Abstract: The invention provides a D-psicose crystal and a preparation method thereof. The method comprises: adding a seed crystal to a D-psicose solution and stirring uniformly, subjecting the solution to crystallization by gradient cooling and constant-temperature crystallization alternately at 50-30° C., stopping the crystallization until the temperature of the solution is 30° C., separating the crystal by centrifugation, washing and drying, to obtain a D-psicose crystal. Rather than evaporative crystallization, organic solvent-assisted crystallization and ultrasonication, controllable crystallization by gradient cooling, constant-temperature crystallization, and other technical means are employed. Thus, the invention has low requirements for equipment, simple process, low energy consumption, and low preparation cost, and thus particularly suitable for large-scale industrial production and processing. The purity of the D-psicose crystal obtained is ?98.

Abstract: A method of preparing paprika red pigment with low polycyclic aromatic hydrocarbons includes (1) drying, crushing and granulating mature peppers to obtain pepper particles; (2) extracting the pepper particles with a vegetable oil in a rotocel extractor to obtain a paprika red pigment solution; (3) extracting the paprika red pigment solution with an ethanol solution in a liquid-liquid extractor to remove spicy substances; (4) running the paprika red pigment solution through a low-pressure chromatography column to remove polycyclic aromatic hydrocarbons; and (5) concentrating the paprika red pigment solution to obtain the paprika red pigment with low polycyclic aromatic hydrocarbons.

Abstract: A method of preparing a flavor composition containing D-allulose includes: (1) weighing D-allulose, mogroside, steviol glycoside and trichlorosucrose in parts by weight, and mixing them evenly to obtain a mixed powder; (2) degassing, compressing, and rolling the mixed powder, and extruding the raw materials into flakes; and (3) crushing and granulating the shaped flakes to obtain the flavor composition. D-allulose is used as the main raw material, and added high-intensity sweeteners as auxiliary raw materials. After the raw materials are mixed evenly, dry granulation is adopted, and the powder is degassed and pre-compressed by using the crystal water in the raw materials, and squeezed by a hydraulic roller to form a bonding force between the various sweetener molecules to form flakes, and the flakes are processed by processes such as crushing and granulating to obtain the flavor composition granules containing D-allulose with the various sweeteners integrated uniformly as a whole.

Abstract: The invention discloses a gardenia blue pigment with high brightness and low redness and a preparation method therefor, and belongs to the technical field of pigment extraction. Genipin, an enzymolysis product of gardenia extract, is used as a raw material. Genipin and amino acids (phenylalanine, tryptophan, glycine, or tyrosine) are weighed at a molar ratio of 1:(0.375-0.75), and subjected to a polymerization reaction under a conventional condition to generate a gardenia blue precursor. The gardenia blue precursor is oxidized to develop a color, refined by using ultrafiltration membrane, and finally spray-dried to obtain the gardenia blue pigment with high brightness, low redness, and low cost.

Abstract: A method of preparing water-soluble lutein ester microcapsules includes: mixing marigold flower particles with an extracting solvent, refluxing at 65-85° C.; removing the extracting solvent to obtain a crude extract; washing the crude extract with a washing solvent; removing the washing solvent to obtain a crude lutein ester; adding an oil-phase antioxidant and a vegetable oil to the crude lutein ester, mixing and heating at 90-100° C. to obtain a lutein ester oil phase; adding a wall material, an emulsifier, a water-phase antioxidant, and a water-phase filler into water, and heating to obtain a water phase; adding the lutein ester oil phase to the water phase under a high-speed shearing, mixing evenly, and homogenizing to obtain a lutein ester emulsion; drying twice to obtain semi-finished lutein ester microcapsules; and solidifying to obtain the lutein ester microcapsules. Water-soluble lutein ester microcapsules prepared by the method are also disclosed.

Abstract: The present invention relates to the technical field of microbial fermentation engineering, and specifically to a method for producing psicose 3-epimerase by high-density fermentation. In view of the low expression level of psicose 3-epimerase and other problems existing in the current fermentation, by controlling the feeding rate in the fermentation process, improving the culture temperature in the middle and late stages of fermentation and other measures in the present invention, the OD value during the fermentation with recombinant Bacillus subtilis and the total enzyme activity of psicose 3-epimerase in the fermentation broth are significantly increased, the expression of psicose 3-epimerase is markedly improved, and the production cost of allulose is reduced. Therefore, the present invention has a very broad prospect of application in industry.

Abstract: The invention provides a D-psicose crystal and a preparation method thereof. The method comprises: adding a seed crystal to a D-psicose solution and stirring uniformly, subjecting the solution to crystallization by gradient cooling and constant-temperature crystallization alternately at 50-30° C., stopping the crystallization until the temperature of the solution is 30° C., separating the crystal by centrifugation, washing and drying, to obtain a D-psicose crystal. Rather than evaporative crystallization, organic solvent-assisted crystallization and ultrasonication, controllable crystallization by gradient cooling, constant-temperature crystallization, and other technical means are employed. Thus, the invention has low requirements for equipment, simple process, low energy consumption, and low preparation cost, and thus particularly suitable for large-scale industrial production and processing. The purity of the D-psicose crystal obtained is ?98.

Abstract: A method of preparing a Senna obtusifolia seed extract rich in anthraquinones and a galactomannan extract includes the following steps: (1) crushing Senna obtusifolia seeds into a Senna obtusifolia seed powder; (2) extracting the Senna obtusifolia seed powder with 40-85% ethanol, filtering to obtain an extract solution and a residue; (3) concentrating the extract solution under vacuum to obtain a concentrated extract solution, spray-drying the concentrated extract solution to obtain the Senna obtusifolia seed extract; (4) extracting the residue with membrane filtered water, conducting a centrifugation to obtain a supernatant; (5) adding ammonium sulfate and ethanol to the supernatant to form a two-phase aqueous system, collecting a bottom layer of the two-phase aqueous system; and (6) conducting an ultrafiltration of the bottom layer with a cut-off molecular weight of 50 k-200 k to obtain a galactomannan extract solution, drying the galactomannan extract solution under vacuum to obtain the galactomannan extra

Abstract: A method for preparing a water-soluble curcumin mixture with high bioavailability includes the following steps: A) dissolving curcumin, vitamin C and ascorbyl palmitate in an ethanol aqueous solution, evaporating ethanol under reduced pressure, and vacuum drying to obtain a curcumin-vitamin C-ascorbyl palmitate co-crystal; B) high-speed emulsifying the curcumin-vitamin C-ascorbyl palmitate co-crystal and a wall material colloidal solution under vacuum, sequentially conducting a two-stage wet grinding, a homogenization and a potential adjustment to obtain an emulsified body; and C) subjecting the emulsified body to microencapsulation with a wall material twice and drying to obtain the water-soluble curcumin.

Abstract: A method for preparing a Hovenia dulcis Thunb extract rich in dihydromyricetin includes the following steps: (1) crushing Hovenia dulcis Thunb seeds to obtain a Hovenia dulcis Thunb powder; (2) adding a 10-95% ethanol solution in an amount of 3-15 times of an amount of the Hovenia dulcis Thunb powder, stirring and extracting at 20° C.-80° C. twice; (3) filtering to obtain an extract solution; (4) concentrating the extract solution by evaporating ethanol under reduced pressure to obtain a crude extract, the crude extract having a solid content of 10%-40%; (5) placing the crude extract at ?20° C. to 8° C. for 0.5 to 12 hours; (6) centrifuging the crude extract to obtain a supernatant; and (7) spray-drying the supernatant to obtain the Hovenia dulcis Thunb extract.

Abstract: A method for preparing a water-soluble curcumin liquid includes the following steps: A) dissolving curcumin, vitamin C and ascorbyl palmitate in an ethanol aqueous solution, evaporating ethanol under reduced pressure, and vacuum drying to obtain a curcumin-vitamin C-ascorbyl palmitate co-crystal; and B) high-speed emulsifying the curcumin-vitamin C-ascorbyl palmitate co-crystal and a water-soluble colloidal solution that includes an emulsifying additive under vacuum, sequentially conducting a two-stage wet grinding, a homogenization and a potential adjustment to obtain the water-soluble curcumin liquid.

Abstract: A method for preparing a water-soluble curcumin mixture with high bioavailability includes the following steps: A) dissolving curcumin, vitamin C and ascorbyl palmitate in an ethanol aqueous solution, evaporating ethanol under reduced pressure, and vacuum drying to obtain a curcumin-vitamin C-ascorbyl palmitate co-crystal; B) high-speed emulsifying the curcumin-vitamin C-ascorbyl palmitate co-crystal and a wall material colloidal solution under vacuum, sequentially conducting a two-stage wet grinding, a homogenization and a potential adjustment to obtain an emulsified body; and C) subjecting the emulsified body to microencapsulation with a wall material twice and drying to obtain the water-soluble curcumin.

Abstract: A method of preparing a Pueraria flower extract rich in isoflavones includes: grinding dry Pueraria flowers to obtain a Pueraria flower powder; adding a first 20-50% ethanol solution to form a mixture, stirring and heating the mixture at 20-80° C. for 1-4 hours, removing the first solution, adding a second 20-50% ethanol solution, stirring and heating the mixture, removing the second solution, and combining the first solution and the second solution to obtain an extract solution; filtering the extract solution to remove solids; concentrating the extract solution under vacuum to obtain a crude extract containing 10-40% solid components; adding anhydrous ethanol solution to reach an ethanol concentration of the crude extract of 75-95%, storing the crude extract at 20-30° C. for 1-4 hours; centrifuging the crude extract at a speed of 2,000-5,000 r/min to obtain a supernatant; and concentrating and spray drying to obtain the Pueraria flower extract without any purification steps.

Abstract: A method of preparing a Senna obtusifolia seed extract rich in anthraquinones and a galactomannan extract includes the following steps: (1) crushing Senna obtusifolia seeds into a Senna obtusifolia seed powder; (2) extracting the Senna obtusifolia seed powder with 40-85% ethanol, filtering to obtain an extract solution and a residue; (3) concentrating the extract solution under vacuum to obtain a concentrated extract solution, spray-drying the concentrated extract solution to obtain the Senna obtusifolia seed extract; (4) extracting the residue with membrane filtered water, conducting a centrifugation to obtain a supernatant; (5) adding ammonium sulfate and ethanol to the supernatant to form a two-phase aqueous system, collecting a bottom layer of the two-phase aqueous system; and (6) conducting an ultrafiltration of the bottom layer with a cut-off molecular weight of 50 k-200 k to obtain a galactomannan extract solution, drying the galactomannan extract solution under vacuum to obtain the galactomannan extra

Abstract: A method for preparing a Hovenia dulcis Thunb extract rich in dihydromyricetin includes the following steps: (1) crushing Hovenia dulcis Thunb seeds to obtain a Hovenia dulcis Thunb powder; (2) adding a 10-95% ethanol solution in an amount of 3-15 times of an amount of the Hovenia dulcis Thunb powder, stirring and extracting at 20° C-80° C. twice; (3) filtering to obtain an extract solution; (4) concentrating the extract solution by evaporating ethanol under reduced pressure to obtain a crude extract, the crude extract having a solid content of 10%-40%; (5) placing the crude extract at ?20° C. to 8° C. for 0.5 to 12 hours; (6) centrifuging the crude extract to obtain a supernatant; and (7) spray-drying the supernatant to obtain the Hovenia dulcis Thunb extract.

Abstract: A method of preparing water-soluble lutein ester microcapsules includes: mixing marigold flower particles with an extracting solvent, refluxing at 65-85° C.; removing the extracting solvent to obtain a crude extract; washing the crude extract with a washing solvent; removing the washing solvent to obtain a crude lutein ester; adding an oil-phase antioxidant and a vegetable oil to the crude lutein ester, mixing and heating at 90-100° C. to obtain a lutein ester oil phase; adding a wall material, an emulsifier, a water-phase antioxidant, and a water-phase filler into water, and heating to obtain a water phase; adding the lutein ester oil phase to the water phase under a high-speed shearing, mixing evenly, and homogenizing to obtain a lutein ester emulsion; drying twice to obtain semi-finished lutein ester microcapsules; and solidifying to obtain the lutein ester microcapsules. Water-soluble lutein ester microcapsules prepared by the method are also disclosed.

Abstract: A method of preparing a Pueraria flower extract rich in isoflavones includes: grinding dry Pueraria flowers to obtain a Pueraria flower powder; adding a first 20-50% ethanol solution to form a mixture, stirring and heating the mixture at 20-80° C. for 1-4 hours, removing the first solution, adding a second 20-50% ethanol solution, stirring and heating the mixture, removing the second solution, and combining the first solution and the second solution to obtain an extract solution; filtering the extract solution to remove solids; concentrating the extract solution under vacuum to obtain a crude extract containing 10-40% solid components; adding anhydrous ethanol solution to reach an ethanol concentration of the crude extract of 75-95%, storing the crude extract at 20-30° C. for 1-4 hours; centrifuging the crude extract at a speed of 2,000-5,000 r/min to obtain a supernatant; and concentrating and spray drying to obtain the Pueraria flower extract without any purification steps.

Abstract: A method of preparing paprika red pigment with low polycyclic aromatic hydrocarbons includes (1) drying, crushing and granulating mature peppers to obtain pepper particles; (2) extracting the pepper particles with a vegetable oil in a rotocel extractor to obtain a paprika red pigment solution; (3) extracting the paprika red pigment solution with an ethanol solution in a liquid-liquid extractor to remove spicy substances; (4) running the paprika red pigment solution through a low-pressure chromatography column to remove polycyclic aromatic hydrocarbons; and (5) concentrating the paprika red pigment solution to obtain the paprika red pigment with low polycyclic aromatic hydrocarbons.

Abstract: The invention relates to a method for the determination of crocetin and its derivative amounts and the derivative composition from gardenia yellow. The method mainly comprises of following steps: the absorbance measurement of a gardenia yellow aqueous solution at known concentration by UV-VIS, the absorption coefficient measurement of total crocetin derivative, the total crocetin derivative amount calculation according to Lambert-Beer law, the relative amount calculation of each crocetin derivative from its absorption coefficient and peak area on HPLC, the amount calculation of each crocetin derivative from the total amount of crocetin derivative and the relative amount of each crocetin derivative, and finally total crocetin amount calculation.

Abstract: The invention relates to a method for the determination of crocetin and its derivative amounts and the derivative composition from gardenia yellow. The method mainly comprises of following steps: the absorbance measurement of a gardenia yellow aqueous solution at known concentration by UV-VIS, the absorption coefficient measurement of total crocetin derivative, the total crocetin derivative amount calculation according to Lambert-Beer law, the relative amount calculation of each crocetin derivative from its absorption coefficient and peak area on HPLC, the amount calculation of each crocetin derivative from the total amount of crocetin derivative and the relative amount of each crocetin derivative, and finally total crocetin amount calculation.