Method for preparing LUO HAN GUO sweetening composition from Siraitia grosvenorii and use thereof

A method for extracting a sweetening composition from Siraitia grosvenorii, comprising:

• putting mature Siraitia grosvenorii and immature Siraitia grosvenorii together at a weight ratio of 1:4 to 1:8, sealing and holding at 25° C. to 38° C. for 2 to 4 days, then placing in a ventilated environment for 1 day to 4 days to obtain raw materials of the Siraitia grosvenorii,
• juicing the raw materials of the Siraitia grosvenorii to obtain juice and fruit residues,
• combining the juice with the extract solution obtained by extracting the fruit residues with purified water, removing impurities, and concentrating and purifying, to obtain the sweetening composition,
• wherein said removing impurities comprises:
• a) centrifuging to remove pulp tissues from the extract solution;
• b) filtering the centrifugal solution using a ceramic membrane with a pore size of 50 to 100 nm to obtain a filtrate;
• and
• c) adsorbing impurities in the filtrate using a macroporous adsorption resin chromatography column,
• wherein said c) comprises:
• 1) adsorbing substances in the filtrate that are weaker in polarity than main sweet components of Siraitia grosvenorii using a non-polar macroporous adsorption resin chromatography column or a weakly polar macroporous adsorption resin chromatography column, and starting to collect an effluent when a mogroside V is eluted;
• 2) adsorbing the impurities of polyphenols and organic acids in the effluent collected in said 1) using a polar macroporous adsorption resin chromatography column, and collecting the effluent by fractions;
• and
• 3) washing the chromatography column undergoing said 2) with purified water, collecting the water washing solution by fractions, selectively combining the water washing solution with the effluent collected in said 2), concentrating and purifying components with good taste, and discarding the components with undesirable taste,
• wherein a volume-to-mass ratio (L/kg) of the amount of resin in the non-polar macroporous adsorption resin column to the total amount of the Siraitia grosvenorii is 1:2 to 1:5, and a flow rate is 1 to 3 BV/h,
• a volume-to-mass ratio (L/kg) of the amount of resin in the polar macroporous adsorption resin column to the mogroside V in the solution loaded on the column is 50:1 to 200:1.