Adopt spectrophotometry to detect the content of sodium gluconate; select spectrophotometry, detect pigment content in solution under the absorption wavelength of 670nm; adopt iodine B method to measure the content of reducing substance in solution and sodium gluconate crystalline product.
Get primary crystallization mother liquor 500g, the content of sodium gluconate is 40wt%, adopt commercially available HZ806 resin to decolorize primary crystallization mother liquor, select HZ806 resin chromatography column diameter to be 1cm, and the height-diameter ratio of HZ806 resin chromatography column is 8: 1. The flow rate of primary crystallization mother liquor through HZ806 resin chromatography column is 12BV/h; the operating temperature is room temperature.
Using commercially available HZ806 resin to decolorize the primary crystallization mother liquor includes the following steps: (a) pretreatment of the macroporous adsorption resin into a chromatography column to obtain a macroporous adsorption resin chromatography column; (b) decolorizing the primary crystallization mother liquor Diluted until the sodium gluconate content is 35% by mass; (c) carry out adsorption and decolorization treatment on the liquid treated in step (b) through a macroporous adsorption resin chromatography column to obtain an intermediate crystallization mother liquor; (d) adsorb the saturated macropores The adsorption resin is regenerated.
The average particle size of the commercially available HZ806 resin is 0.3 mm, and the water content is 50 wt %. The pretreatment method is as follows: rinsing, screening, soaking in ethanol solution for 2 hours, and placing it in a chromatographic column, at a flow rate of 3 times the bed volume per hour, and 5 times the resin volume of ethanol through the resin layer, until the effluent is diluted with water. After treatment with ethanol, deionized water was passed through the resin layer at a flow rate of 6 times the bed volume per hour to replace the ethanol.
The regeneration treatment of macroporous adsorption resin HZ806 is washing with 0.1mol/L sodium hydroxide solution, then washing with 60% ethanol solution, and finally washing with deionized water.
Using commercially available HZ806 resin to decolorize the primary crystallization mother liquor, the obtained intermediate crystallization mother liquor has a mass of 490 g, a sodium gluconate content of 40 wt%, and a pigment removal rate of 20%.
490 g of the intermediate crystallization mother liquor with a sodium gluconate content of 40 wt% was subjected to sugar removal by ion exchange resin. The use of ion exchange resin to remove sugar from the intermediate crystallization mother liquor includes the following steps: (1) loading the ion exchange resin pretreatment into a chromatography column to obtain an ion exchange resin chromatography column; (II) diluting the intermediate crystallization mother liquor to glucose The sodium content is 10wt%; (III) the liquid after the step (II) treatment is passed through the ion exchange resin chromatography column, the sodium gluconate in the intermediate crystallization mother liquor is adsorbed on the ion exchange resin, and the adsorption treatment is carried out; (IV) Desorb the ion exchange resin adsorbed with sodium gluconate to obtain purified crystallization mother liquor; (V) regenerate the ion exchange resin.
The ion exchange resin was selected from commercially available strong base type anion exchange resin D201, with an average particle size of 0.3 mm and a water content of 50 wt%. The pretreatment method of the anion exchange resin D201 is as follows: soak in deionized water for 2 hours, pour out the water, wash with deionized water until clear, add 4 times the amount of 2mol/L sodium hydroxide solution after removing the water, stir for 4 hours, remove the lye, use Wash with deionized water until neutral, add 4 times the amount of 2mol/L hydrochloric acid solution and stir for 4 hours, remove the acid solution, wash with deionized water until neutral, repeat three times, and finally convert the resin into alkaline (2mol/L) with sodium hydroxide solution. /L sodium hydroxide solution immersion), washed with deionized water until neutral.
The operating conditions for removing sugar from the intermediate crystallization mother liquor using ion exchange resin are:
The operating conditions of the adsorption treatment: the adsorption temperature is 20°C; the flow rate of the intermediate crystallization mother liquor passing through the ion exchange resin chromatography column is 5BV/h, and after the adsorption is saturated, the ion exchange resin is desorbed;
The operating conditions of the desorption treatment: the desorption solution is 0.5mol/l sodium hydroxide solution, the flow rate of the desorption solution through the ion exchange resin chromatography column is 2BV/h, and the desorption temperature is 30°C.
The regeneration treatment of the ion exchange resin is to wash with deionized water to neutrality, wash with 2 times of column volume and a sodium hydroxide solution with a concentration of 2mol/L, and then wash with deionized water to neutrality for later use.
After the desugaring purification treatment, the concentration of the purified crystallization mother liquor was diluted. In order to facilitate the material balance calculation, when it was converted into a sodium gluconate solution with a concentration of 35 wt%, the quality of the purified crystallization mother liquor was 500 g. The reducing sugar content is less than 0.5 wt%.
After mixing the above-mentioned purified crystallization mother liquor with 1000g of sodium gluconate fermentation filtrate with a sodium gluconate concentration of 40wt%, take 500g of the mixed solution with a sodium gluconate content of 38wt% and put it into a crystal with a vacuum-sealed stirring device. Evaporate and crystallize in the device, the crystallization vacuum degree is 0.08MPa, and the crystallization temperature is controlled to be 64°C to obtain 167.2g of sodium gluconate crystal product, wherein the sodium gluconate content is 98.54wt%, the total crystallization yield is 87.68%, and the product appearance is white, Good chroma and uniform particle size.
Sodium gluconate production new method, concrete steps are as follows:
(1) Adjust the concentration and pH value of the starch milk that has passed the acceptance inspection according to the process requirements, adjust the raw water to control the Baume degree of the starch milk to 16-20, pH 5.3-5.8, and add the enzyme preparation in proportion, and the dosage of the enzyme preparation is 0.5 Kg/T dry base starch, stir well, and the enzyme preparation is Aspergillus niger;
(2) enter the material obtained in step (1) into the ejector, the injection temperature is controlled at 105-115 ℃, the material is kept in the pipeline for 60-65 seconds, enters the liquefaction tank, and maintains the temperature in the liquefaction tank at 80-85 ℃ 30-35 minutes, the obtained material is liquefied liquid;
(3) Adjust the pH value of the liquefied liquid to 4.3 to 4.5; the temperature is 60 to 62 °C, add saccharification enzyme according to the weight of the dry base starch, and the amount of saccharification enzyme is 0.45Kg/T dry base starch. After sufficient hydrolysis, the DX value of the liquefied liquid is greater than ; 96%, that is, the glucose content > 96%, and the material is called saccharification solution at this time;
(4) Use the plate and frame filter press to remove the agglomerated protein in the saccharification solution, and then enter the decolorization and filtration step until the decolorization light transmittance≧99.0%, hue≦1.0, sugar degree≧31.0%, protein≦0.14% qualified ;
(5) Entering the qualified saccharification solution in step (4) into the sugar-eliminating storage tank, adding 0.3-0.4% potassium dihydrogen phosphate, 0.3-0.4% ammonium dihydrogen phosphate, 0.1-0.2 After % magnesium sulfate, spray, the spray temperature is 100-105 ℃, and the obtained sterilized saccharification solution is obtained;
(6) put the sterilized and sterilized saccharification solution of step (5) into the seed tank, insert 500-600ml strains, and firstly carry out seed culture; then insert the fermenter, ventilate fermentation, and adjust the fermentation process with NaOH pH to 4.50-5.50, residual sugar is less than 0.2g/dl, the fermentation ends, adjust the pH to 7.10-7.50 to obtain fermentation broth; enter the subsequent fine filtration section;
(7) the fermented liquid that step (6) obtains is sent to decolorization tank, start to heat up, add activated carbon when temperature is to 60 ℃, the consumption of activated carbon is 3.0% of dry matter weight in fermented liquid, temperature rises to 65 ℃, and is incubated to 30 minutes Then start filtering, and the filtrate is transported to the evaporation process;
(8) the filtrate of step (7) is put into the evaporator to carry out evaporative concentration, when the weight percentage of the discharge dry matter is 38-43%, enter the 80T crystallizer for crystallization, when the material dry matter is 63-68%, the sodium gluconate crystal occurs, and the start Measure the solid-liquid ratio, when the solid-liquid ratio of the material in the crystallizer reaches 6:4, start discharging to the separation process;
(9) the material coming out of the crystallizer in step (8) is composed of solid-phase sodium gluconate crystals and mother liquor, separated by a separator, and at a rotating speed of 220 to 240 rpm, the obtained moisture is 5-8% sodium gluconate crystals, and after separation Machine unloading operation to release;
(10) After the separator is unloaded, the sodium gluconate is sent to the fluidized bed dryer through the blanking auger, the buffer auger and the feeding auger in turn, and the hot air in the heater is sent to the dryer by a fan at the same time. The inlet air temperature of the first chamber of the fluidized bed is 90.0-110.0 °C, and when the moisture content is less than or equal to 0.5%, it enters the next screening process;
(11) After drying, the sodium gluconate product is sieved through a 16-mesh sieve, the large particles are separated from the drum screen by the baffle plate, and the uniform particles are transferred to the material packaging system through the feeding port for packaging to form a sodium gluconate product.
