A STUDY OF THE PROBABILISTIC STATES OF MACHINETRACTOR AGGREGATES FOR WHEAT CULTIVATION

This paper applies Markov's theory of stochastic processes (Graph theory) to identify the probability of the machine-tractor aggregate being in each of the machine states adopted by the model. It features a graph of the states of a machine-tractor aggregate (Machine-status) operating in plant growing that allows us to determine the probability of the aggregate being in any of the states considered as basic. It proves that with the increase in the level of reliability of the aggregate, in this case its flawless performance, represented by the non-intermittent operation time indicator (time for trouble-free work), the probability that the aggregate will be in a functional state increases

Effect of superficial treatment with new natural antioxidant on salmon (Salmo salar) lipid oxidation

Lipid oxidation is one of the main factors responsible for the quality loss in refrigerated and frozen stored fish products. The aim of the study was to evaluate the effect of superficial treatment of Atlantic salmon (Salmo salar) with dihydroquercetin (DHQ) solutions on the hydrolytic and oxidative changes in fish lipids during refrigerated storage. It was found that treatment with DHQ solution (1.0 g l−1) reduced approximately twice the free fatty acids content of chilled stored salmon. After 11 days of storage at 1 °С, the contents of hydroperoxides (HPO) and 2-thiobarbituric acid reactive substances (TBARS) of these samples decreased with 45.00 and 0.91 mg MDA/kg, respectively. The share of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) in control and experimental samples did not differ significantly (P>0.05). Results obtained show that the superficial treatment of salmon with DHQ solution (1.0 g l−1) delayed the hydrolytic and oxidative changes in fish lipids significantly, thus preserving the salmon freshness up to 11 days of storage at 1 °С

Lipolytic and oxidative changes in acoustically assisted frozen fattened duck liver

The delicate structure of the fattened duck liver requires rapid freezing as quickly as possible. Acoustically assisted freezing meets both the requirement for quick freezing and energy efficiency. For the purpose of the experiment, a fattened duck liver “foie gras” was used. The degree of lipolysis (acid value) and primary (peroxide value) and secondary (2-thiobarbituric acid value) products of lipid oxidization were examined at 2 h post mortem. The oxidative changes were evaluated after conventional (CF) and acoustically assisted freezing (AAF) and at the 6-th and 12-th month of storage at -18°C. Both time storage and type of freezing affect the degree of lipolysis. The duck liver after AAF had higher degree of lipolysis at the 12-th month of storage at -18°C. The peroxide value increased almost 2 times in both fattened duck livers (CF and AAF) during the 6 months of storage at -18°C and stabilizes until the 12-th month. A conclusion was made that the acoustically assisted freezing of the fattened duck liver did not promote higher lipid oxidation compared to the conventional type of freezing

Color dynamics of cooked sausages after nitrite reduction and incorporation of biologically active substances

In most cases, the color of meat products is the factor influencing consumer choice. It’s formation and preservation is the highest priority. Sodium nitrite is used for fixation of the pleasant pink-red color, but also has a negative image from the consumers oriented towards clean label products. The valorization of rose oil-industry by-products by their incorporation in foods as natural additives is growing research area. The formulated cooked sausage recipes, contain blend of three biologically active substances (BAS) and different level of sodium nitrite reductions: AN100, AN75, AN50, AN25, AN0 and control - C. Color attributes CIE L*, a*, b* were assessed during 14 days of chilled storage (0-4 °C) and their changes in dynamics were evaluated every 10 min for an hour at air exposure. The incorporation of the inhibit the oxidation of meat pigments during the chilled storage and slowed down the fading of the pinkred color of the cross-cut surface during the 60 min of air exposure. The sausages produced with up to 50 % nitrite reduction and the blend of three BAS have lower lightness (L*), higher intensity of the red color (a*) and lower yellowness (b*) of the cross-cut surface in comparison to the control

Quality, Microstructure, and Technological Properties of Sheep

The objective of this study was to explore the effect of 24 and 48 h alkaline (2% pentasodium tripolyphosphate), acid (2% sodium lactate), and water-oil marinating (water : sun flavor oil = 1 : 1 and 2% salt) as well as brine soaking (2% salt) on microstructure, changes in protein, and lipid fractions and technological properties of sheep (m. Longissimus dorsi). Strong myofibrillar fragmentation after 48 h alkaline marinating was observed. Significant swelling and increasing of spaces between myofibrils were found after 24 h brine soaking. Marinating in water-oil emulsions did not show a significant impact on the muscle microstructure. Alkaline and acid marinating as well as salt soaking promote the myofibrillar protein solubility and increased the free amino nitrogen content. After 24 h acid and 48 h alkaline marinating SDS-PAGE electrophoresis showed increasing of 25–30 kDa protein bands. The results obtained for the lipid and protein oxidation confirm prooxidant action of the sodium lactate (2%) and antioxidant effect of polyphosphates (2%) in marinated sheep

Lipid Peroxidation in Muscle Foods: Impact on Quality, Safety and Human Health

The issue of lipid changes in muscle foods under the action of atmospheric oxygen has captured the attention of researchers for over a century. Lipid oxidative processes initiate during the slaughtering of animals and persist throughout subsequent technological processing and storage of the finished product. The oxidation of lipids in muscle foods is a phenomenon extensively deliberated in the scientific community, acknowledged as one of the pivotal factors affecting their quality, safety, and human health. This review delves into the nature of lipid oxidation in muscle foods, highlighting mechanisms of free radical initiation and the propagation of oxidative processes. Special attention is given to the natural antioxidant protective system and dietary factors influencing the stability of muscle lipids. The review traces mechanisms inhibiting oxidative processes, exploring how changes in lipid oxidative substrates, prooxidant activity, and the antioxidant protective system play a role. A critical review of the oxidative stability and safety of meat products is provided. The impact of oxidative processes on the quality of muscle foods, including flavour, aroma, taste, colour, and texture, is scrutinised. Additionally, the review monitors the effect of oxidised muscle foods on human health, particularly in relation to the autooxidation of cholesterol. Associations with coronary cardiovascular disease, brain stroke, and carcinogenesis linked to oxidative stress, and various infections are discussed. Further studies are also needed to formulate appropriate technological solutions to reduce the risk of chemical hazards caused by the initiation and development of lipid peroxidation processes in muscle foods

Diffusion of lipolysis and lipid oxidation in fried and oven-baked mackerel

The processes of lipolysis and lipid oxidation during frying, oven-baking and subsequent storage under refrigeration of mackerel previously stored at −18 °C for six months were studied. The lipids and fatty acid content of the fish were characterized. The acid number, peroxide number, thiobarbituric acid reactive substances, and the conjugated diens and triens were traced dynamically. It was observed that the defrosted mackerel was characterized by advanced stage lipolysis and accumulated lipid oxidation primary products. During the frying and oven-baking of the defrosted mackerel, the lipolysis spread throughout the fish. The hydroperoxide content decreased 4.7–4.9 times and mostly secondary derivatives of lipid oxidation accumulated. During the process of frying the mackerel, the lipid oxidation chain was widespread. More conjugated triens and fewer conjugated diens were formed, and the polyene indices increased. In contrast, oven-baking did not cause changes to the conjugated lipids, and the polyene indices decreased more than 60%

State and Perspectives of Development of Buffalo Breeding in Bulgaria

In the last 45 years the production of buffalo milk in the world increases with much higher rates compared with the cow milk. This is a result of the process of restructuring of the buffalo breeding towards production of milk and meat. In Bulgaria this restructuring ended with the full replacement of the aboriginal Bulgarian buffalo for work, milk and meat with the new breed Bulgarian Murrah, which possesses high productive qualities for milk and meat. It is used as a genetic source for improving the milk productivity in dozens of countries on the four continents of the world. In the next years, as a EU member, the national economy of Bulgaria will endure significant changes, which will influence positively the agrarian production and respectively the buffalo breeding. Therefore the view in the future of this perspective branch requires a profound analysis of the buffalo breeding, as well as the business environment, in which it will develop. Based on this analysis and the specific biological specifics, methodological and methodical conditions in the study, the development of the buffalo breeding in 2005-2020 is foreseen. Special place in it occupies the production of high quality tribal material for the domestic needs and the needs of the foreign markets. Suitable productive structure of acknowledged Bulgarian brands of milk and meat products with high VAT is mentioned. The tendencies and directions towards the perspective economi-organizational structures, technological changes and the increase of the incomes on the whole chain from the connected with the business of buffalo breeding activities are defined. Necessary attention is drawn to the contemporary requirements to the comfort of the animals, ecological purity of the final food products and the protection of the environment from pollutions.

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Emergency archaeological investigations on the territory of ancient Sexaginta Prista at Rouss