To begin, add 50 milliliters of sodium phosphate buffer to one gram of Gracilaria gracilis. After homogenizing the mixture, use a mortar and pestle to macerate the sample for 10 minutes. Transfer the solution to a tube and centrifuge it for 20 minutes at 12298g.
After combining the supernatant, slowly add 65%ammonium sulfate, then pellet the precipitate by centrifugation and dissolve it in distilled water. Perform dialysis of the extract using a tubing membrane against water for 24 hours, followed by freeze drying. To incorporate the extract, mix it in yogurt at a concentration of 0.21%Store the samples in individual glass flasks at 4 degrees Celsius until analysis.
To check the color stability of the extract in yogurt, calibrate the colorimeter using a white ceramic plate. Fill a cell with approximately 28 grams of the sample and analyze its color. The color stability of the yogurts with pigment was evaluated for 12 days at 4 degrees celsius.
The incorporation of the extracts in yogurts showed good color attention with a color difference of 7.01 plus or minus 2.36 after 12 days of storage.
