Decrease In Biological Value Research Articles

THE EFFECT OF PSOROPTOSIS ON THE PRODUCTIVE INDICATORS OF RABBITSY

Psoroptosis is a disease that is widespread and causes great economic damage to farm enterprises and individual rabbit farms, which leads to decreased body weight, deteriorated quality of meat and skins, slow growth and development of young animals, and a drop in prices for available animals. The study analyzed the effect of psoroptosis infestation on rabbits’ hematological parameters, live weight and quality of rabbit meat. For the experiment, 9 Soviet Chinchilla rabbits were used. The experimental group was infected by placing live mites in the auricles and laying crusts with mite eggs taken from the auricles of diseased rabbits. In the first days of infecting, the increase in body weight was lower by 15.6% in the experimental group of rabbits, and the animals lagged behind in growth and development. Erythropenia, hypohemoglobinemia, leukocytosis, anisocytosis and any other changes were found in the animals’ blood. Further, a significant decrease in biological value of rabbit meat was observed. When evaluating the biochemical composition of rabbit meat, it was found that a 14.2% increase in moisture and a 13.2% decrease in protein were observed in meat of the rabbits with psoroptosis.

The use of ultrasonic exposure in the production of functional beverages based on natural raw materials

The technology of drinks production makes it possible to create a variety of tastes and use various natural foundations. Expanding the assortment of “wholesome” and “functional” drinks reveals possibilities for controlling the process of biologically active substances entering the body. From a technological point of view, the drink is the most convenient model for creating new products, including the use of natural plant materials. For creating them, traditional extraction methods are often used. They have several drawbacks: they are long, laborious, occur when exposed to high temperatures, which leads to the loss of raw materials of biologically active substances, the taste of aroma, and a decrease in biological value. In this regard, the actual direction of improving technological solutions in this area is the application of the ultrasonic intensification of the extraction process method. Ultrasound can significantly reduce the duration of the process, increase the yield of biologically active target components and improve the organoleptic characteristics of beverage extracts [2]. The work is devoted to the study of the ultrasonic extraction method in the preparation of functional beverages. The obtained data indicate that the use of this method helps to reduce the time of the extractant saturation, increase the antioxidant activity and yield of extractive substances. This result helps to ensure higher organoleptic characteristics of drinks.

Technology and characteristics of boiled sausages enriched with dietary fibers of Plantago Psyllium l.

This study is based on the thesis that the lack of dietary fibers in the diet of the population is a problem that needs to be solved by the production of enriched mass-consumption products. The proposed formulation of boiled sausages includes a highest grade beef (as the main raw material), bold pork, chicken eggs and powder milk with different levels of replacement of pork for the flour from the husk of Plantago psyllium L. Sodium Nitrite was not added, the polyamide shells with a diameter of 60 mm were used. The technology of boiled sausages is described. The optimum dosage of flour (2.35%) from the husk of Plantago psyllium L. is defined through simulation. It is shown that the addition of this ingredient in boiled sausages leads to a slight decrease in protein, fat and an increase in the mass fraction of carbohydrates. However, within the examined limits it does not lead to a decrease in biological value. The additive positive effect of dietary fibers of Plantago psyllium L. husk (arabinoxylans) on the functional and technological properties and organoleptic characteristics of cooked sausages is defined. In this regard, there is the possibility of using the flour from the husk of Plantago psyllium L. not only as a functional food ingredient – dietary fiber, but also as a water-retaining agent that improves the consumer properties of the product. The expiry dates for boild sausages are set. These expiry dates have not decreased compared to the control samples and amounted to 7 days at a temperature of +2...+6 °C. The compliance with safety indicators of the developed products to the requirements of technical regulations is shown. The regulatory documentation is approved and three patents are received. Economic efficiency of production of boiled sausages, enriched with flour from the husk of Plantago psyllium L. reaches 4000 RUB per ton of product.

Protein nutritional value of extrusion-cooking defatted lung flour

The nutritional value of lung protein extruded at diverse conditions of feed moisture and process temperatures was determined by biological assay. No dependence of the nutritional quality of the proteins on process temperature was found in the extrusion of lung with 18% moisture content. Samples extruded at this low moisture (18%) presented a significant decrease in cysteine content and low biological value of the protein, although the decrease which has been observed in the chemical scores of total sulphur and other limiting amino acids was not enough to account for the observed decrease in biological value. Supplementation of this extruded protein with its limiting amino acids restored the initially observed nutritional value. Extrusion performed with 30% moisture lung flour protein resulted in a smaller loss of cysteine content after processing and bioassay comparable to non-processed samples or casein. Digestibilities of the lung samples decreased slightly after defatting and were not affected by their subsequent extrusion. In all lung samples digestibility was high, and thus could not explain the observed poor bioavailability of the protein extruded with 18% moisture content. Racemization could have occurred during the extrusion of this low moisture flour.

Oxidation of free methionine and methionine residues in protein involved in the browning reaction of phenolic compounds.

The oxidation of methionine to its sulfoxide, as a possible cause of decrease in the biological value of red clover during drying with aeration, was examined using various model systems, in the presence or absence of polyphenol oxidase. The effects of catalase were also examined. Results indicated hydrogen peroxide as a possible intermediate that directly oxidizes methionine. The methionine oxidation can be one of the causes of the decrease in biological value of red clover during drying, beside the known damage of lysine in the same process.

Protein quality in cereals and pulses

1. Two preceding papers in this series describe the application of microbiological and other in vitro tests in the evaluation of sorghum (Sorghum vulgare Pers.), field beans (Vicia faba L.) and barley, and in assessing the influence of polyethylene glycol (PEG 4000) on the nutritional availability of the methionine. The present paper gives for comparison the results of bioassays on some of the same test samples. Net protein utilization (NPU) in rats was measured by the nitrogen balance method, and N digestibility in chickens by the ileal analysis procedure. 2. In rat tests on sorghum, N in grain of high-tannin varieties was poorly digested. Supplementation of the test diets with 0.1 g PEG 4000/g protein gave a large improvemnet, which was partly offset by an apparent decrease in biological value (BV). With chickens N digestibility was even lower, and was similarly improved with PEG 4000. Treatment of high-tannin grain with ammonia solution was also effective in improving N digestibility. 3. With low-tannin sorghum the amino acid digestibilities were uniformly high and were not affected by addition of PEG to the test diet. With high-tannin sorghums they were low and less uniform, and were much improved by PEG 4000. 4. With field beans, the influence of the seed-coat tannin on protein utilization was much less pronounced than with sorghum. In chickens there was a significant effect (P less than 0.05) of PEG 4000 on N idgestibility in a high-tannin variety. With rats the effect was smaller and not significant. 5. In four samples of barley. N digestibility was high (0.87--0.96) and was not further improved by PEG 4000. The BV of a high-lysine cultivar proved marginally inferior to that of a normal variety. Possible reasons for this are discussed. 6. Over all, the results were closely consistent with those from microbiological tests with Streptococcus zymogenes.

THE NUTRITIVE VALUE OF LEAF PROTEIN CONCENTRATES DETERMINED IN BIOLOGICAL TESTS WITH RATS AND BY MICROBIOLOGICAL METHODS.

AbstractThe biological values and true digestibilities of a number of leaf protein concentrates have been determined by the balance‐sheet method at an 8% level of protein intake on young growing rats. Determinations were made on preparations from the leaves of 14 different species of plants. The effects of several methods of drying the concentrates and of the maturity of the leaves at harvesting were studied. The availability of some essential amino‐acids was determined microbiologically in selected samples; in all of them methionine was less available than in whole egg proteins. The microbiological results were consistent with the biological findings. In general biological values of the proteins in the leaf concentrates were of the order found for good quality plant proteins such as those of legume and cereal seeds and of yeast but true digestibilities were lower. Freeze‐drying, drying by acetone extraction and drying on starch in a current of air proved satisfactory but oven‐drying at 100° caused a significant decrease in biological value and a more marked loss of true digestibility. Biological values and true digestibility increased with the maturity of the leaves at harvesting because of increased availability of methionine. A possible explanation of the results is suggested.