Theory and practice of meat processing

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Vol 1, No 4 (2016)
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4-10 682

Slaughter products are good source of bioactive substances with different biological effects. Nowadays, approximately 220 functional peptides consisting of 2–10 amino acid residues have been identified. In this study, the biological activity of medium-molecular-weight substances (5–30 kDa, Mw) and low-molecular-weight substances (less than 5 kDa, Mw) extracted from aorta of Sus scrofa were investigated in vitro. Medium-molecular-weight and low-molecular-weight fractions possessed a tissue specific effect on organotypic tissue cultures of chicken embryos and laboratory rats. Biological activity depended on molecular weight. Medium-molecular-weight fractions possessed higher effect on aortas explants of chicken embryo: area index of cellular monolayer was 56.6±5.2 % (area index of the monolayer was 37.47±3.27 % for low-molecularweight fraction) in comparison with control explants. The low-molecular-weight fractions stimulated aortic tissues explants of aging rats — area index exceeded area index formedium-molecularweight fractions by more than 30%.

11-18 725

Chicken meat is an important item in the Syrian diet. The increasing production of chickens and their potential in restaurants and food service operation implies the need for more detailed information regarding their quality and nutrient retention. Cooking methods have different effects on the values of nutrients of chicken. Therefore, this study was carried out to evaluate the effect of microwave cooking in amino acids composition of chicken meat (breast &thigh) as compared with some conventional methods, i.e. boiling, pressure and roasting

19-27 640

The need to renew the safety criteria for meat raw material used in production of fermented sausages was determined. The presence of the enterotoxigenic S. aureus strains in meat raw material was established. The method was mastered and the PCR approaches to identification and screenings of enterotoxigenic strains and their toxins in meat raw material were proposed. In order to identify enterotoxigenicity of detected staphylococci, the conservative regions of the S. aureus target gene sequences responsible for production of different types of enterotoxins (A, B, Е, С, D) were found and studied. In addition, short fragments of a nuclear acid (primers) corresponding to these revealed genes were constructed. As a result of identification, it was established that two isolated strains of S. аureus were enterotoxigenic. One of them produced type А and Е toxins (strain NG1) and another produced type С and Е toxins (strain NG2). The sensitivity and specificity of the real-time PCR method allowed not only identification of pure cultures but also screening of enterotoxigenic strains and their toxins in a product. The use of this method in the production control for the presence of the enterotoxigenic strains of S. aureus in meat raw material used in fermented sausage manufacture was recommended.

28-42 656

New meat products with immunomodulatory effect creation method reflecting differential characteristics of technological stages of manufacture of those types of meat products, including issues on the selection of primary and secondary raw materials, guidelines for development of formulations and production technologies, legislative requirements towards its labeling, etc, has been developed for the first time. A list of prospective meat raw materials for the manufacture of products with immunomodulatory effect was established: beef, pork, rabbit meat, broiler chicken meat, turkey, veal, ostrich meat, which have high content of protein (14,3– 21,7%), low content of fat (1,2–16,1%), excluding pork (33,3%), high levels of minimum amino-acid score (90,0–104,0%), protein quality indicator(0,91–1,64), essential amino acid index (1,16-1,25), coefficient of utility of amino acid content (0,72–0,86) and close to optimum fatty acid content, and also contain a great number of vitamins and minerals which play a significant role for immunity improvement. It was determined that the following functional ingredients are recommended to use: amino acids (valine, leucine, isoleucine, methionine, threonine, arginine, tryptophan, lysine, histidin, phenylalanyl), vitamins and provitamins (C,E, beta-carotene, B vitamins(Bc, B12, PP, etc.), P(bioflavonoid complex), H, K), minerals (calcium, magnesium, iron, cuprum, zinc, manganese, selenium), polyunsaturated fatty acids omega-3 and omega-6, pseudo-vitamins (L-carnitin, coenzyme Q10), polysaccharides and peptides naturally occurring(squalen, B-Carotene), ginger, shiitake mushrooms, probiotics and prebiotics, glutathione, indole and lycopienes, bioflavonoids, L-arginine, N-acetylcysteine, gel from seaweed «Lamifaren». The use of the developed meat products with immunomodulatory effect creation method by process engineers of meat processing factories will allow them to form a single scientifically grounded approach during the development, launching into manufacture and organization of industrial manufacture of functional meat products, ensuring the compliance of quality and safety indicators of innovative products with legislative requirements, applied to meat products, taking into account nutritional habits and containing a well-balanced set of functional ingredients with immunomodulatory effect, the consumption of which will promote immunity improvement that will positively affect health promotion.

43-50 609

The concept of «ideal product» is proposed for the study of mass transfer during partial freezing of food products by freezing plate. The ideal product is a product, in which number of factors affecting the «real product» (meat) are excluded. These factors include chemical composition of meat, quality grade of raw material (NOR, DFD, PSE), cryoscopic temperature that determines the degree of water transformation into ice, the phenomenon of osmosis, rate of freezing, etc. By using the concept of «ideal product» and its implementation in a physical experiment, it is proved that the “piston effect” causing the migration of moisture is due to frozen crust formation during partial freezing of the body. During partial freezing of the product by freezing plate, «ideal» and «real» food environment is transformed from closed system into open one with inflow of moisture to unfrozen part of the body. In the «ideal product», there is an expulsion of unfrozen moisture from freezing front, so the water appears on the body surface. Thus, the displacement of moisture increases by the same law, according to which the thickness (weight) of frozen layer increases. During partial freezing of ground meat, moisture does not appear on the surface of the product, but hydrates the unfrozen part of meat. The reason of this phenomenon is the expulsion of water during formation of frozen crust and water-binding capacity of meat.

51-56 833

The studies of meat and fat colour and marbling in Longissimus dorsi of different cattle — beef-producing (Aberdeen-Angus,Herefordbreeds) and dual-purpose (Simmental, Black-and-white breeds) — allowed to define groups by the colour values according to Lab international colour model. Measurements were performed 24 hours post-mortem between 12th and 13th ribs. It was found that different ranges of meat colour differed primarily in L* (lightness) and a* (redness) values, while b* (yellowness) values did not significantly differ. The highest differentiation between ranges of fat colour was noted in b* values, whereas L* and a* slightly differed. Moreover, visual assessment of beef marbling by four grades (small, moderate, good, and rich) and instrumental (microstructural) analysis using a computer image analysis system were carried out. The morphometric study of marbling was conducted in accordance with the principles of system quantitative analysis. To perform quantitative measurements, object analysis parameters (area) were specified. Both automatic and manual measurements of specified parameters were used. The study of Longissimus dorsi marbling established high agreement between visual and instrumental evaluations of marbling.

57-64 464

It was established that inclusion of black radish homogenate into model minced meat from different meat types (beef, pork, chicken) facilitates an increase in a degree of system hydrophilicity. In the experimental samples, the water binding capacity increased with an increase in the radish homogenate content at a level of 10, 20, 30, 40, 50% of meat weight. For example, in minced beef, it increased from 68% (control) to 80% (50% of black radish homogenate), in minced pork from 55 to 73%, in minced chicken from 72 to 82%, respectively. An increase in water binding capacity in model minced meat was due to a pH shift from 5.9–6.05 to 6.25– 6.43 (depending on a meat type) and the content of neutral salts in the dispersion system of the radish homogenate. An increase in moisture holding capacity was also established in model minced meat. The values varied from 10% (models with minced chicken) to 25% (minced pork) compared to control. In model minced meat, fibers and pectin substances of the black radish strongly bind water and act as a system stabilizer after thermal treatment. It was found that addition of the black radish homogenate in minced meat systems from different meat types increased the functional and technological indicators.

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