Fructose syrup from sweet potato

Fructose syrup is starch sugar crystal made by hydrolysis and isomerization of plant starch. It has unique flavor and is an important sweetener. Because its composition is mainly fructose and glucose; it is called "fructose syrup". The production of fructose syrup is not limited by regions and seasons, the equipment is relatively simple, and the investment cost is relatively low.

1, process flow: sweet potato starch--slurry--saccharification--neutralization--decolorization--filtration-resin treatment--evaporation-isomerization--decolorization--resin treatment--evaporation--finished product

2, process operation points:

① Slurry mixing: first add some water in the powder mixing barrel, add sweet potato starch under stirring, after feeding, continue to add water to make starch emulsion reach the specified concentration (40%), and then add hydrochloric acid to adjust the pH value to 18.

② saccharification: adjust starch milk, use acid pump to send water saccharification tank, after feeding, open steam valve to increase pressure to about 2.8 kg/cm2, keep this pressure for 3~5 minutes, sample, check saccharification end point with 20% iodine solution. The saccharification solution can be neutralized when it is red with iodine.

(3) Neutralization: the saccharification solution is transferred to a neutralization barrel for neutralization, quantitative waste carbon is added as a filter aid when stirring is started, and 10% sodium carbonate solution is gradually added for neutralization. When the pH value is 4.6~4.8, the discharge valve is opened, and the sugar solution is sent to a filter by a pump. The filtered clear sugar solution is cooled to 60 DEG C immediately, and the sugar solution is decolorized after cooling.

④ Decolorization: Put the clear sugar solution into the decolorization barrel, add quantitative activated carbon and mix it with the addition, decolorize and stir for no less than 5 minutes, and then send it to the filter, filter out the clear solution and store it in the storage barrel for later use.

Resin exchange: send the first decolorized filtered liquid to the ion exchange filter bed for desalination, purification and decolorization. After the sugar solution passes through the four lipid filtration beds of yang-yin-yang-yin, the pH value is adjusted to 3.8~4.2 in the sugar storage barrel.

Evaporation: After resin exchange, accurately adjust the pH of the sugar solution, pump it to the evaporation tank, and keep the vacuum above 500 mm Hg. The heating steam pressure shall not exceed 1 kg/cm2, and when the sugar concentration is about 42%~50%, the material can be discharged.

(7) Isomerization: Solid phase isomerase is loaded into a vertical heat preservation reaction column, the reaction temperature is controlled at 65 DEG C, refined sugar solution is fed from the top of the column, flows through the enzyme column, undergoes isomerization reaction, and then is discharged from the bottom of the column, continuous operation, or can be fed from the bottom of the column, flows through the enzyme column, and is discharged from the top of the column. When the enzyme activity is at the optimum pH value, the catalytic effect can be fully exerted, the reaction speed is fast, the reaction time is short, the degree of side reaction of sugar decomposition is low, and the obtained isomeric sugar solution is light in color and easy to refine. Therefore, the pH value of the sugar solution during isomerization depends on the type of isomerase used.

Secondary decolorization: After the isomerization reaction, the resulting sugar solution contains colored substances and can produce impurities such as color and ash during storage, so secondary decolorization is required. sugar solution is sent into a decoloring barrel, quantitative fresh active carbon is adde, and that operation is the same as that of the first decoloring.

Secondary resin exchange: The sugar solution after secondary decolorization needs to undergo another resin exchange, the method is the same as before. The pH value of the final effluent sugar solution is relatively high, and the pH value can be adjusted to 4.0~4.5 with hydrochloric acid.

evaporation concentration; refined sugar solution is concentrated to the required concentration by vacuum evaporation tank, and fructose syrup is obtained. Since glucose is easy to crystallize, in order to prevent crystallization of syrup during storage, the sugar solution cannot be evaporated to an excessive concentration, generally required to be between 70% and 75%(dry matter concentration).