SU1666023A1 - Concentrated sterilized milk production method - Google Patents

Abstract

The invention relates to the dairy industry. The aim of the invention is to improve the quality of the finished product, reduce energy costs and save metal. To obtain condensed sterilized milk, heat treatment of the milk, normalization and concentration by ultrafiltration at 40 - 60 ° C and a pressure of 0.15 - 0.6 MPa are carried out to a mass fraction of dry substances of 29 - 35%. 4 tab.

Description

This invention relates to the dairy industry, in particular, to a method for producing condensed sterilized milk.

The aim of the invention is to improve the quality of the finished product, reduce energy costs and save metal.

The method is carried out as follows.

The milk is heat treated, then it is normalized and the normalized milk is subjected to concentration by ultrafiltration at 40-60 ° C and a pressure of 0.15-0.6 MPa to a mass fraction of dry substances of 29-35%.

Concentration of milk by ultrafiltration allows to obtain a heat-resistant product even at a mass fraction of dry substances of 29-35%, and also not to carry out an energy-intensive homogenization process as a result of the homogenizing effect that occurs during the process of ultrafiltration processing. The mass fraction of dry substances of the product is 12-23% higher than in products obtained by known methods. Increasing the concentration of milk can increase the turnover of sterilizers, remove products from a unit of production area, and also save a significant amount of tin per package (see Table 1). The lack of technological operation for the introduction of stabilizer salts reduces the cost of production and reduces its labor intensity.

Improving the quality of condensed sterilized canned milk produced by the proposed method of production is achieved by increasing the biological value of the product, which depends mainly on the fractional and amino acid composition of proteins.

Table 1 presents the comparative data of the chromatographic analysis of the amino acid composition of the condensed sterilized canned food according to the proposed method, according to the known production. From table 1 it can be seen that the number of essential amino acids in new products

ABOUT

Ltd

go

CJ

above. The value of lysine in condensed sterilized milk with a mass fraction of dry substances of 29% is 61.8% higher, and with 35% of dry substances is 2.5 times more than the known. The number of essential amino acids in the proposed products also exceeds their content in the known.

An indirect indicator of biological value, characterizing the degree of protein attack by proteolytic enzymes of the gastrointestinal tract, is the in vitro digestibility of proteins.

Table 2 presents data on the digestible ™. Analysis of the data in Table 2 allows judging the identity of the attackers with proteolytic enzymes in the sections of the gastrointestinal tract in both products, and the total digestibility indicates the high degree of attack of the proteins by the enzymes of the stomach and intestines.

The composition of the main components in the products according to the proposed production method differs from the traditional one in the following way: the mass fraction of mineral substances is reduced by 60%, lactose is almost 2 times, and fat is increased by almost 60%. Protein is contained in condensed sterilized milk with a mass fraction of dry substances of 29% to 45% more compared with the known, and from 35% of dry substances - 2.4 times.

The concept of nutritional value includes an indicator of energy value (caloric value), which is 178.8 kcal for a product with a mass fraction of dry substances of 29%, and from 35% - 201.8 kcal, which in comparison with the known method is in the first case, 32.4% more, and in the second - 49.5%.

The reduced mass fraction of lactose in the product allows the product to be consumed by persons suffering from galactosymy.

The lower mass fraction of dry substances in the product (29%) is taken at the level of the known. Concentrated sterilized milk contains a mass fraction of dry substances of 28.5%, which is the maximum possible by the traditional technology. The upper limit (35%) of solids allows the global level to be exceeded for condensed sterilized preserves, which is 31%, provided that it is sterilized in a stream with subsequent aseptic filling.

At the same time, the mass fraction of solids of 35% is optimal, since with an increase in the content of solids the heat resistance decreases sharply. So, for the condensed milk with a dry mass fraction

substances of 25% and higher, obtained by evaporation;

ten times, so you need to make

various stabilizer salts. Otherwise

the milk is curtailed during the heat treatment. In connection with this, one of the main indicators of the quality of sterilized canned milk is the heat resistance index, which characterizes the resistance to thermal coagulation, which is determined by the mass fraction of dry substances, including the ratio of calcium and magnesium salts. In a known method, so-called stabilizers are added to improve heat resistance, which are deficient and affect the quality of the product, causing a foreign taste.

Condensed sterilized canned milk, obtained according to the proposed

0, the production method, according to which the concentration is carried out by ultrafiltration, has a high heat resistance due to a decrease in the amount of salts and a change in their ratio. The concentrate can withstand sterilization at 130 ° C for 12-16 minutes, while milk condensed in a vacuum apparatus is only 2-3 minutes. In addition, the concentrate can withstand sterilization without adding

0 any stabilizer salts. Data on the heat resistance of the product are presented in table.3.

The optimal parameters of the ultrafiltration process are established: pressure

5 at the inlet of 0.15-0.6 MPa, temperature 40-60 ° C, the flow rate in the filter channel 2-6 m / s.

The amount of active acidity in the process of ultrafiltration concentration varies slightly, its fluctuations are 0.2-0.4 pH units. At the same time, the size of the buffer capacity increases both in acid and alkali, which indicates an improvement

5 technological properties of the concentrate. And consequently, this ensures the achievement of a positive effect. At change of the specified parameters achievement of a positive effect is impossible.

0 In the process of ultrafiltration concentration, along with an increase in the concentration factor, microorganisms accumulate that are larger than the pores of ultrafiltration membranes. However, this fact does not characterize

5 reduction of sanitary and hygienic indicators of the product. In the proposed production method, just as in the traditional one, the destruction of microorganisms by pasteurization of the raw material and

subsequent sterilization of the concentrate, so the finished product is industrial sterile,

A study of the microbiological indices of ultrafiltration concentrates — the visible composition, as well as their number, which did not exceed 103 cells per 1 g of the product under investigation, testifies to quite good sanitary and hygienic indicators of the product. The temperature parameters of sterilization ensure complete inactivation of the microflora present in the concentrate and obtaining sterile product.

During storage, the thickening is caused by the presence of calcium salts in the product. Due to the fact that the main mineral substances that affect thickening are removed during the concentration process, in contrast to vacuum thickening - evaporation, the products according to the proposed production method are characterized by resistance to thickening in storage,

Experimental data indicate a rather high heat resistance of the product according to the proposed production method in comparison with the traditional one, and without adding any stabilizing salts.

Example 1. 1000 kg of normalized milk with a mass fraction of dry substances of 11.5% (fat / SOMO 0.353) is subjected to ultrafiltration concentration at 40 ° C and a pressure of 0.15 MPa. The result is 270.8 kg of ultrafiltration concentrate with a dry mass fraction of 29% (including,%: fat 12.3, protein 10, 70, lactose 5, mineral substances 1). The resulting concentrate is packaged in cans and sterilized at 120 ° C in

20 min. The finished product is stored at 0-10 ° C. The yield of the finished product is 270.8 kg. The finished product contains 47% less lactose, which makes it possible to consume persons suffering from galactosymy. The chemical composition of the product is presented in table 4,

Claims (1)

Example 2, 1000 kg of normalized milk with a mass fraction of dry substances of 12.4% (fat / SOMO -0,41) is subjected to ultrafiltration concentration at 60 ° C and a pressure of 0.5 MPA. The result is 246.7 kg of ultrafiltration concentrate with a mass fraction of solids 35% (including%: fat 17.0, protein 12.0, lactose 5, mineral substances 1). The resulting concentrate is packaged in cans and sterilized at 120 ° C for 20 minutes. The finished product is stored at 0-10 ° C. The yield of the finished product is 246.7 kg. The finished product contains 47% less lactose, which makes it possible for individuals to consume. suffering from galactosymy. The product is characterized by increased nutritional and biological value, its composition is presented in Table 3. Claim Method A method of producing condensed sterilized milk with carrying out milk preparation processes, normalization with respect to fat and SOMO, heat treatment, packaging, concentration and sterilization, characterized in that, in order to improve the quality of the finished product, reduce energy costs and save tin, milk heat treatment is carried out before normalization , and the concentration is carried out by ultrafiltration at a temperature of 40-60 ° C and a pressure of 0.15-0.6 MPa to a mass fraction of dry substances of 29-35%, Table 1 table 2 Renders to the absence of visible coagulation Table 3 Table 4