1993 Volume 40 Issue 10 Pages 697-701
Powdered natural derived colorants, such as beet red, red cabbage, cochineal extract, carthamus yellow, gardenia yellow, kaoliang, annatto and spirulina colors, inoculated with 3×10 4 counts/g of Bacillus subtilis were irradiated with an electron beams at doses of 2.5kGy to 40kGy. All the colorants were sterilized completely by 10kGy of irradiation. Influences of irradiation on colorants were examined by measuring color tones, color values and visible absorption curves and HPLC analysis. Slight color tone changes and decolorizations by irradiation were detected but they were smaller than those by sterilization with heat. Electron beam irradiation was a practical technique for sterilizing powdered food colorants, which is easy and results in high level of sterility without any adverse effect on the color tone.
