The invention provides a method for preparing
theabrownin and low-molecular-weight tea polysaccharides by
solid state
fermentation of
green tea as a
raw material by adopting
aspergillus niger and
trametes trogii. The method comprises the following steps: inoculating, performing
solid state
fermentation, extracting, performing separation and purification,
drying and the like. Specifically, the method comprises the following concrete steps: spraying water containing
aspergillus niger and
trametes trogii into crushed
green tea, and fermenting in a room-temperature environment to obtain a fermented material; adding water into the fermented material, performing heating extraction, and filtering extraction liquid through gauze and a
microfiltration membrane to obtain filter liquor; performing heat
evaporation concentration or vacuum concentration on the filter liquor, adding an edible
alcohol aqueous solution into concentrated liquid, fully uniformly mixing, standing, centrifuging, and collecting supernatant and precipitate after
centrifugation respectively; performing heat
evaporation concentration or vacuum concentration on the supernatant, filtering through an
ultrafiltration membrane, and performing spray-
drying or vacuum freeze-
drying on filter liquor to obtain
solid powder namely
theabrownin; dissolving precipitate generated after
centrifugation by using water, and spray-drying or freeze-drying to obtain low-molecular-weight tea polysaccharides.