Extraction and purification method for black rice anthocyanin

The invention relates to a new extraction and purification method for black rice anthocyanin, which comprises the following eight steps of coarse crushing, fine grinding, primary water extraction, secondary water extraction, macroporous resin purification, nanofiltration, prefreezing and freeze drying. The crushed and sieved black rice powder are added with water and subjected to fine grinding with colloid, digestion at a constant temperature, solid-liquid separation by a slurry and residue separator and further purified through D101 type macroporous resin. Distilled water and 55%-95% ethanol are used successively to elute, and the eluent is crude extract of anthocyanin. A nanofiltration membrane (with the molecular weight of 100-200 Da) is used to recover ethanol from crude extract which is vacuum freeze-dried to obtain the black rice anthocyanin finally. Black rice anthocyanin can be eaten directly, and also can be added into beverage, sauce products, cookies and other foods as an auxiliary material, or used in cosmetic as a colorant.