A project report on

Acidity , presence of inorganic elements & quantitative analysis of alkaloids present in tea leave

Submitted by-Hemonta BorthakurManash Jyoti BaruahMriganka ChalihaPranjal Protim KonwerManuj GogoiManash Jyoti Gogoi

POINTS 1.Introduction2.Objective3. Acidity4.Elements present(generally)5.Alkaloid studied6.Application of alkaloids7.Experimentals8.Result and discussions9.Conclusion10.Acknowledgement11.Reference

CONTENT

Generally there are several minerals or elements such as Fe, K, Mg, P, S, Zn, Ca ,Na , Mn etc. and some alkaloids are presents in tea leaves. The acidity which makes the taste of tea sour, also vary with places. All these depend upon the soil, the minerals, alkaloids present in tea leaves. Assam is the largest producer of tea in India (about 53% of the total tea production). Suitable land and climate conditions provide favorable environment for tea cultivation in Assam. Amongst the minerals and essential trace elements present in tea leaves, Caffeine constitute about 3% of tea’s dry weight. Small amount of tannin is also present in tea leaves. Because of modern environmental pollution, F and Al also sometimes occur in tea. It also contains diverse polyphones including flavonoids and catechins .Tea contains a variety of naturally acidic and basic compounds which interact to form a mildly acidic solution.

INTRODUCTION:

Analysis of tea leaves for -Acidity - presence of inorganic elements -quantitatively the amount of

tannin and caffeine

Objective

Tea is not an acidic enough to cause any harm. Highly acidic food and drink can contribute to tooth decay and digestive upset. Acidity is usually measured by pH. Higher is the acidity sour is the taste of tea.

Acidity

The major inorganic elements present in an ideal tea leaf are Ca, Cu, Fe, K, Mg, Zn, P, S etc.

Elements present(generally)

Alkaloids studied

Caffeine Tannin

Caffeine is a naturally occurring xanthine derivative.Xanthine occurs in tea extract and animal tissues which is a hydroxy purine.

Tannins are class of compound in tea, especially black tea, which tend to have a bitter flavour and astringent property. Tannins are naturally occurring plant polyphenols

Tannin

Caffeine

-in medical field-used as an food

ingredient-used as a water pill

Tannin

-in medical field-used as a flavoring

agent-in manufacturing

ink

Applications of studied alkaloids

1)Determination of acidity of tea: Materials and chemicals used :- Tea extract, N/50 NaOH, phenolphthalein, burette ,

pipette and conical flask Observation

Experimentals

Sl no.

Tea leaves Initial reading

Final reading(ml)

Volume of N/50 NaOH(ml)

Ph calculation

1 Amguri tea(dry)

0 3.7 3.7 2.1

2 Rajmai tea(dry)

0 2.4 2.4 2.3

3 Amguri tea(raw)

0 3.4 3.4 2.2

4 Rajmai tea(raw)

0 2.1 2.1 2.4

2)Detection of inorganic elements

-By using the methods of qualitative inorganic analysis for the tea leaves of Rajmai Tea Estate & Amguri Tea Estate, we have found the presence of following elements in the two different tea samples, as:

Sl no. Tea samples Inorganic elements present

1 Amguri tea(raw) Fe, Cr, Mn

2 Amguri tea(dry) Fe, Cr

3 Rajmai tea(raw) Fe, Cr, Mn, Ca

4 Rajmai tea(dry) Fe, Cr, Ca

i)TanninMaterials & reagents used: Tea extract, Conical flask,

beaker, funnel, distilled water and calcium carbonate

Table:

3)Extraction

Sl No. Tea sample Wt. of tea

Wt of calcium tannate

%ageW2/W1x100

1 Rajmai tea(raw) 10gm 0.6gm 6%

2 Rajmai tea(dry) 10gm 0.24gm 2.4%

3 Amguri tea(raw) 10gm 0.144gm 1.44%

4 Amguri tea(dry) 10gm 0.223gm 2.23%

(i) Materials & Reagents used: Tea extract, distilled water ,lead acetate, sulphuric

acid, animal charcoal, chloroform, separating funnel, funnel,beaker etc.

Table:

ii)Caffeine

Sl no.

Tea sample Wt. of tea sample(W1)

Wt. Of caffeine obtained(W2)

Percentage(%) (W2/W1)x100

1 Rajmai tea(raw) 10gm 0.09091gm 0.9091%

2 Rajmai tea(dry) 10gm 0.15909gm 1.5909%

3 Amguri tea(raw) 10gm 0.17045gm 1.7045%

4 Amguri tea(dry) 10gm 0.13636gm 1.3636%

The tea leaves of different places have different acidities and contain various alkaloids and inorganic elements. But, there are some alkaloids and elements that are common in tea leaves of all regions.

From our data, we came to know that the acidity of dry leaves is more than that of raw leaves. So, it would be good if we use raw leaves for drinking tea but there are some difficulties such as packaging problems, addition of preservations etc.

The amount of caffeine present in the tea leaves of Amguri tea estate is more compared to the amount in Rajmai tea estate. So, the tea of the Amguri tea estate will be more bitter than the tea of the Rajmai tea estate.

Similarly, the amount of tannin present is more in the tea leaves of Rajmai tea estate than Amguri tea estate. So, the leaves of Rajmai tea estate will have good astringent property.

Result and Discussions:-

We have collected the leaves from the plant Camellia Sinensisuar Assamica (Masters) collected from two recognized tea estates (Amguri Tea Estate & Rajmai Tea Estate) and use these leaves for some investigational experiments to determine the qualities of the tea obtained from the two estates.

We have analyzed the different tea leaves for different inorganic elements present in them. We have also studied the acidity of tea leaves and amount of purine alkaloids (Caffeine & Tannin) present in those two tea samples.

From the analysis, we may conclude that the tea obtained from Rajmai Tea Estate & Amguri Tea Estate are suitable for human health and quality tea productions are generated from this two recognized tea estates.

Conclusion

At the very outset, we would like to offer our sincere thanks and gratitude to Dibrugarh University for including a project work in B.Sc semester syllabus. We would like to offer our grateful thanks to Mr. Diganta Borah, Head of the Department of Chemistry, Sibsagar College, Joysagar, for his constant inspiration to do such a research project and also to provide the laboratory facility for our project work. We highly thankful to our project guide Mrs. Yasmin Begum, Assistant Professor, Department of Chemistry, Sibsagar college, Joysagar for her valuable suggestion and guidance without which we are unable to complete our project work. We also convey our special thanks to our friends for helping in the project.

ACKNOWLEDGEMENT

(i) Agarwal O.P. , Organic Spectroscopy: Natural Products,volume 1, ,42nd edition(page no:- 523)

(ii) Chatwal R. Guedeep Organic chemistry of Natural Products, volume1, (section:-4.13)

(iii) en.m..wikipedia.org/wiki/caffeine.(iv) www.caffeineinformer.com/the-caffeine-database(v) www.thefragrantleaf.com/caffeine and tea(vi) www.teatulia.com/tea.../caffeine-in-tea(vii) www.agriculture.journals.cz/.../08057.pdf(viii) www.academic journals.org(xii)En.m.wikipedia.org/wiki/tannin(xiii)www.merriam-webster.com/.../tannin(xv)www.fmltea.com/teainfo/caffeine-tannin

Reference

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