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Vol 3, No 2 (2020)
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4-8 145

Porous medium are products of processing in food, agricultural, chemical and many other industries. Calculations of processes with wet porous medium are based on capillary properties of the liquid in a pore space. The capillary properties of liquids in porous media are established in pore models in the form of thin tubes of circular or slit transverse sections. The intensity of the processes occurring in it depends on the nature of the filling of the pore space with liquid. Filling with liquid and the formation of a capillary layer is possible only in small pores. However, there is no analytical justification for the transverse pore size, more than which it cannot be filled with liquid by capillary forces. With this in mind, the concept of the limiting transverse size of a capillary for a liquid under conditions of complete wetting is introduced. The limiting size calculation is based on two conditions: the shape of the axial section of the meniscus surface has the appearance of a semicircle and its extremum point is located at the level of the free surface of the fluid supplying the capillary. A capillary column cannot form in larger pores. The absence of formulas for calculating capillaries of the limiting sizes can introduce a significant error into the analytical calculation of the moisture content in the capillary layer of a liquid in porous media and moisture transfer processes. The aim of the study was to obtain formulas for calculating the limiting (largest) sizes of capillaries of a circular, flat slit section and annular transverse sections with complete wetting of their walls. For the conditions above, it was identified that the limiting distance between the walls was independent from annular capillary diameter. The formulas for the limiting transverse sizes of the flat slit and annular capillaries turned out to be the same under the assumptions above. This indicates a weak dependence of the limiting size of a slit capillary on the curvature of its transverse section. Examples of calculations of capillaries of the limiting sizes are performed.

9-13 195

The theoretical and practical aspects of the formation of free fat in milk, cheese and cheese products with vegetable fats are considered. The amount of free fat in milk depends on the integrity of the fat globules membranes, which are affected by: ineffective emulsification of fat during the synthesis of milk in the cow’s udder (authentic fat) and physic-mechanical factors in the milk processing after milking (destabilized fat). Free fat, primarily subjected to oxidative processes and lipolysis, reduces the quality and ability to store milk. For cheese products, the presence of free fat, available for lipolysis and oxidation, is a prerequisite for obtaining high-quality products. Characteristics of the production of cheese products with vegetable fats, providing for the preliminary emulsification of vegetable fat in skim milk, contribute to the formation of denser membranes on the surface of fat globules, consisting mainly of casein micelles and whey proteins. This is the reason for the formation of a more closed structure of the fat phase with low availability of fat for enzymes and oxidizing agents. The low availability of fat in the structure of cheese products with vegetable fats is one of the factors that worsen their organoleptic characteristics. In order to increase the amount of available fat in the production of cheese products with vegetable fats, it is advisable to use additional enzyme preparations or cultures of microorganisms that activate proteolysis and lipolysis.

14-17 135

In this research the results of analytical studies are presented, which prove the lack of data on influence of aging process on dispersion of structural elements in ice cream with fat mass fraction of 6% or less, and experimental studies on definition of dispersion of air phase and ice crystals in milk ice cream. It was found that the process of the mix aging doesn’t significantly affect the dispersion of air phase and ice crystals in ice cream with fat mass fraction of 3%. In ice cream with fat mass fraction of 6%, made from a mix, the dispersion of the air phase increased along with the aging process, and the size of almost all air bubbles were less than 50 microns. At the same time the dispersion of ice crystals increased by no more than 10%. The decrease in dispersion of the air phase during the storage period was observed, mostly in ice cream with a fat mass fraction of 6% produced of the cured mix. The research results have the practical importance as they justify the need for the aging process in the production of ice cream with a low mass fraction of fat and determine the necessity of further research in this area.

18-23 152

One of the promising raw materials types for alcoholic beverages production, which have a peculiar aroma and taste, is the ashberry (red), widespread throughout the Russian Federation. The aim of the research was to develop an innovative technology for alcoholic beverages from the red ashberry based on the study of the raw materials biochemical composition transformation during its processing, maceration, fermentation, distillation, as well as its effect on the volatile components composition of distillate and the processing conditions of the finished alcoholic beverage. Fermented pulp of red ashberry, distillates and alcoholic beverage blends from ashberry were used as objects of the study. To determine the organoleptic and physico-chemical indicators in the work, standardized analysis methods and certified methods were used. The effect of various yeast races and fermentation conditions on the change in biochemical composition of the red ashberry pulp was studied. For this raw material type fermentation, recommended Siha 3 yeast race. The positive effect of the Vitamon Combi fermentation activator on the fermentation efficiency and the formation of qualitative characteristics of the fermented pulp, including its amino acid composition, is shown. It was established that the optimal conditions for fermentation is the anaerobic regimen at a temperature of no higher than 22 ºС. The effect of fractional distillation operating parameters in a direct distillation unit on the volatile components’ composition and concentration in ashberry distillate is studied. It is recommended to obtain a high-quality distillate to carry out the selection of the head fraction in the amount of 2.5% of the distilled pulp volume, and the selection of the tail fraction to start when the strength in distillate reaches 45% vol. It is shown that within 30 days of exposure in the distillate, a certain chemical equilibrium is achieved and its taste and aromatic characteristics are harmonized. The blending conditions of the alcoholic beverage are determined and the technological processing modes are established to ensure its high consumer properties. The conducted studies have allowed to develop innovative technology for a new alcoholic beverage from red ashberry.

24-28 137

Using the rapid method of digital image analysis by the developed scanning flour analyzer the optical properties of flour (semolina) obtained in laboratory and production conditions from durum wheat of three years of harvest (2017–2019), namely the «yellowness» indicator and the color characteristic in the blue part of the spectrum, were determined. The semolina color was also evaluated by the Konica Minolta CR-410 colorimeter. It is established that the «yellowness» indicator and the color characteristic in the blue part of the spectrum did not change within the first 5 to 6 days after grinding. The change of these indicators for all the samples is observed in the period from 6 to 20 days after grinding, there with the «yellowness» indicator decreased by 25 to 40 relative units, the color characteristic in the blue part of the spectrum increased on average by 133,75 relative units. Over the next three months, there was no change of color (by both indicators). In the course of experimental work the optical properties change depending upon carotenoids content of flour (semolina) during its ripening was shown. The correlation dependence between the «yellowness» indicator of flour (semolina) and its carotenoids content is characterized by a high approximation coefficient. The dependence of the color characteristic of flour in the blue part of the spectrum on the content of carotenoids is characterized by an approximation coefficient equal to 0.9358, and is described as a polynomial equation. It shows, that with a low carotenoid content, the considered indicator is higher by an average of 1100 relative units compared to the color of samples with a carotenoid content from 0.70 to 1.21 mcg/g. At that during storage the optical properties of flour variety with the lowest carotenoids content remained practically the same. During 78 days of storage, there was no significant change of color characteristics of the industrial flour samples, studied from the eleventh day after grinding — 5–8 times higher than the average repeatability of the measurement results.

29-34 181

The aim of the study was to establish the possibility of improving the organoleptic characteristics of cheese products by introducing butyric acid into the composition of the used vegetable fat composition. Cheese products made using two fat compositions consisting of refined, deodorized vegetable fats, including those modified by interesterification, were studied. The experimental fat composition contained in its composition additional butyric acid added to the composition of triglycerides. The study of cheese products was carried out in the process of ripening and storage for 120 days in comparison with cheese, the fat phase of which is represented by milk fat. It was found that the degree of proteolysis, estimated by the ratio of total water-soluble nitrogen to total nitrogen, does not depend on the nature of the fat in the protein matrix. Milk fat in cheeses is more subjected to lipolysis than vegetable fats in cheese products. The addition of butyric acid to the vegetable composition in an amount of 0.8% increased the acidity of the fat phase by 0.1 mmol/100 g. According to the assessment of organoleptic characteristics, cheese with milk fat had the most pronounced cheese flavor and aroma, cheese product without butyric acid in fat phase had the least pronounced ones. A cheese product with a fat composition containing added butyric acid was close to cheese with milk fat in terms of the severity of cheese taste, rheological characteristics and the spectrum of volatile flavoring substances. It is concluded that the taste and aroma of cheese products have a positive effect on adjusting the fatty acid composition of vegetable fat compositions by introducing butyric acid into their composition.

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ISSN 2618-9771 (Print)
ISSN 2618-7272 (Online)