The invention discloses a preparation method and a preparation control method of a
mulberry leaf extract. The preparation method comprises the steps of
cutting mulberry leaves into shreds, adding water, decocting and extracting for two times, combining two decoction-filtering liquors, filtering through a
sieve, enabling a primary filtrate to pass through a
microfiltration membrane with the bore
diameter of 0.01 to 0.02 micron, enabling a refined filtrate to pass through a
reverse osmosis membrane with the bore
diameter of 0.0001 to 0.001 micron, concentrating until a
solid content is 15 to 18 percent, performing vacuum concentration on a concentrated initial solution under 60 DEG C, to form an extractum with the
relative density of 1.10 to 1.13, and spray-
drying the extractum to obtain the
mulberry leaf extract. A
quality control method is characterized by adopting high efficiency liquid
chromatography to measure the content of
rutin in the
mulberry leaf extract. The preparation method can avoid
rutin content loss caused by washing a mulberry leaf medicinal material and performing high temperature concentration, the
rutin in the mulberry leaves is well extracted and reserved, microorganisms such as
bacteria can be well removed, and a
microorganism indicator is enabled to meet
national health food material regulations; the
quality control method is accurate, reliable and good in
repeatability, and can be taken as a method for measuring the content of the mulberry leaf extract rutin.