The aim of this article is to review literature data on the terminology, classification and physiological effects of dietary fibers. Results. The scientific studies on the terminology, classification and characteristics of various types of dietary fiber are presented, the sources of dietary fiber and their positive physiological effects are described. Nowadays no consensus definition has been given to the concept of dietary fibers. The authors point to dietary fibers being related to chemical compounds defined by structure, or functional properties, and/or a combination of both structural and functional properties. The authors noted one commonality in these definitions: each mentioned positive physiological effects. The modern classification system for dietary fibers is wide and diverse and can be based on origin, structure of polymers, solubility, ion exchange, sorption or physiological effect. Many studies have shown that dietary fibers can promote human health and help prevent specific chronic diseases that increase mortality and reduce life expectancy. Numerous healthful effects of the dietary fibers have been documented. These include curative and preventive effects for diseases such as obesity, certain types of cancers, cardiovascular diseases, diabetes, and constipation. Conclusion. Fibers are considered before other nutrients to ensure a healthy nutrition. Research continues to contribute new data on the effect of dietary fiber on the human body.
In connection with the active growth of poultry processing, the issue of rational use of poultry by-products is urgent. The paper proposes hydrolysis of the gizzards of broiler chickens and hens of the parent stock with bifidobacteria liquid concentrate (BLC) and Propionix liquid concentrated starter culture (Propionix LCSC). The effect of enzymatic treatment on changes in the structural components of the gizzards was studied using scanning electron microscopy (SEM) and determination of the dispersed composition. As a result of the research, the multiple regression equations and the response surfaces were obtained, which describe the optimal parameters of the gizzard´s hydrolysis process. The temperature and the time of hydrolysis are factors that have a significant effect on the degree of hydrolysis. The results of the structural and microscopic analysis confirm the high hydrolysability of the by-products by changing its structure and increasing the number of smaller protein particles. It was found experimentally that the gizzards of hens are more susceptible to the action of probiotic microorganisms’ enzymes compared to the gizzards of broiler chickens.
The aim of the study was to analyse the effects of transglutaminase on the physicochemical, technological, rheological, and microstructural indicators of minced meat with the addition of plant raw materials. The formulations of minced meat from beef trimming, hemp protein, and flax flour were optimized in terms of biological value and optimal content of essential amino acids. The addition of plant components in amounts greater than 18% caused an increase in the content of protein, fat, and ash in the minced samples. The rheological properties of minced meat samples without enzyme treatment changed depending on the proportion of plant raw materials. When the content of the flax flour was increased, the minimum ultimate shear stress and viscosity were observed, while the maximum values for these indicators were achieved in samples containing about 15% hemp protein, as well as in samples without plant additives. When adding transglutaminase to the formulation, increases in the ultimate shear stress and viscosity were proven for all combined minced samples. The combined minces, containing flax flour, had a more plastic structure and the lowest modulus of elasticity, while minces including 14% hemp protein or more than 87% meat components were identical to the control samples in terms of deformation and elasticity. In enzyme-treated minces, the plasticity of the samples reduced while density and elasticity increased. Transglutaminase treatment contributed to the formation of optimal technological properties of combined minces. Microstructural analysis showed the intermolecular bonds between protein particles in combined minced samples with the addition of enzymes. The research results have demonstrated the effectiveness of using transglutaminase in the composition of combined minced meat for the formation of a homogeneous and dense system with the necessary technological and rheological properties.
To adjust the nutritive and biological value of food products, it is advisable to combine meat and vegetable raw materials. The paper presents the results of study of the rheological and microstructural parameters of combined meat-vegetable minces. The mince includes beef trimming, hemp protein and flaxseed flour. The study results showed the minimum values of shear stress and viscosity of the mince system and increased indicators of total and plastic deformation in the samples of minced meat containing linseed flour in an amount of 10–15%. Samples of the meat-vegetable mince that contained 15% of hemp protein and not more than 5% of flax flour exhibited high stability of the meat system. Microstructural studies of combined minced meat revealed the presence of friable vegetable mass, starch grains and fragments of hemp and flax fiber. Samples with a predominance of hemp protein showed a denser and more uniform structure. Thus, the rheological properties of meat-vegetable mince systems depend significantly on the type and amount of vegetable materials introduced.
Enzymatic processes play a key role in the production of grain-containing food due to their effect on the nutritional properties, rheological characteristics, and contribution to improving the functional and antioxidant proprieties. Eight samples of beverages based on barley grain and hemp seeds were produced (control beverages and beverages fermented by bifidobacteria and propionic acid bacteria). It was found that lactic acid accumulated during fermentation alongside a gradual shift in the pH level in the acidic direction. A comparative analysis of the DPPH activity revealed the highest values for barley-based beverages, ranging from 71.0 to 100.7%, while for the hemp seed-based beverages, the DPPH activity was 64.1–97.9%. The maximum values of DPPH activity were observed during fermentation with a combination of bifidobacteria and propionic acid bacteria concentrates. The highest concentration of polyphenolic compounds and flavonoids was found in barley-based beverages fermented with Propionibacterium freudenreichii (1.26 mg GAE/g and 0.11 mg EQ/g) and a combination of Propionibacterium freudenreichii and Bifidobacterium longum (1.24 mg GAE/g and 0.14 mg EQ/g). Studies have shown an increase in the nutrient content for fermented beverages compared to the control samples. The barley-based beverages exhibited the largest average dynamic particle diameter, and all beverage samples showed a more uniform particle size distribution after microbial fermentation.
Меренкова Светлана Павловна. Кандидат ветеринарных наук, доцент кафедры «Пищевые и биотехнологии», Южно-Уральский государственный университет (г. Челябинск),
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