NOVELTY - Extracting geniposide from liquid waste involves (a) recovering solid content from waste, (b) adding water and ethanol to recovered product and precipitating carbohydrate impurities, filtering precipitated product and concentrating filtrate, (c) adjusting pH of concentrated product and hydrolyzing using cellulase, (d) extracting hydrolyzed product using organic solvent, and combining extracts, (e) decolorizing extracts, and (f) concentrating extract, filtering concentrated product, adding organic solvent to product, filtering and crystallizing product and drying crystal.    USE - The method is useful for extracting geniposide directly from liquid waste obtained after production of yellow pigment from Gardenia (claimed).    ADVANTAGE - The method reduces consumption of solvent and shortens extraction time.    DETAILED DESCRIPTION - Method for extracting geniposide directly from liquid waste obtained after production of yellow pigment from Gardenia, involves (a) recovering 40-50 wt.% solid content from the waste by nanofiltration, (b) adding 2-4 volumes purified water and 90% ethanol to the recovered product and precipitating carbohydrate impurities, filtering precipitated product and concentrating filtrate containing 55-65% geniposide, (c) maintaining pH of concentrated product to 4.5-5 using citric acid and sodium citrate buffer, where the ratio of concentrated product and mixture of citric acid and sodium citrate buffer is 1 g:1-3 ml, mixing 1 g mixture with 0.3-0.8 g cellulase having activity of 10000-30000 U/g and hydrolyzing under continuous stirring condition at 30-40 degrees C for 2-4 hours, (d) extracting hydrolyzed product for 2-4 times continuously using organic solvent for 30-60 minutes, where the volume ratio of hydrolyzed product and organic solvent is 1:1-3, and combining extracts, (e) decolorizing extracts using active carbon granules to obtain clear and transparent extract, and (f) concentrating extract under reduced pressure and cooling concentrated product, filtering concentrated product, adding 2-4 volumes organic solvent to the product, filtering and crystallizing product and drying crystal at low-temperature. An INDEPENDENT CLAIM is included for method for preparing yellow pigment, which involves washing Gardenia and crushing into granules with particle size of 1-3 mm, adding 8-12 times purified water to the granules, extracting mixture with pectinase and protease at 45-55 degrees C for 2-3 times, where each time the extraction is done for 2-4 hours, and combining the extracts, washing extract using plate centrifuge or spiral centrifuge, filtering supernatant at 35-45 degrees C under pressure of 0.4-0.8 MPa using inorganic ceramic membrane filter having 0.1-0.6 mu m pore size, collecting filtrate and passing through ultrafiltration membrane having 6000-10000 Dalton molecular weight at 35-45 degrees C under pressure of 0.55-0.85 MPa, collecting filtrate and passing through sulfonated polyethersulfone nanofiltration membrane having 500-700 Dalton molecular weight at 40-50 degrees C under pressure of 1.5-2 MPa, and collecting filtrate as yellow pigment and removing liquid waste.