Exp 1: Determination of heat stability of vitamin C

Burette Conical flask Volumetric flask Measuring Cylinder Measuring Cylinder Micro Pipette

Step0: Glassware & Chemical reagents required

Standardization of DCPIP Dye solution

Step1: Take 5 ml of standard ascorbic acid solution in the conical flask

click to suck ascorbic acid click to pour in conical flasks

Step2: Add 5 ml of HPO3 solution in the conical flask

click to suck HPO3 click to pour in conical flasks

Step3: Titrate the mixture with DCPIP dye solution

click to place funnel click to pour in dye click to remove funnel click to place flask start titration stop titration
Sample Titrant used
standard sample

Titration Completed

Step4: Calculation of Dye factor

Titrant Used =

Dye Factor =
0.5
Titrant used
Dye Factor =
0.5
= 0.08

Analysis of sample

Step5: Selection of sample

select this sample
select this sample
select this sample
select this sample

Step6: Take out 50 ml juice in four different conical flasks marked as J1, J2, J3, J4

Fill J1 Fill J2 Fill J3 Fill J4

Step7: Heat the J2, J3, J4 sample at 60, 75, 90°C respectively for 10 minutes.

Turn on Place J2 Place J3 Place J4
PT 00℃
ST 00℃
10:00

Step8: Pipette out 10 ml juice from each sample flask and pour to other four flask

Pipette out J1 Pipette out J2 Pipette out J3 Pipette out J4

Step9: Add 90 ml of 3% HPO3 solution in each conical flask.

Add in J1 Add in J2 Add in J3 Add in J4

Step10: Titrate each sample with DCPIP dye solution to a pink color which persists for 15s observation

Place funnel Pour Dye Remove funnel Tirate J1 Tirate J2 Tirate J3 Tirate J4 start titration stop titration

Titration Completed

Sample Titrant used
J1
J2
J3
J4

Calculation & Result

Sample Name Treatment Titrant Used
J1 Fresh
J2 Heated at 60C for 10 min
J3 Heated at 75C for 10 min
J4 Heated at 90C for 10 min
formula

Ascorbic Acid Quiz

Round the calculation by 2 digits then check answers

Inference

The results indicated that the amount of ascorbic acid (Vitamin C) decreases as the heating temperature of the sample increases.
It shows that vitamin C is heat sensitive vitamin and degradated with temperature.