AMOUNT OF VITAMIN C IN DIFFERENT FLAVOURS OF MARIGOLD YOGURT DRINK’S

VANITHA A/P GANISONTHILAGA A/P VIREN

HEMALATHA A/P MEGANATHAN

6AS1

SMK DARUL EHSAN SELAYANG BHARU

ABSTRACT

CHAPTER 1

INTRODUCTION TO TITLE

1.1 INTRODUCTION

The various flavour of yogurt drinks available in markets are made from different types of

fruits such as apple kiwi, tropical fruit, mango, strawberry and mixed berries. The main

nutritional value of these drinks is their vitamin C content. Yogurt, like all fermented food, is

teeming with healthy bacteria. This beneficial bacteria, is very good for the body’s immune

system. Yogurt drinks are rich in vitamin C as it flavoured with various fruits. Vitamin C is a

water-soluble compound that is essential for life. Vitamin c is a powerful antioxidant and is

required for several metabolic processes.

1.2 LITERATURE REVIEW

Vitamin C is sensitive to light, heat and air. (Alpert, 1997-2004 ) Vitamin C is

the most easily destroyed vitamin and it is easily harmed during food preparation.

This can happen during chopping, exposure to air, cooking, and boiling. (Joanne

Larsen, 1995-2003). There are many factors that will affect how much vitamin C is

in orange juice. Townsend (1999) summarized some these factors. For example,

freezing preserves vitamin C.

Significant variation for vitamin C has been found in nutritional drinks, diet

products, and beverages which seemed to be a result of manufacturing practices

(Hidiroglou et al. 1997). Vitamin C levels in food vary considerably due to factors

which include species,maturity, portion, soil, climate, season, diet, storage, handling,

method of preparation and consumption (Pennington 1975).

Suntornsuk et al.,(2002) determined vitamin C in fresh and freeze dried

herbal juices using direct titration method with iodine solution in acidic potassium

iodide. The iodine solution was standardised used primary standard arsenic trioxide.

Guava and emblic myrobolan have higher vitamin C content compared to sweet

pepper, passion fruit and lemon

1.3 PROBLEM STATEMENT

1.4 OBJECTIVE OF RESEARCH

1. To determine the amount of vitamin C in five different flavoured commercial yogurt drinks using titration.

2. To compare the amount of vitamin C determined in five different flavoured yogurt drinks.

CHAPTER 2

METHODOLOGY

2.1 APPARATUS AND MATERIALS

Apparatus

50 ml beaker

250 ml conical flask

Burette

Retort stand

100 ml, 200 ml and 1L volumetric flask

25 ml pipette

10 ml and 100 ml measuring cylinders

Dropper

Tripod stand

Bunsen burner

Wire gauze

Glass rod

Materials

Distilled water

1L of iodine solution 0.005 mole

Starch indicator solution

Potassium iodide

0.25g of soluble starch

Yogurt drinks : - Apple kiwi

- Tropical fruits

- Mango

- Strawberry

- Mixed berries

2.2 PROCEDURE

PREPARATION OF 0.005 MOL OF IODINE SOLUTION

1. 2g of potassium iodine weighed and transferred into a 100ml beaker.

2. 1.3 g of iodine weighed and added into the same beaker.

3. A few ml of distilled water added and swirled for a few minutes until iodine is

dissolved.

4. Iodine solution is transferred into a 1L volumetric flask, making sure to rinse all

traces of solution into the volumetric flask using distilled water.

5. The solution made up to the 1L mark with distilled water.

PREPARATION OF 0.5% OF STARCH INDICATOR SOLUTION

1. 0.25g of soluble starch is weighed and added into 50ml of near boiling water in a

100ml conical flask.

2. The solution stirred to dissolve and cool before using.

TITRATION

1. Filter funnel was used to pour approximately 3ml of 0.005 mol of iodine solution in

the burette, with the stopcock closed, while holding it in a nearly horizontal

position and the solution was rolled around in order to wet the entire inner surface

of burette.

2. Then the iodine was drained out of the burette by opening the stopcock.

3. The stopcock was closed and burette was filled up with approximately 50ml of

iodine solution with 0.005mol. The initial volume of iodine solution in the burette

was recorded.

4. 50ml aliquot of the apple kiwi flavoured yogurt drink solution was pipetted into a

250ml conical flask and about 100ml of distilled water and 1ml of starch indicator

solution was added.

5. The sample was titrated with 0.005mol iodine solution. The endpoint of titration is

identified as the first permanent pale blue colour due to the starch iodine complex.

6. The final volume of iodine in the burette was recorded.

7. The titration was repeated with other flavoured yogurt drinks added with starch,

the initial volume and final volume of iodine in the burette was recorded to

determine the amount of iodine used for each titration.

8. The initial volume was substracted from the final volume to determine the volume

of iodine solution added to completely oxidized the vitamin c in the yogurt drinks.

9. The result was recorded in a table and graph was plotted.

CHAPTER 3

RESULTS AND DISCUSSIONS

1.1 OBSERVATION AND RESULTS

Apple Kiwi

Experiment 1 2 3

Initial volume / ml 50.00 50.00 50.00

Final volume / ml 40.00 36.00 35.00

Titre (ml ) 10.00 14.00 15.00

Average 13.00

Tropical fruit

Experiment 1 2 3

Initial volume / ml 50.00 50.00 50.00

Final volume / ml 38.00 40.00 34.8

Titre (ml ) 12.00 10.00 15.20

Average 12.40

Mango

Experiment 1 2 3

Initial volume / ml 50.00 50.00 50.00

Final volume / ml 42.40 43.00 43.50

Titre (ml ) 7.60 7.00 6.50

Average 7.60

Strawberry

Experiment 1 2 3

Initial volume / ml 50.00 50.00 50.00

Final volume / ml 45.50 46.50 46.50

Titre (ml ) 4.50 3.50 3.50

Average 3.83

Mixed berries

Experiment 1 2 3

Initial volume / ml 50.00 50.00 50.00

Final volume / ml 39.00 40.00 34.70

Titre (ml ) 11.00 10.00 15.3

Average 12.10

1.2 INTERPRETATION AND DISCUSSION

CHAPTER 4

CONCLUSION

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