RU2379903C1 - Preparation method of galactooligosaccharide concentrates (versions) - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention relates to technology of the functional food products and can be used to produce galactooligosaccharide concentrate on the basis of lactose solution and lactoserum permeate. Production method of galactooligosaccharide concentrate out of lactose solution involves preparing water with pH 6.5 ± 0.5 by means of electric activation, dissolving lactose in the water, adding yeast or bacterial β-galactosidase into the lactose solution, fermenting, condensing, inactivating the ferment and cooling the obtained concentrate. The dry solids weight ratio in the mother solution is 22 ± 2%, fermentation temperature is 41 ± 2.5°C and the fermentation duration is 2.5 ± 0.5 hours. Alternatively, galactooligosaccharide concentrate is obtained out of lactoserum permeate. The fermentation temperature is 50 ± 2°C and the duration is 1.5 ± 0.5 hours. Invention enables to produce food products with high galactooligosaccharide content.

EFFECT: reduced cost of the product as well as environmentally safe production.

2 cl, 4 ex

Description

The invention relates to the technology of functional food products and can be used to obtain a concentrate of galactooligosaccharides based on a solution of milk sugar and permeate (ultrafiltrate) whey.

A known method of producing galactooligosaccharides in condensed milk whey of various types (TU 922930-007-02069473-99), which includes the following operations: separation of fat and casein dust, boiling whey proteins at a temperature of 90-95 ° C with a holding time of at least 5 minutes; thickening to a mass fraction of solids of 60-65%; serum fermentation with β-galactosidase Kluyveromyces lactis; enzyme inactivation by exposure at 95 ° C for 5 minutes; cooling to 6-8 ° C; packing. The disadvantage of this method is the low yield of oligosaccharides and the need to use acids and alkalis to achieve the optimal pH level before fermentation, which leads to additional mineralization of the finished product.

In the United States a patented method for producing galactooligosaccharides in concentrated lactose solutions using fungal β-galactosidase at high temperature (US Patent No. 4957860). The method involves preparing a 70-80% lactose solution to a boiling bath, cooling it to 62-75 ° C, introducing β-galactosidase from Aspergillus oryzae, fermentation for 4 hours, inactivation of the enzyme at 90 ° C for 20 minutes. The disadvantages of this method include the need to adjust the pH to low values, a large consumption of lactose for the preparation of the solution and additional energy consumption during fermentation.

Closest to the proposed is a method for producing syrup of galactooligosaccharides (RF Patent No. 2155232), which provides for the preparation of an aqueous solution of lactose with a concentration of 40-70% at 100-108 ° C, the introduction of a mineral acid, for example hydrochloric, in an amount of 0.01-0.12 g / mol per 1 kg of lactose solution, keeping the resulting mixture for 20-120 minutes at the indicated temperature to form galactooligosaccharides, cooling the syrup and neutralizing it with an alkaline agent until a pH of 4.5-6.5 is reached. This method provides a high yield of galactooligosaccharides, however, it requires the use of concentrated acids and high temperature for its implementation.

The advantage of the proposed method compared to the prototype is the use of the enzyme preparation β-galactosidase for the synthesis of galactooligosaccharides, which eliminates the formation of reaction by-products and the oxidation of carbohydrates present in the reaction mixture. The technical result is the exclusion of the use of mineral acids for the synthesis of galactooligosaccharides, due to the use of the reagentless method of regulating the pH of the solution. By using this method, the cost of the product is reduced (since the use of additional reagents, acids and alkalis, to regulate the pH is excluded, in addition, there is no need for demineralization of the finished product), as well as the environmental safety of production. The necessary technical result is achieved as follows: pH regulation is carried out by electrochemical activation to a value optimal for the manifestation of β-galactosidase transgalactosylating activity.

The method is as follows.

When using a lactose solution as raw material, refined or food sugar is dissolved in electroactivated water with a pH value of 6.5 ± 0.5 to obtain a solution of 22 ± 2% concentration. Next, a yeast or bacterial β-galactosidase preparation is introduced into the homogeneous solution. Fermentation is carried out under the following conditions: temperature 41 ± 2.5 ° C, pH 6.5 ± 0.5, the dose of the enzyme is 2 liters per 1 ton of solution, duration 2.5 ± 0.5 hours. After fermentation, the solution containing galactooligosaccharides, thicken to a mass fraction of solids of 60%. To inactivate the enzyme at the end of thickening, the temperature is raised to 70 ° C. Next, the concentrate is cooled and packaged.

The method using whey permeate as a raw material includes the following operations: receiving whey, heating it to 40 ° С and separation, ultrafiltration, collecting permeate, thickening it to a solids content of 22 ± 2%, electroactivation of permeate to pH 6.5 ± 0.5, application of a yeast or bacterial β-galactosidase preparation, fermentation at a temperature of 50 ± 2 ° C for 1.5 ± 0.5 hours. After fermentation, the sequence of operations is the same as in the production of a concentrate from a lactose solution.

The solids content in the initial solution is set at 22 ± 2%, since in the case of permeate, a more concentrated solution causes difficulties in the electroactivation process, and in the case of a lactose solution at a temperature of 41 ± 2.5 ° C, a homogeneous solution of a higher concentration is impossible. With a lower solids content in the solution, the process is impractical, because at low concentrations of lactose, the enzyme β-galactosidase exhibits predominantly hydrolytic activity, and galactooligosaccharides are formed in smaller quantities. The choice of process temperature is due to the fact that lower temperatures do not allow to obtain a homogeneous lactose solution of the required concentration, higher temperatures lead to thermal inactivation of the enzyme. It has been experimentally established that both an increase and a decrease in the pH level leads to a decrease in the transgalactosylating activity of the enzyme, and therefore, the yield of galactooligosaccharides. The choice of the duration of the process is due to the fact that with a shorter thermostating time, the enzyme does not show sufficient activity, and with an increase in the exposure time, β-galactosidase activity shifts toward the formation of lactose hydrolysis products, therefore, the output of galactooligosaccharides decreases.

Example 1. Carry out the electroactivation of water to a pH of anolyte 6.0, heat it to 80-85 ° C. Take 220 g of milk sugar and prepare 1 l of a solution of lactose in electroactivated water. The solution is cooled to 38.5 ° C and 2 ml of yeast or bacterial β-galactosidase preparation are added. The mixture is thermostated at 38.5 ° C for 2.5 hours. After fermentation, the solution containing galactooligosaccharides is concentrated to a mass fraction of solids of 60%. To inactivate the enzyme at the end of thickening, the temperature is raised to 70 ° C. The degree of conversion of lactose in this case is 55%.

Example 2. The electroactivation of water is carried out to a pH value of anolyte 7.0, it is heated to 80-85 ° C. Take 220 g of milk sugar and prepare 1 l of a solution of lactose in electroactivated water. The solution is cooled to 43.5 ° C. and 2 ml of yeast or bacterial β-galactosidase preparation are added. The mixture is thermostated at 43.5 ° C for 2.5 hours. After fermentation, the solution containing galactooligosaccharides is concentrated to a mass fraction of solids of 60%. To inactivate the enzyme at the end of thickening, the temperature is raised to 70 ° C. The degree of conversion of lactose in this case is 82%.

Example 3. Whey is taken by weight and quality. Serum must be degreased and casein dust separated by separation. Ultrafiltration is carried out at 55 ° C, the resulting permeate is concentrated in a vacuum evaporator at a temperature of 55-60 ° C to a mass fraction of solids of 20%. The permeate is treated in an electroactivation unit to obtain an acid fraction with a pH value of 6.0. Fermentation is carried out with a yeast or bacterial β-galactosidase preparation at 48 ° C for 90 minutes. After fermentation, the mixture is concentrated to a mass fraction of solids of 60%; to inactivate the enzyme at the end of concentration, the temperature is raised to 70 ° C. The degree of conversion of lactose in this case is 51%.

Example 4. Whey is taken by weight and quality. Serum must be degreased and casein dust separated by separation. Ultrafiltration is carried out at 55 ° C, the resulting permeate is concentrated in a vacuum evaporator at a temperature of 55-60 ° C to a mass fraction of solids of 20%. Permeate is treated in an electroactivation unit to obtain an acid fraction with a pH value of 7.0. Fermentation is carried out with a yeast or bacterial β-galactosidase preparation at 52 ° C for 90 minutes. After fermentation, the mixture is concentrated to a mass fraction of solids of 60%; to inactivate the enzyme at the end of concentration, the temperature is raised to 70 ° C. The degree of conversion of lactose in this case is 80%.

Claims (2)

1. A method of obtaining a concentrate of galactooligosaccharides from a lactose solution, comprising preparing water with an optimal pH, dissolving lactose in it, introducing a yeast or bacterial β-galactosidase preparation, fermenting under optimal conditions, thickening, inactivating the enzyme, cooling the syrup, characterized in that for the preparation of water with an optimal pH value uses the electroactivation method, while the process parameters are as follows: mass fraction of solids in the initial lactose solution 22 ± 2%, water pH 6.5 ± 0.5, temperature 41 ± 2.5 ° С, fermentation duration 2.5 ± 0.5 hours 2. A method of producing a concentrate of galactooligosaccharides from whey permeate, comprising condensing the permeate, setting the optimum pH, introducing a yeast or bacterial β-galactosidase preparation, fermenting under optimal conditions, thickening, inactivating the enzyme, cooling the syrup, characterized in that establishing the optimal pH carried out by the method of electroactivation, while the process parameters are as follows: mass fraction of solids in condensed permeate 22 ± 2%, permeate pH 6.5 ± 0.5, temperature 50 ± 2 ° C, about olzhitelnost fermentation 1.5 ± 0.5 h.