编号 4 (2015)

The propagation of ultrasonic waves in thin plates/waveguides by immersing them in the milk, as an example of multicomponent fluid was investigated. Six samples of milk from one producer ( the nominal fat levels shown on the package were 0.5, 1.5, 2.5, 3.2, 3.5, 6.0 %) were taken to study. Principle parameters of the samples were analyzed using the analyzer MilkoScan FT120. The attenuation coefficients of the symmetric Lamb wave and horizontally polarized normal waves depending on the fat content of milk were measured with ultra-sonic viscodensitometer. Construction of the ultra-sonic viscodensitometer and its measuring device are described. Obtained from ultra-sonic measurements numeric values of the shear viscosity correlate well with measured values of the milk fat content. As far as calculation of milk density using ultra-sonic measurements with the aid of the Lamb waves is concerned were can say that though differences of the measured meanings from the meanings measured with MilkoScan FT 120 are small enough when compared with absolute value (not exceed 8 %) additional study is needed to interpret the results. The ultra-sonic measurements show that with increase of milk fat content density of the milk tends to grow (about 1 %) while the density corresponding to the measurements with MilkoScan FT 120 gives reverse dependence (decrease is 0.6 %). The experiments carried out demonstrated that application of waves in thin plates can considerably improve informativity of the existing ultra-sonic devices for control of milk quality. The propagation of ultrasonic waves in thin plates / waveguides by immersing them in the milk, as an example of a multi-component fluid, was investigated. The attenuation coefficients of symmetric Lamb waves and horizontally polarized normal waves depending on the fat content of milk were measured. Obtained from ultrasound measurements numerical values of the shear viscosity correlate well with the measured values of the milk fat content. The experiments showed that the use of waves in thin plates can significantly improve informativity of modern ultrasonic instruments for monitoring milk quality.

Growth of number of the people having so-called «civilization diseases»: obesity, diabetes , cardiovascular, etc. causes the necessity of development of technologies of products with the lowered caloric content. The problem of excess consumption of food nutrients, in particular fats and carbohydrates, becomes especially actual. The importance thus gets search of effective simulators of fat. We offered technology of low-lactose ice cream with mikropartikulyaty serumal proteins, imitating a fleyvor of milk fat. As raw materials for its receiving used the subcheese serum modified by methods of ultrafiltration and a mikropartikulyation. Mikropartikulit contains agglomerates of serumal proteins with a size of particles similar to balls of milk fat. On the organoleptic indicators mikropartikulit it is similar to milk cream: has uniform, moderately viscous, a consistence, white color and a pure dairy smell. Significant power-intensive component of a diet is sucrose. For the purpose of replacement of these refined carbohydrates, and also improvement of consumer properties of a ready-made product and it is offered to pass solutions of the problem of intolerance of lactose its fermentativny hydrolysis. The new food composition for ice cream allows to replace partially refined and high-power valuable components of traditional ice cream (whole milk, butter, cream and sucrose) and to enrich a product with serumal proteins, irreplaceable amino acids, ascorbic acid, Riboflavine, niatsine and a pyridoxine. Fermentativny hydrolysis of lactose reduces probability of its crystallization in the course of storage of ice cream and formation of defect «sandiness». Selection of a fermental preparation for lactose hydrolysis is carried out, optimum conditions of process of bioconversion of lactose are established. The fermental preparation Maxilact® provides the maximum extent of hydrolysis of lactose of 90 % under the following optimum conditions: the dose of introduction of 0,68 g/dm 3, temperature is 39 °C and duration of process is 3 h 45 min. The proposed technological solution provides replacement of milk fat by 65 %, sucrose by 43 % and decrease in caloric content of ice cream by 41 % that allows to carry it to products of healthy food and to realize the closed production cycle at the enterprises of dairy industry.