The Structure and Photodecomposition of Monascus Pigments

Recently, some problems are pointed out by many investigators in using the synthetic dyes. In this paper, we were interested in a few natural dyes, occurred from Asp. monascus anka H-26 and determined the structure and considered the photodecomposition of these dyes. One of these dyes was identified with an ankaflavin and another was seemed to be a monascamine. It was also added an edible pigment for practical uses, photodecomposition of one of these dyes was pursued further. In order to depress the photodecomposition, some nutritional antioxidants, vitamin C, vitamin E and meranoidines, derived from sugars and amino acids, were used. The photodecomposition of dye in aqueous solution was shown to be inhibited by the presence of vitamin C, vitamin E and meranoidine, the effectiveness of which decreased in the following order: V. C>V. C+meranoidine>V. C+V. E>V. C +V. E +meranoidine> V. E≈meranoidine≈V. E+meranoidine≈control (dye only). When this dye is used, many factors should be considered in the system of inhibitors of photodecomposition. To inhibit this dye from photodecomposition in the food materials, addition of the V. C is desirable.