishing, the extract is then concentrated for example by

vacuum  concentration  or  by  falling  film  type  evaporation  and

25    dried for example by spray drying to give tea.powder for use in the present invention.

The resulting finished infusion may then be concentrated and/or dried to produce an amino-acid rich tea powder.

30
 

Packaging


Once the plucked tea has been processed, the tea is then packed in a form in which it may be sold. This may for example be large sacks for sale at an auction, or it may be a subsequent smaller packaging appropriate for sale to a consumer.

5

The final packaged tea may possibly contain tea which was added from a different source to the early morning tea starting material. However in this case, the packed tea product tmlSt still comprise at least 50wt% of tea plant material harvested

10    within  3 hours  before and after  sunrise.


Preferably the packaging is marked with an indication that the tea product is plucked early in the morning. Additionally, the

packaging  is  preferably marked with  an  indication  that  the  tea

15    product is high in amino acids, preferably marked as naturally high in amino acids. Preferably, the packaging is marked with an indication that the tea product is high in theanine, preferably marked as being naturally high in theanine.



2 0    EXAMPirES


Tea was plucked as 'three leaves and a bud' from six different tea plantations around the world. The tea was plucked at 7am, 12noon, 5pm and 10pm. In each location sunrise was within 2

25    hours of 7am. T.he plucked tea was then analysed for its theanine content, a major com;:- ~nent of the available amino acids. The following results were obtained.



Irocation        Time  of  plucking       
    7am.    12noon    Spm    lOpm   
                   
1    2.2    1.45    0.8    0.7   
2    1.78    0.85    0.45    0.45   
3    0.9    0.25    0.2    0.25   
4    3.85    2.2    2.1    1.65   

5    2.40    1.40    1.30    1.55
6    1.05    0.6    0.6    0.50

It can clearly be seen that the level of theanine is much greater in the morning than later in the day.

5

The tea which was plucked at 7am was subsequently processed in a conventional black tea process of withering, maceration, fermentation and firing to produce a black tea naturally high in theanine. The tea was packaged into 50kg sacks and marked as

10    being tea which is plucked early in the morning and being naturally high in theanine.


1.    A process for manufacturing amino acid-rich tea or tea extract using tea starting material comprising at least 50wt% of tea plant material harvested within 3 hours before

10    and after sunrise and then processing the tea in a conventional tea process and packaging to provide a vendible tea product comprising at least 50wt% of tea plant material harvested within 3 hours before and after sunrise.

15 2. A process according to claim 1, wherein the starting material and/or the packaged product comprises at least 60wt% of tea plant material harvested within 3 hours before and after sunrise.



20 3. A process according to any preceding claim, wherein the starting material and/or the packaged product comprises at least 70wt% of tea plant material harvested within 3 hours before and after sunrise.


25    4. A process according to any preceding claim, wherein the processing comprises at least one step selected from withering, maceration, steaming, grinding, fermentation, firing, sorting, infusing.


30 5. A process according to any preceding claim, wherein the tea is infused in water to produce an aqueous infusion of tea solids.


6.    A process  according  to  claim 5,  wherein  the  infusion  is

35    concentrated and/or dried to produce a amino-acid rich tea concentrate comprising from 100 to 50 wt% tea solids.

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