Monascus purpureus is known as the koji mould that makes red-colored Japanese sake. Monascus Yellow is obtained by first drying out cultures of Monascus purpureus, which is then pulverized for extraction with ethanol made mildly acidic by hydrochloric acid and subsequent neutralization. Monascus Yellow is composed mainly of xanthomonacins, which emit fluorescence. It is primarily used for coloring jelly and frozen confectionery.