1. Label using sticker papers on the five beakers with different temperatures such as 10.0oC, 25.0oC, 40.0oC, 55.0oC, 70.0oC. Then, add 10 cm3 of distilled water, measured using measuring cylinder, into each beaker.
2. Use cork borer, prepare five uniform beetroot/ dragon fruit cores with diameter of 12mm by pushing the cork borer into the beetroot/ dragon fruit and then, use spatula to take out the cylindrical cores that is inside the cork borer.
3. Cut the cylindrical cores carefully into 3 cm in length, using spatula and ruler for measuring, on the white tile.
4. Add plenty of distilled water into another beaker. Then, put the cores into it for 1 minute to wash away the pigments that are leaked out due to the damage of plasma membranes when cutting.
5. Remove the beetroot cores from the distilled water using forceps and dry them gently on the tissue.
6. Next, fill the water bath with distilled water and adjust it to have temperature as required with the help of thermometer to ensure it is the right temperature.
7. Place one beaker in the water bath. Then, prepare stopwatch at one of the hand so that time could be started when the core was added into the beaker.
8. After 8 minutes, use forceps to remove the core immediately to prevent further leakage of pigment from the cores. And, shake the beaker gently to make sure that the pigment is well mixed with the distilled water.
9. Next, set the colorimeter by plugging in the interface to the laptop and press on.
10. Then, connect the colorimeter sensor to that interface.
11. Select the proper data-collection software with appropriate filter.
12. Place another cuvette that was filled with distilled water into the colorimeter to set the absorbance value into zero.
13. Then, decant 3 cm3 of the pigment liquid from each beaker into the cuvette. Put a piece of white paper behind the cuvette to make it easier to see and compare the depth of the liquid colour.
14. Last, place the cuvette in the colorimeter and record the readings for absorbance.
15. Repeat the same steps to carry the other trials.