Monosodium glutamate from sweet potato

The chemical name of monosodium glutamate is sodium glutamate, also known as sodium glutamate. It is an advanced condiment that can not only improve cooking flavor, but also promote appetite and help digestion. Monosodium glutamate can be produced with sweet potato starch with low production cost.

1. Technological process: preparation of starch hydrolyzed sugar-fermentation-glutamic acid extraction and neutralization-concentrated crystallization-drying sieving-finished product

2. Key points of process operation:

① preparation of starch hydrolyzed sugar: sweet potato starch was adjusted to 16 Baume degree by adding water, and the pH value was adjusted to 6.2-6.4 with sodium carbonate. The prepared liquefied enzyme was added with 5 units per gram of dry starch. Adjust the temperature of the powder to 85-90 degrees Celsius and keep it for about 20 minutes. Check with iodine solution. It turns brown-red to orange-yellow, that is, liquefaction is complete. Then set the temperature of the powder to 100 degrees Celsius and keep it for 5 minutes in order to kill the liquefied enzyme. Then reduce the temperature of the powder to 5560 degrees Celsius and adjust the pH value to 1.8with hydrochloric acid, then add saccharifying enzyme to keep warm. Check the saccharification end point with anhydrous alcohol, end the saccharification when there is no white reaction, and heat the saccharification solution to 100 degrees Celsius to kill the enzyme. The pH value of hydrolyzed sugar solution was adjusted to 4.6 ~ 4.8 with sodium carbonate. The neutralization temperature is generally about 80 degrees Celsius. Then add 0.3% active pulp, stir evenly, so that the sugar solution decolorization, decolorization time should not be less than 30 minutes. After decolorization, the sugar solution is filtered to get the hydrolyzed sugar solution.

② fermentation: the fermentation process is divided into: slope activation-secondary shaking flask seeds-secondary tank seeds-fermentation.

B9 strain was used in glutamic acid fermentation, and the bevel culture medium was composed of 0.1% glucose, 1% peptone, 0.5% beef extract, 5% salt, 2% Agar, pH7.0, and slant culture at 32 degrees Celsius for 18 hours.

The primary seed culture medium is composed of glucose 2.5%, urea 0.5%, corn pulp 3%, magnesium sulfate 0.04%, dipotassium hydrogen phosphate 0.1%, ferric sulfate 2 parts per million, manganese sulfate 2 parts per million, pH6.8~7.0. The primary seeds were cultured at 32 degrees Celsius for 12 hours.

The composition of secondary seed culture medium is: hydrolyzed sugar 2.5%, urea 0.4%, corn pulp 3%, dipotassium hydrogen phosphate 0.15%, magnesium sulfate 0.05%, manganese sulfate 2 parts per million, pH6.8~7.0. The secondary seeds were cultured at 34 degrees Celsius for 7 hours.

Fermentation tank culture medium composition is: hydrolyzed sugar 2.5%, urea 0.6%, corn pulp 0.6%, potassium dihydrogen phosphate 0.17%, potassium chloride 0.03%, magnesium sulfate 0.06%, manganese sulfate 2 parts per million, pH6.7-7.0. The culture conditions are as follows: the amount of inoculation is 1%, the culture temperature is 35-36 degrees Celsius, and the culture time is about 35 hours.

③ glutamate extraction: most factories extract glutamate by isoelectric point method. When the pH value of the fermentation broth was adjusted to 3.22, glutamic acid was supersaturated and crystallized.

④ neutralization and decolorization: sodium glutamate is neutralized with glutamic acid and sodium carbonate to produce sodium glutamate. The neutralization temperature is 60-65 degrees Celsius, the concentration of the neutralization solution is 22 Baume degrees, and the pH value is 6.9-7.0. 106 grams of sodium carbonate can neutralize 294 grams of glutamic acid. After neutralization, the neutralization solution should be decolorized. First adjust the neutralization solution to pH6.3 with glutamic acid, heat to 60 degrees Celsius, fully dissolve sodium glutamate, add powdered activated carbon for decolorization, stir for 30 minutes, then let it naturally precipitate or filter.

⑤ concentration and crystallization: put the decolorization solution into a vacuum concentration pot, keep the vacuum above 60 mm Hg and control the temperature below 60 degrees Celsius. When the liquid concentration in the pot reaches 32 Baume degrees, the mixer is turned on, the steam is turned off, the crystal seed is inhaled in vacuum, and then the crystal liquid is centrifuged and separated in the centrifuge.

⑥ drying and sieving: dry the crystalline monosodium glutamate at 80 degrees Celsius, and then pass through the sieves of 8, 12, 20, 30 mesh, of which 12, 20, 30 mesh can be used as the finished product 99 °monosodium glutamate. Large pieces can be broken into powder and mixed with salt as powdered monosodium glutamate. Used as a small crystalline monosodium glutamate or as a seed.