Title of Invention

A PROCESS FOR PREPARATION OF GREEN TEA USING INFRARED RADIATION

Abstract This invention relates to a process for preparation of green tea using infrared radiation. The process in particular, describes the method of manufacture of green tea using infrared drying. In the process, Fresh, fine picked green tea leaves are Withered, Enzyme inactivated using Infrared dryer, cooled to obtain the green tea. The novelty of the process lies in employing the infrared energy for enzyme inactivation in tea leaves during the manufacture of superior green tea.
Full Text This invention relates to a process for preparation of green tea using infrared radiation. The process in particular, describes the method of manufacture of green tea using infrared drying.
Tea is one of the popular beverages in the world. Black tea, green tea and oolong tea are the major types of teas in demand. India produced 826 million Kg of tea in the year 2002. India accounts for 30% of the world production and 24% of the world consumption of tea. The Indian tea exports stand close to 200 million Kg. Low priced teas from other countries are giving stiff competition. The recent research findings are ascribing several health benefits to tea. Green tea being a rich source of polyphenols is having better potential for these health benefits.
The green tea has showed effects in controlling hypertension, cardiovascular diseases, dental caries and some types of cancer. The polyphenols like flavanols, flavanol gallates, flavanol glycosides, bisflavanols, epitheaflavic acid and gallic acid, have a variety of pharmacological activities. The polyphenols possess the property of strengthening the walls of blood vessels and regulating their permeability and the substances responsible for this action are designated as 'Vitamin P'. The other effects of tea flavonoids include increasing the levels of catecholamines, the capillary strengthening action, the antiinflammatory action, normalisation of thyroid hyperfunction, protection against the harmful effects of exposure to radiation, bacteriostatic effect on a number of microorganisms and stimulation of folic acid biosynthesis.
Phenolic pigments are abundant in green tea. They contain an anticoagulant enzyme that keeps the blood flowing smoothly. Recently, it has been reported that a spray prepared from the tannins of tea is able to cure the allergy (asthma) caused by mites present in the air. This is supposed to have a permanent cure as against the use of cartico-steroids whose effects are only temporary. Another recent report says that drinking at least one cup of green tea per day will prevent the occurrence of cancer.
Many laboratory studies have demonstrated inhibitory effects of tea preparations and tea polyphenols against tumor formation and growth. This inhibitory activity is believed to be mainly due to the antioxidative and possible antiproliferative effects of polyphenolic compounds and in particular the major catechins EGCG, EGG, EGG and EC in green tea. The major constituent and possibly the most powerful of these catechins is EGCG. These catechins may also inhibit carcinogenesis by blocking the endogenous formation of N-nitroso compounds, suppressing the activation of carcinogens, and trapping of genotoxic agents.
During the processing and then storing, certain off flavours along with desired flavours develop in the black tea. 'Green note' is one such flavour. This off flavour which is developed in storage after three to four weeks from manufacture is also called 'grassy', 'fishy' or 'painty' flavour and commonly known as 'pacha taint' (Ganeshan and Ramaswamy, 1996, February, The Planters chronicle, p 91)
This type of off-flavour was reported in the Wynaad and Nilgiri-Wynaad regions during certain periods of the year in CTC teas after 3-6 weeks of storage. When the teas were fresh, professional tasters report these as normal. Pacha taint has become a serious concern for the planters and traders of tea in the Wynaad and Nilgiri-Wynaad areas. The price of the pacha-tainted tea is low, when compared to normal tea. Due to this problem, the planters are not getting suitable price for their product. This scenario has prompted us to develop a simple method for the manufacture of green tea using the fresh leaves from these regions as described under herein further.
Reference may be made to a U.S. Patent No. 5993867 (1999) by Rohdewald which relates to a process for producing a preparation containing the polyphenols of green tea, wherein green tea leaves are cooled until the activity of the enzyme polyphenol oxidase drops down to at most 1% of the value at normal temperature and immediately the water is removed from the leaves. This invention differs from the present one in methodology of drying and have drawback of high throughput cost.
Reference may be made to a PCT international patent application entitled "Process for producing green tea, oolong tea and black tea" by Takano, T and Fujiwara, K (2003) which relates to a method for improving commercial value of astringent tea leaves; wherein astringency of fresh tea leaves is controlled by adding enzymes that digest tannin, plus polysaccharides and proteins in order to relieve astringency and enhance flavour. This invention is different from present one in the treatment of tea leaves and the finished product will have different flavour profile.
Reference may be made to a report titled "New process of green tea manufacture" by Barbora, B.C. and Sana, S.C. (1995), Two and a bud ; 42(1), 12-15. A modified procedure for orthodox green tea involving steaming fresh leaf, cooling, removal of surface water and rolling and drying is described. Other method describes CTC process involving steaming fresh leaf, spreading leaf, partial drying, hot air panning, processing in CTC machine, final drying and packing. This is different from our process as processing methodology is different. The number of steps followed are more and complex compared to our process.
Reference may be made to a U.S. patent No. 6416803 (2002) by Shibata which describes a method for producing green tea in microfine powder. The process involves steaming leaf, hot air drying, twisting to form crude green tea which is further pulverized in ball mill to a micro fine powder (1ja). The microfine powder is spread in a flat box on which water is sprayed to a final moisture content of 7.5-8.0%, followed by agitation. The flat box is dried in an infrared irradiation chamber. This process is different from ours as crude dried green tea is powdered, conditioned with moisture and infrared dried again, which is very complex compared to our process.
The infrared waves actively absorb the water in tea leaves without harming its structure. Infrared waves are harmless for people and environment if used carefully.
Infrared drying effectively utilizes the energy and quickly removes moisture from food matrix. The drying of the product is possible at relatively low temperatures and in short time, which almost wholly conserves the biologically active constituents and sensory characteristics such as colour, flavour and texture.
The infrared waves actively destroy the harmful micro-flora in the product allowing long term storage of the dried product. Infrared drying allows conservation of the vitamins and other biologically active stuffs in the dried product to the level of 80-90% of the original product and also a high level of energy in the ready product.
Literature survey revealed that there is no report on the use of infrared energy for the preparation of green tea.
The main object of the present invention is to provide a process for preparation of green tea using infra red radiation.
Accordingly, the present invention provides a process for preparation of green tea using infra red radiation comprising:
a. withering the fine picked fresh tea leaves at 27-32°C for 8-18 h to
bring down the moisture;
b. inactivating the enzymes by exposure of tea leaves as obtained step
a) characterized in that with infrared dryer at 80-130 °C for a period
ranging 20-50 minutes;
c. cooling hot and dried leaves to ambient temperature for a period of
about 20-30 minutes;
d. size reduction of the dried leaves using laboratory processor;
e. packing the distorted leaves in airtight packaging material.
In an embodiment the withered and conditioned green tea leaves are subjected to enzyme inactivation by using continuous infrared dryer at 80-130 °C for a period ranging 20-50 minutes.
In an another embodiment the dried tea leaves may be subjected to cooling and size reduction using a table top mixer.
In yet an another embodiment the dried and distorted tea leaves are packaged in air tight packages.
The process for manufacture of green tea is illustrated in the following flow chart:
Fresh, fine picked green tea leaves
Withering

Enzyme inactivation (Infrared drying)

Cooling

Leaf distortion

Green tea
The novelty of the process lies in employing the infrared energy for enzyme inactivation in tea leaves during the manufacture of superior green tea.
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
Freshly picked fine green tea leaves 77 Kg were subjected to withering in troughs for 13 h at ambient conditions (with air flow from the bottom) and brought down the moisture to 56% from initial moisture content of 78%. These withered tea leaves were subsequently subjected to enzyme inactivation through infrared drying (88° C/ 40 min). The dried material was cooled to room temperature and weighed (18 Kg) and packed in polythene bags. The dried green tea has polyphenol content of 15.0% and the overall quality of the brew was rated 7.6 against 6.2 of a market sample on 10 point scale.
Example 2
Fresh green tea leaves 15 Kg were subjected to withering in withering troughs for 12 h at at ambient conditions (with air flow from the bottom) to bring down the moisture to 58% from initial moisture content of 76%. The withered tea leaves were quickly subjected to enzyme inactivation through cross flow dryer (95° C/ 4h). The dried tea 5.5 Kg after cooling was packed in polythene bags. The polyphenol content of the dried green tea is found to be 14.3%. The brew has good colour and flavour rated 6.9 against 6.2 of a market sample on 10 point scale.
Example 3
Fresh green tea leaves 50 Kg were subjected to withering in withering troughs for 11 h at ambient conditions (with air flow from the bottom) to bring down the moisture to 56% initial moisture content of 79%. The withered tea leaves were quickly subjected to enzyme inactivation through cross flow dryer (100° C/ 4h). The dried tea 13.2 Kg after cooling was packed in polythene bags. The polyphenol content of the dried green tea is found to be 14.0%. The brew has good colour and flavour rated 6.8 against 6.2 of a market sample on 10 point scale.




We claim:
1. A process for preparation of green tea using infra red radiation comprising,
a. withering the fine picked fresh tea leaves at 27-32°C for 8-18 h to
bring down the moisture;
b. inactivating the enzymes by exposure of tea leaves as obtained step
a) characterized in that with infrared dryer at 80-130 °C for a period
ranging 20-50 minutes;
c. cooling hot and dried leaves to ambient temperature for a period of
20-30 minutes;
d. size reduction of the dried leaves using laboratory processor;
e. packing the distorted leaves in airtight packaging material.
2. A process as claimed in claim 1, wherein the dried tea leaves may be subjected to cooling and size reduction using a table top mixer.
3. A process as claimed in claims 1-2, wherein the dried and distorted tea leaves are packaged in air tight packages.
4. A process for preparation of green tea using infra red radiation substantially as herein described with reference to the examples accompanying this specification.

Documents:

488-DEL-2004-Abstract-(28-08-2009).pdf

488-del-2004-abstract.pdf

488-DEL-2004-Claims-(28-08-2009).pdf

488-del-2004-claims.pdf

488-DEL-2004-Correspondence-Others-(28-08-2009).pdf

488-del-2004-correspondence-others.pdf

488-del-2004-correspondence-po.pdf

488-DEL-2004-Description (Complete)-(28-08-2009).pdf

488-del-2004-description (complete).pdf

488-DEL-2004-Form-1-(28-08-2009).pdf

488-del-2004-form-1.pdf

488-DEL-2004-Form-18-(12-09-2006).pdf

488-DEL-2004-Form-2-(28-08-2009).pdf

488-del-2004-form-2.pdf

488-DEL-2004-Form-3-(28-08-2009).pdf

488-del-2004-form-3.pdf

488-del-2004-form-5.pdf


Patent Number 257908
Indian Patent Application Number 488/DEL/2004
PG Journal Number 47/2013
Publication Date 22-Nov-2013
Grant Date 19-Nov-2013
Date of Filing 16-Mar-2004
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESARCH
Applicant Address RAFI MARG, NEW DELHI-110001, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 BABASAHEB BHASKARRAO BORSE CENTRAL FOOD TECHNOLOGICAL RESEARCH INSTITUTE, MYSORE, INDIA.
2 LINGAMALLU JAGAN MOHAN RAO CENTRAL FOOD TECHNOLOGICAL RESEARCH INSTITUTE, MYSORE, INDIA.
3 BASHYAM RAGHAVAN CENTRAL FOOD TECHNOLOGICAL RESEARCH INSTITUTE, MYSORE, INDIA.
4 GURUGUNTLA SULOCHANAMMA CENTRAL FOOD TECHNOLOGICAL RESEARCH INSTITUTE, MYSORE, INDIA.
5 MYSORE NAGARAJA RAMESH CENTRAL FOOD TECHNOLOGICAL RESEARCH INSTITUTE, MYSORE, INDIA.
PCT International Classification Number A23F 3/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA