Two and a Bud 59(2):126-129, 2012

RESEARCH PAPER

An integrated approach to the extraction of natural tea color, flavor andevaluation of antioxidant properties of tea

S. Baruah*I,A.K. Bordoloi*,R. C. Gogoi', M. K. Gogoi* and M.Hazarika**BiochemistlY Department, I Tea Processing and Manufacturing Advisory Department, Tea Research Association, TocklaiExperimental Station,Jorhat-785008, Assam, India.

ABSTRACT

An 'integrated approach has been made for ttre..extraction of natural color and.flavour from tea. Water extraction was made,concentrated in thin film ev.apDrator and spr.ay tiried. The spray dried sohtbl.etea powder can be used as color additive indiffur:ent food pr61du.c.ts.WhLleconcentratiQg, the distillate,obtained hasJtig'b tea flavour which can be used for thepreparation of different bever~es. 'Jihe antiom:dant pnoperty of green and1blac.k1eas as well as of.soluble green and blackteas was also evaludnd.

JNTROI)LlCTION resl"onsible far colour, taste 'and flavQur of tea, works ofHazarika et a/. (2002) have lneen quoted((Tables 1,2 and.3).

Talll:e ]. Bioch.emical compollln.d~ responsi.ble ,for colour (ofliquor

Table 2. Biodlemical compounds responsible for u..te

Tea is :an <aqueous infll,~Ml of dried leaves of tlte plantCamillilll.'I,'inensis and the most widely((;onsumed bev,orageor drink iJrn tfhe world becaIJl5eof its attractive color, spt}ciaJflavor and ii:tsstimulating effect on human body (HarbG"'Yand Balentme, 1997). There Me three types of tea: Grecntea, Go long rea and Black tea. The manlllfucturing systemis somewhat different for each of the basic types of tea

Green tea undcr-,goesno or little fermentation, Golong tea ispartially fermented and black tea is produced as completetea fermentation. As their fermentation type and times aredifferent, the chemical composition will also De different.

Tea contains number of chemical components, some areresponsible for colour, some are responsible for fiavor andsome for taste of the liquor (Harbowy and Balentine, 1997,Hazarika et aI., 2002). Many ofthese are antioxidants andexhibit medicinal properties. It also contains different typesof amino acids and phenolic components, which areresponsible for taste of the liquor (Harbowy and Balentine,1997). The chemical components which are responsible forcolour, flavour and taste are shown in Tables I to 3 (Hazarikaet al., 2002).

COtt!ljpl0lltldsThe iItlwvi ns

Theafimvin gallates

Thearuhigins

Flavaooll,glycosid es

PheopholJibide

Pheoph)1inCarotene

Compounds

PolyphenolsAmino acids

CaffeineTheatlavills

Theatlavin + catfeille

Thearubigin groups I & 2

Thearubigin groups 3

Colour

Yellowi!!ihllbro,wll

Golden ycillowReddish t)llrO\vn

Light yeJio'wIffirowilishImlackish

Y.ellowish

Taste

Astringent

BrothyBitter

AstringentBrisk

Ashy

Slight astringent

The objective of this investigation was an integratedapproach to the extraction of natural colour, flavour andantioxidant from the single source i.e. from green and blacktea. To have an idea about the chemical compounds

I Corresponding author: sabitribaruah@yahoo.com

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The main idea of diversification is the extraction of

byproduct and transformation to value-added product, sothat tea becomes more remunerative (Baruah et al., 2005).

Normally for diversified work tea waste, low quality tea,pruning litter etc were used as source materials, but this

Table 3. Biochemical compounds responsible for flavour

CompoundsLinalool

LinalooloxideGeraniol

Phenyl acetaldehydeNerolidol

Benzyldeh yd e

Metllyl salicylate

Phenyl ethanolTrans- 2-hexena I

N-hexanal

Cis-3-hexenol

~-io noneCitral

Limonene

Butyric acid

Flavour

Sweety

Floral

FruityBitter almond

Winter green

Grassy

Fresh tlavour

Lemon

Lemon

Ranc id bu tter

Experimental Station, lorhat, during the month of Marchand April and they are mixed in different proportions. Fromthese fresh leaf samples green tea as wel\ black tea wasmanufactured.

Manufacture of black tea

Black tea was manufactured in the Model Tea Factory ofTocklai Experimental Station by using traditional method.

Manufacture of green tea

Green tea was manufactured in the BiochemistryDepartment ofTocklai Experimental Station by followingmethodology ofBaruah et al. (2009).

Preparation oftea colour and tea flavour

year we made an attempt for extraction of tea componentfrom tipping leaves which have also the adequate amountof quality attributes.

Color is an important quality attribute. There is anincreasing demand of natural food color all over the world.Tea is a source of natural color. Extraction of colored

components of tea and incorporation of them into somefood products will make tea more remunerative. It will notonly make tea remunerative but also produce some newtea-based food products with high antioxidant value.

Though we made so many attempts to extract colour andflavor of tea, no integrated approach was made to theextraction of these components from the same source. Herean integrated approach has been made to the extraction ofnatural tea color and flavor of tea from the same source.

Water extraction from green and black teas were made andconcentrated in thin film evaporator under vacuum and atcontrol temperature and spray-dried.

Known amount of black tea, collected from the Tea

Processing and Manufacturing Advisory Department,Tocklai, was taken in a beaker and infusion was preparedby using boiled distilled water and filtered. The filtrate ofthe tea extract containing the chemical componentsresponsible for colour, flavour and taste ~ere concentratedin thin film evaporator using vacuum at controlledtemperature, where the filtrate was concentrated by filmformation. (Baruah et al., 2005)

Some amounts of tea concentrate were spray-dried in aPilot Scale Spray Drier and obtained soluble black teapowder. The spray-dried soluble tea powder obtained [Tomblack tea was of brown to reddish brown in color.

Soluble green tea powder was also prepared by using thesame procedure as black tea powder. The tea powderobtained from green tea was of pale yellow to yellowishgreen in colour.

The conditions of thin film evaporator are:

The conditions of spray drying are:Temperature: Inlet- 175°C-195°C

Outlet - 90°C-] OO°C

Pressure: 325 - 350 psi

While concentrating the tea extract in thin film evaporatorthe distillate obtained had high tea flavour. The flavor thusextracted could be used for the preparation of differentbeverages like green and black tea soft drink and teaflavored milk ,tea ice cream etc. Both green and black teapowder and tea concentrates could be used as a naturalcolor additive in the preparation of different tea-based foodproducts such as confectionary and bakery items. Theantioxidant property of green and black tea as well as greenand black soluble tea was also evaluated.

TemperaturePressure

Rpm

45-60°C60 hPa

500 (Stire speed)

MATERIALS AND METHODS

Collection of samples

The two and a bud shoots of the clones T.3E/3, S.3A/3 and

TV I were collected from the experimental garden of Tocklai

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Chemical analysis

For chemical analysis, each parameter was replicated thriceand the mean was calculated.

Moisture of green tea and black tea as well as soluble teasamples was determined using standardized procedures ofAOAC (1980).

Polyphenols were extracted with 70% methanol at 700C anddetermined colorimetrically using Folin - Ciocalteu phenolreagent, using the methodology BS ISO 14502 -1 :2005.

Theaflavins (TF) were estimated by using the methodologyofUllah (1986).

Total antioxidant activity offresh tea leaves was estimatedby DPPH using the methodology of Gad ow eta!. (1997).

Soluble tea as natural colour

Incorporation of soluble tea as natural colour in different

food products

From the quality evaluation of both green and black solubletea by different consumers using hedonic rating scale (Fig.I) it was found that in case of overall acceptability of greenand black soluble tea T3 got the highest score. Comparingthe black and green soluble tea it was found that the overallacceptability of soluble green tea was more than solubleblack tea which was in conformity with the taster'sevaluation

The tea taster evaluated different quality parameters suchas colour, brightness, briskness, strength and quality (Fig.2) of soluble green and soluble black tea and it was foundthat the quality of both green and black soluble tea wasbetter (T2). The soluble tea was prepared by using inlettemperature of 185°C. In case of quality the green solubletea scored better than soluble black tea.

Incorporation of both green and black soluble tea coloursin different confectionary and bakery items was highlyacceptable. The antioxidants present in tea were alsoincorporated in different food products.

Table 4. Mean percentages of moisture, theaflavin,caffeine, total polyphenol and antioxidant indifferent kinds of tea

Quality evaluation

The quality of soluble green and black tea wasorganoleptically evaluated by different consumers using9-point hedonic rating scale and by Tocklai tea taster.

Attributes

MoistureThe aflavinCaffeine

Total polyphenol

Antioxidant activity

Green Solubletea

green tea5.20

4.64

3.92

7.0029.3 5

40.2484.68

79.29 Blacktea

4.711.384.03

12.13

74.35

Solubleblack tea

4.083.797.15

24.1671.96

RESULTS AND DISCUSSION

Fig. I. Quality evaluation of soluble green tea and solubleblack tea by Hedonic rating scale

-(\""-...:

.",.•..."''''1\

.~,..~••",11101)

.C~~

f'il\·~.~..~. Ml~, .'''I''~'

T.\1'1

I I I I IR

n I "iS.~ll>"i!r"'\ ,••

Fig. 2. Quality evaluation of soluble green tea and solubleblack tea by tea taster

From Table 4 it is observed that the moisture contents of

different tea samples were in acceptable stage and theaverage value of theafavins in black tea was 1.38 and insoluble black tea it was 3.79 (Fig. 2). In soluble black tea thecaffeine content was as high as 7.15 percent followed by 7percent in green soluble tea. The green tea and black teacontained 3.92 and 4.03 percent respectively. It was foundthat the mean value of total polyphenols was higher ingreen tea than in black tea. But soluble green tea containedthe highest amount of polyphenol. Black tea contained theleast amount of the same. The antioxidant activity of greentea was higher than black tea. Since the polyphenols arethe major antioxidants present in tea, the low amount ofpolypenol and antioxidant activity of black tea was due tothe degradation of antioxidants present in green tea duringprocessing of the same to black tea. Similarly the antioxidantactivities of soluble green tea and soluble black tea wereless than green tea and black tea (Table 4). This could bedue to their thermal degradation during processing at highertemperature of spray drier.

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CONCLUSION

o Extraction of by-products and their transformation tovalue-added products will make tea more remunerative

o The green and black soluble tea powders prepared byspray dryer method have high antioxidant values

o The soluble tea powders can also be used as a naturalcolour additive in different food products

o Soluble tea can be used as beverage

o Antioxidant property of different diversified productswas found to be positively correlated with the amountof antioxidant present in it

REFERENCES

AOAC,( 1980). Official Methods of Analysis. 13th edition.Association Of Official analytical Chemist.Washington D.C. pp. 376-384

Baruah, S., Boithoque, P., Yadav, N., Bordoloi, P. andHazarika, M. (2009). Study of PolyphenolicComponents in Tea and its Utilization in theDevelopment of Tea-Flavoured Milk. Two Bud,56(1&2):37-41.

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Baruah, S., Tamuly, P.K, Bordoloi, P., Bordoloi, A.K.,Sabhapondit, S., Gogoi, R.C, Kalita, IN., Bhuyan,L.P., Gogoi, M.N. and Hazarika, M.(2005), Technology for Product Diversification andValue Added Items of Tea. 34th Tock. Conf., 28-30November. pp.63-70.

BS ISO 14502-1 :2005. Determination of total polyphenolscontent in tea - Colorimetric method using Folin­Ciocalteu reagent.

Gadow, V, Turkmen, N. and Sari, F.(1997). Effect of extractionsolvents on concentration and antioxidant activityof tea polyphenols determined by DPPH.99(4):835-41

Harbowy Methew, E. and Balentine Douglas, A. (1997). Teachemistry. Critical Reviews in Plant Science.ppA15-80

Hazarika, M., Goswami, M.R., Tamuly, P., Sabhapandit, S.,Baruah, S. and Gogoi, M.N. (2002), QualityManagement of Tea -Biochemist's view. Two Bud,49:3-8.

Ullah, M.R. (1986): A rapid procedure for estimatingTheaflavins and Thearubigins of black tea, Two

Bud. 33(1&2):46-8.