The invention provides a method of preparing chestnut shell
brown pigment by ultra-
micronization in cooperation with pulsed
electric field, comprising the steps of (1), cleaning, washing and
drying chestnut shells and then primarily crushing the chestnut shells; (2), adding coarse chestnut shell
powder into an ultra-
micronization apparatus for wall breaking to obtain chestnut shell superfine
powder; (3), using
ethanol solution as an extracting
solvent to extract the chestnut shell superfine
powder by the aid of a pulsed
electric field treating device, filtering, and combining double extracts to obtain
pigment extract; (4), concentrating the
pigment extract under reduced pressure to 1 / 3 of the original size, and carrying out
alcohol precipitation,
solid-liquid separation, concentration and
drying to obtain the chestnut shell
brown pigment that is powdery. The ultra-
micronization and pulsed
electric field treating techniques are combined, no heating is required to provide quick and complete
dissolution of the chestnut shell
pigment, extracting time and energy can be greatly saved, and the method has the advantages of rich material sources, low extracting temperature, high product yield is high, short
treatment time, good operational simplicity and the like; the obtained chestnut shell
brown pigment has
high color intensity, good water-
solubility, stable quality, safety with no
toxicity and is worthy of practical production and conversion and practical popularization and application.