PROCESS CONDITIONS AFFECT PIGMENT QUALITY AND YIELD IN EXTRACTS OF PURPLE SUNFLOWER HULLS

Extract of purple sunflower hulls is a potential red food colorant; ho wever, suitable process conditions must still be identified. Selected process variables were studied using bench-scale units to prepare, cla rify, concentrate and spray dry extracts. Concentration by evaporation at 32 degrees C and addition of maltodextrin to 15% (wt/dry wt) prior to drying largely eliminated pigment degradation during those steps. Relative to water extracts, extracts prepared with 5 to 15% ethanol in water generally yielded more pigment with similar levels of degradati on and loss during subsequent processing. Use of 5% ethanol/2% citric acid reduced yield by about half relative to water, but gave a powder with a lower degradation index and wetting time. Percentage recovery o f pigment during concentration and drying was not greatly affected by solvent type or extraction temperature.