The extraction of anthocyanins will be performed according to Looi (2008) with modification. The shredded
roselle calyces and red cabbages were added in distilled water in different beaker. The mixtures were stirred and
heat at 35 °C on hotplate for an hour until purple color appeared. The extracted solution was poured through the
coffee filter to remove the pieces of cabbage. The procedure was replicated three times. For third time replication,
the sample was soaked and stored in refrigerator for 24 hour until all anthocyanins were almost fully extracted or the
fiber become colorless through observation. The extracted solutions (25 mL) were collected in universal bottle for
concentration determination, respectively while the least was collected in a beaker. The extracted solvents were
evaporated at 50 °C under vacuum (Looi, 2008).