The invention discloses a method for preparing a food
browning inhibitor from cedar pine needles. The method is characterized by comprising the following steps: smashing dried cedar pine needles, adding normal
hexane according to the material-to-
liquid ratio of 1g: (10-20mL), vibrating at
room temperature for 12-24h and filtering to separate a normal
hexane extracting liquid; recovering the degreased pine needles, adding 50-70wt%
methanol as an extracting agent according to the material-to-
liquid ratio of 1g: (10-30mL), vibrating at
room temperature for 24-48h, separating a supernatant, concentrating and
drying the supernatant to obtain a
methanol extract with the yield of 15-22%; suspending the
methanol extract into 20-30mL of 50wt% methanol, carrying out
chromatography by using a macroporous adsorption resin DiaionHP-20
chromatographic column, carrying out
gradient elution at the flow speed of 3-5mL / min by using water and methanol with the concentrations being respectively 0wt%, 15wt%, 30wt%, 40wt%, 60wt% and 100wt%, collecting the 40wt% methanol eluant, concentrating and
drying to obtain the food
browning inhibitor, separating and purifying by using a
high performance liquid chromatography; and obtaining the effective component, i.e., 2R, 3R-dihydromyricetin of the food
browning inhibitor.