The article presents the results of experimental joint studies of changes in the viscosity and microstructure of milk at the enzymatic stage of gelation. Based on the statistical processing of the array of research results, it was determined that the viscosity change at this stage is not monotonic, as it is usually stated, but two-stage in the middle part and S-shaped, preceding the gel point, at its end. It was found that the S-shaped change in viscosity at the end of the enzymatic stage of milk coagulation coincides with changes in the microstructure of casein micelles and reflects the existence of a cooperative conformational phase transition in casein molecules of micelle clusters. A description of the possible mechanism of this phase transition is proposed. It was noted that the moment of the S-shaped change in the milk viscosity at the enzymatic gelation stage and the corresponding cooperative phase transition in casein micelles are a physical reflection of the gel point. The research results provide a better understanding of the mechanism of enzymatic coagulation of milk in a cheesemaking tank.
The indicators of quality and microbiological safety of frozen vegetable semi-finished products (for example, cut beet) processed in a microwave field for subsequent storage for 18 months at a temperature of minus 20±2 °C. Treatment with a microwave field was carried out under the following conditions: power 600 W and duration 5 min (180 kJ); power 1000 W and duration 4 min (240 kJ). It is established that treatment in the microwave field contributes to the preservation of consumer qualities of the product (total solids content, mass fraction of soluble solids, bound moisture content, microbiological effect) in the process of long-term low-temperature storage.
The article discusses the relevance of developing methodological approaches to the beer and soft drinks accelerated aging method in the market. The controlled indicators selection principles, mainly affecting the quality of the finished product, and the basic equation describing the dependence of changes in indicators on the main temperature factor are given. Studies of the influence of various physical factors (temperatures in the range of 50–60 °C, UV-radiation), both individually and jointly, on the physicochemical and organoleptic characteristics of packaged water for various experimental versions did not show statistically significant changes in the normalized parameters of the basic salt and microelement composition investigated water during storage. The optimal mode of accelerated «aging» of packaged water at an elevated temperature (up to 60 °C) and UV-radiation was established. In the case of soft drinks, thermostating was used when changing the temperature regimes (heat 50 ± 2 °C / cold 6 ± 2 °C) at an exposure time of 30 days, which made it possible to observe a decrease in taste and aroma compared with the control, as well as a decrease in sweetness and the appearance of a slight plastic taste for non-carbonated drink. The influence a temperature regime change on brewing products, which cannot be estimated using the existing method due to the high turbidity, is shown.
There are provided data on the work carried out at All-Russian Research Institute for Starch Products to create enriched low-protein pasta based on starch for nutrition the children sick with a phenilketonuria — a hereditary disease (group of fermentopatiya), the bound to violation of amino acids metabolism, mainly phenyl alanine. Optimization of children nutrition is the socially important direction of domestic policy of the Russian Federation since their health directly depends on the good balanced nutrition, especially it is important for the children having diseases of genetic character.
To expand the range of the enriched low-protein food the functional ingredients are picked up, recipes and technology of receiving three types of pasta are developed such as: noodles, vermicelli, «spider line», their nutrition and power values are defined. It is shown that in the received products protein content doesn’t exceed permissible value (<1.0%), fat from 3.3 to 3.6%, ashes — to 0.14%, carbohydrates no more than 88.0% that conforms to requirements imposed to reduced-protein products of baby food.
ISSN 2618-7272 (Online)