SU1145977A1 - Method of preparing restored milk for mechanical and heat treatment - Google Patents

Abstract

A METHOD FOR PREPARING RESTORED MILK FOR MECHANICAL AND HEAT TREATMENT, which involves dissolving powdered milk in water, characterized in that, in order to accelerate the achievement of the physicochemical properties of the natural milk, after dissolving it, it is subjected to vacuum treatment at a pressure of 0.4-ld-37 , 5-10Pa for 10-180 s, depending on the temperature of the milk and the solids content in it. ®

Description

7050

four

sd with |

7O20

60 to 780 t, min Phage.1

This invention relates to the dairy industry, namely the production of reconstituted milk.

A known method of preparing reconstituted milk for mechanical heat treatment involves dissolving powdered milk in water, cooling to b-8 ° C, keeping the milk at this temperature for at least 3-4 hours in order to swell the proteins as much as possible, eliminate watery taste, and achieving normal density and viscosity, heating, cleaning, homogenizing, pasteurizing, cooling and bottling 1.

The disadvantage of the method lies in the fact that after dissolving the milk is kept for at least 3-4 hours, which entails large energy costs for cooling and heating the milk, the process is lengthy and requires considerable space for storage tanks for the product.

The aim of the invention is to accelerate the achievement of restored physicochemical properties of natural milk.

The goal is achieved by the fact that according to the method of dissolving dry milk in water, after dissolving, it is subjected to vacuum treatment at a pressure of 0.4-10-37.5-UPa for 10-180 seconds, depending on the milk temperature and dry matter content. in him.

FIG. Figure 1 shows the dependence of the density of reconstituted milk (dry matter content 24%) on the time it was kept in an open tank after dissolving dry milk (the density changes within 3 hours); ya fig. 2 — viscosity change from the soak time of reconstituted milk (36% dry matter); in fig. 3 interconnection of pressure and temperature at which milk boils; in fig. 4 is a scheme implementing the method.

Vacuuming. The recovered milk according to the proposed regimes allows accelerating the attainment of the restored milk with the properties inherent in the natural product, i.e. achieve appropriate gas, density and viscosity values.

Within 30 minutes after the dissolution of dried milk, the viscosity increases due to the hydration of the dispersed phase of milk protein and protein shells of fat globules (Fig. 2). In this case, the volume fraction of the dispersed phase increases, which leads to an increase in viscosity. This fact follows from Enshtein’s equation.

ju-A (, 5t (),

where ju, ju, are the viscosity of the dispersed system and the dispersion medium, respectively. Pa s; V is the volume fraction of the dispersed phase.

After the viscosity increases (Fig. 2), its decrease occurs due to the removal of gases from the milk, which are contained in it in the form of bubbles. In this case, gas bubbles form an additional part of the dispersed phase and affect the viscosity of the milk. Therefore, when gases are removed, the content of the dispersed phase in milk is reduced, as a result of which its viscosity decreases.

 Thus, before the mechanical and

heat treatment must be removed

from milk, gases to speed up the production of

constant its physicochemical properties.

The reconstituted milk should be vacuumed at different pressures, depending on its temperature and dry matter content.

The temperature of the water during the recovery of milk can vary from 10 to 70 ° C, at which there is no brewing of lumps of powdered milk yet when it is dissolved.

The solids content in the reconstituted milk should be maintained in the range (12–36%). The production of reconstituted milk with a solids concentration of more than 12% is dictated in some cases by the need for production and an increase in the efficiency of the equipment for mechanical and heat treatment.

0 The most intensive removal of gases from milk occurs when it boils under vacuum (Fig. 3).

It is established that the content of gases in natural drinking milk is

0.2 vol.%. Therefore, after evacuating reconstituted milk, it is required to achieve an appropriate gas content in it.

The results of the experiments are presented in the Q values in Table. 1 show that the corresponding gas content is reached in reconstituted milk with a solids content of 12% with a vacuum duration of 10 s, in milk with a solids content of 24% with a vacuum duration of 60 s. And in milk with a solids content of 36% with an evacuation time of 180 s. Vacuuming modes, i.e. temperature and pressure, selected according to

The process of preparing reconstituted milk for mechanical and heat treatment is carried out as follows.

Dissolving milk with specified solids concentration (12.24 and 36%)

5 from the dissolving apparatus 1 enters the hydrocyclone 2. The milk flow is regulated by the tap 3. The hydrocyclone creates the required vacuum using a vacuum pump 4. The vacuum in the hydro cyclone is monitored by a pressure gauge 5 and adjusted by the tap 6 by depressurizing the atmosphere. In a hydrocyclone, recoverable milk under vacuum conditions boils, excess air evolves from it, and with the help of a vacuum pump it discharges into the atmosphere. The residence time of the product in the hydrocyclone is controlled by varying the flow rate of the product entering it and the flow rate of the product exiting the hydrocyclone by means of the crane 7. The evacuated reconstituted milk is removed from the hydrocyclone by the centrifugal pump 8 and fed to mechanical and heat treatment. Example 1. A product with a solids content of 12% and a temperature of 10 ° C was obtained on an apparatus for dissolving dry milk. The reconstituted milk was continuously supplied to the hydrocyclone, in which the pressure was maintained at 0.8-10 Pa. The vacuum treatment time was maintained by controlling the flow rate of the product for 10 s. At the exit from the hydrocyclone, a sample was taken of the product and the gas content in the milk, density and viscosity were determined and compared with the corresponding indicators of natural milk. The gas content in milk after evacuation was 0.8–0.21%, the density at 20 ° C was 1028 kg / m, and the viscosity was 1.7710 Pa s. The values of these parameters correspond to the values for whole natural milk. Example 2. A product with a solids content of 12% and a temperature of 40 ° C was obtained in a milk dissolution unit. The reconstituted milk was continuously supplied to the hydrocyclone, in which the pressure of the PUPA was maintained. The vacuum treatment time was 10 s. Milk with a gas content of 0.2%, a density of 1027 kg / m, and a viscosity of 1.76-10Pa-c was obtained at the outlet of the hydrocyclone. The values of these parameters correspond to the values for whole natural milk. Example 3. A product with a solids content of 12% and a temperature of 70 ° C was obtained at a milk dissolution unit. The reconstituted milk was fed into the hydro clone, in which the pressure was maintained at 37-10 Pa.s. The vacuum treatment time was 10 s. At the exit from the hydrocyclone, milk was obtained with a gas content of 0.18%, a density of 1027 kg / m, and a viscosity of 1.76 BNa.s. The values of these parameters correspond to the values for whole natural milk. Example 4. A product with a solids content of 24% and a temperature of 10 ° C was obtained on an apparatus for dissolving dry milk. The reconstituted milk was continuously supplied to the hydrocyclone, in which the pressure was maintained at 0.610 Pa. The vacuum treatment time was maintained by controlling the flow rate of the product for 60 seconds. At the exit from the hydrocyclone, milk was obtained with a gas content of 0.2%, a density of 1070 kg / m, and a viscosity of 17–10 Pa-s. The values of these parameters correspond to the values for condensed milk with a solids content of 24%. Example 5. A product with a solids content of 24% and a temperature of 40 ° C was obtained on an apparatus for dissolving dry milk. The reconstituted milk was continuously transferred to a hydrocyclone in which pressure was maintained. The vacuum treatment time was 60 seconds. Milk with a gas content of 0.21%, a density of 1071 kg / m, and a viscosity of 18–10 Pa s was obtained at the outlet of the hydrocyclone. The values of these parameters correspond to the values for condensed milk with a solids content of 24%. Example 6 A product with a solids content of 24% and a temperature of 70 ° C was obtained on an apparatus for dissolving dry milk. The reconstituted milk was continuously supplied to the hydrocyclone, in which the pressure was maintained at 29.51 (. The vacuum treatment time was 60 s. Milk was obtained at the exit from the hydrocyclone with a gas content of 0.2% density of 1070 kg / m, viscosity 1510 Pa s. These parameters correspond to the values for condensed milk with a dry matter content of 24%. Example 7. A dry matter content of 36% and a temperature of 10 ° C was obtained at the dissolving milk solids unit. The recovered milk was continuously sent to the hydrocyclone, the pressure was maintained at 0.4-ICf Pa. The vacuum treatment time was maintained by controlling the product flow rate and was 180 s. Milk with a 0.3% gas content and a density of 1108 kg / m and a viscosity of 50-10 Pa was obtained at the exit of the hydrocyclone. the parameters correspond to the values for condensed milk with a dry matter content of 36%. Example 8. A dry matter content of 36% and a temperature of 40 ° C was obtained at an apparatus for dissolving dry milk. The reconstituted milk was continuously sent to a hydrocyclone, in which a pressure of 510 Pa was maintained. The vacuum treatment time was 180 seconds. At the exit from the hydrocyclone, a gas content of 0.25%, density of 1109 kg / m, viscosity of 4510 Pa-s was obtained. The values of these parameters correspond to the values for condensed milk: With a solids content of 36%. Example 9. A product with a solids content of 36% and a temperature of 70 ° C was obtained on an apparatus for dissolving dry milk. The reconstituted milk was continuously sent to a hydrocyclone in which the pressure of 24 UPa was maintained. The vacuum treatment time was 180 seconds. At the exit from the hydrocyclone, milk was obtained with a gas content of 0.22%, a density of 1108 kg / m, a viscosity of 55lOTIa-c

Table 1

Table2 The values of the indicated parameters correspond to the values for condensed milk with a solids content of 36%. Modes of vacuum processing of milk and the results for all examples are presented in table. 2. As can be seen from the table. 2, the application of the proposed method of preparing reconstituted milk to mechanical and heat treatment allows, under certain vacuum regimes, to significantly shorten the time it takes for the reconstituted milk to achieve the physicochemical properties of natural milk. The time is shortened from 3-4 hours to 10-180 seconds. Iw. 0 SO 60 90 720 rmin FIG. 2 P70-f / 7a Or W I 20 0 60 BO t C FIG. 5 Pressure Relief

Claims (1)

METHOD FOR PREPARING RESTORED MILK FOR MECHANICAL AND HEAT TREATMENT, which involves the dissolution of milk powder in water, characterized in that, in order to accelerate the achievement of the physicochemical properties of natural milk, after dissolving it. subjected to vacuum treatment at a pressure of 0.4 10 * -37,540 ^s Pa for 10-180 s depending on the temperature of the milk and the dry matter content in it. 7020 -------- ¹ - ¹ ------- ¹ - About 50 720 780T, min FIG. 7