DETERMINATION OF VITAMIN C

IODINE TITRATION

GROUP MEMBERSNAME MATRIC NUMBER

WAN MIMI SHARMILA WAN MOHD ZIN D20091035101

SITI MARDIAH BT MOHD BAHARI D20091035103

UMMU AIMAN BT ABDULLAH D20091035104

NUR HATIKAH BT MOHAMAD D20091035115

NOR’ATIKAH BT ABD.RAZAK D20091035138

INTRODUCTION

• Vitamin C or ascorbic acid is important to the body for prevention of scurvy.

• Scurvy is caused by lack of vitamin C in the body which can affect muscles weakness, swollen and bleeding of gums, loss of teeth and bleeding under the skin as well as tiredness and depression.

STRUCTURE OF VITAMIN C

• The labels on fruit juice package may be misleading as the companies may underestimate or overestimate the actual content.

• Thus, the problem is that the consumers do not know the actual amount of vitamin C in the fruit juices, unless the amount of vitamin C is stated on the label of the package.

OBJECTIVE

• To determine the amount of Vitamin C of Tropicana Twister (Orange flavor) in three different condition.

HYPOTHESISMETHOD Hypothesis

Raw(27°C) The amount of experimental Vitamin C is same with the nutritional label stated for the sample used.

Boil (80°C) The amount of experimental Vitamin C is lower if compared with the nutritional label stated for the sample used.

Freeze(4.0°C) The amount of experimental Vitamin C is same with the nutritional label stated for the sample used.

VARIABLESVariables

Fixed Type of sample usedVolume of sample used

Manipulated Temperature (80°C, 27°C, 4°C)

Responding Amount of Vitamin C

METHOD

Prepare 3 samples of TropicanaTwister Orange with 30mL each

Put 1 sample in ice bath until the temperature

drop to 4°C.

Put 1 sample on hot plate until the temperature

rise to 80°C.

1 sample on table in room temperature 27°C.

Titrate each sample by using iodine

• Add two drops of 0.1 M HCl and 5 mL of starch into each sample.Titrate by using iodine until the Color turn into blue black.• Measure the volume of iodine used.

RESULTMethods Volume of Iodine

Used(mL)Amount of Vitamin C (g)

Raw (27°C) 4.5 0.072

Boil (80°C) 3.9 0.0624

Freeze (4°C) 4.0 0.0640

Ascorbic acid (Standard)

12.5 0.2000

CALCULATION OF STANDARD

• 0.2 mg/mL ascorbic acid=12.5 mL iodineX= Volume of Vitamin C

(experimental)X= 0.2 mg/mL x Volume of

Vitamin C (experimental)12.5 mL iodine.

X= Amount of Vitamin C

DISCUSSION

• Effect of vitamin C content in fruit juices were type of storage.

• Type of storage is fruit juices must store at cool temperature. When the fruit juices are store at cool temperature, the vitamin C content does not loss.

• But at higher temperature, vitamin C content will be lost in fruit juices. This is because the vitamin C is more sensitive to temperature.

CONCLUSION

Amount of Vitamin C for raw sample isthe highest. The amount of Vitamin C forfreezed sample is higher than the boiledsample.

Boil< Freeze < Raw

• Vitamin C is damaged by heat by increasing its rate of oxidation.

• freezing can also negatively effect Vit C if the tissues of the product have been broken and exposed to air.

• room temperature is best to store it,