Process for manufacturing food grade colors from flowers, typically hibiscus

摘要

A process for the manufacture of food colors from hibiscus flowers comprising the steps of removing the calyx and the androceum of half bloom flowers; washing the flowers; and storing the flowers in a pre-cleaned stainless vessel; heating the flowers with water in a decoction chamber to at least 65 degrees to 70 degrees celsius; preparing a 5 percent w/v solution of an alkaline amino acid in demineralized water; adding the alkaline amino acid solution to the decoction chamber containing the flowers until the pH in the aqueous phase is 7.5 to 8; heating the mixture in the decoction chamber till the temperature of the aqueous phase exceeds boiling point and steam is generated with pressure of at least 1.2 kg/cm; continuing the heating process for 1 to 2 hours; cooling the solution in the decoction chamber to 20 degrees celsius and releasing the pressure; transferring the solution which is a colored solution so obtained from the decoction chamber to a closed stainless steel vessel; adding an acidic amino acid to make the solution mildly acidic; maintaining the acidic colored solution under nitrogen blanketting for 5 to 6 hours for maturation at 20 degrees celsius; filtering the matured extract; dissolving 15 percent w/v in a polysaccharide such as, lactose and/or maltodextrin in the filtrate; spray drying the filtered mature extract in a spray drier; and sieving the dried powder so obtained from the spray drier to obtain a food color.