FATTY ACID CONTENT OF YOGURT PRODUCED FROM THE MILK OF SHEEP REARED IN CENTRAL BALKAN MOUNTAINS

Gercho GERCHEV, Gyurga MIHAYLOVA

Abstract. The study was performed on bulk milk samples obtained monthly during the milking period from the Srednostaroplaninska and Teteven sheep breeds, reared on pasture in the region of Central Balkan mountains. The technological part of yogurt production was carried out at the laboratory. Extraction of fat from the milk samples was done per the Rose-Gottlieb method. The fatty acid content was established on a gas chromatograph with a flame-ionisation detector and a capillary column. Saturated fatty acids in the milk of Srednostaroplaninska and Teteven sheep had a relatively high content during the milking period – 71.793% and 70.698%, respectively, with myristic acid content of 10.778% and 10.873%, respectively. The total amount of polyunsaturated fatty acids in the examined milk was relatively low and with similar concentrations (4.145-4.437%) during the months of the grazing period. Monounsaturated acids were mostly represented by oleic acid (С18:1), and its values in the milk of Srednostaroplaninska and Teteven sheep was, respectively, 23.545% and 25.271%. No significant change in the content of fatty acids could be observed over the course of yogurt production, in comparison with raw sheep milk.

Key words: sheep milk, yogurt, fatty acids

MORAVA – THE FIRST BULGARIAN STANDARD WHEATGRASS VARIETY [AGROPYRON DESERTORUM (FISCH.) SCHULTES]

Anelia KATOVA

Abstract. The first Bulgarian and European standard wheatgrass variety Morava – tetraploid, high productive, ecologically stable (winter hardy and drought resistant), resistant to leaves diseases and exceptionally long-lived and persistent had been developed during the period 1995 – 2010 in the Institute of Forage Crops – Pleven. Recurrent phenotypic selection, vegetative propagation (clones selection) of 15 elite genotypes with local origin from Northeastern Bulgaria and polycross methods were applied to its creation. The variety is multifunctional, suitable for hay, hay-pasture use, for erosion control and landscape maintaining. It can be component of hay mixtures with alfalfa and sainfoin. The results from successful competitive varietal test trial (CVT) in Pleven (2001-2004 г. average DMY 9615 kg ha -1) and from National official varieties testing trials for Value of Cultivation and Use (VCU average DMY 10021 kg ha -1) from three locations (Chepinci, Plovdiv and Selanovci) and for Distinctness, Uniformity and Stability (DUS) in one location (Chepinci) of the Executive Agency for Variety Testing, Field Inspection and Seed Control (EAVTFISC) (2006 – 2008 г.) are presented and the description of the variety Morava. The variety have been registered on the Official Variety List of the Republic of Bulgaria (OVL) for the years 2012, on OECD list for the year 2010, 2011 and 2012 г., with Certificate from the Patent Office of the Republic of Bulgaria from 2010.

Key words: Standard wheatgrass, new variety, description, CVT, VCU, DUS

BIOCHEMICAL CHARACTERIZATION OF SPECIES AND POPULATIONS BIRDSFOOT TREFOIL (LOTUS CORNICULATUS L.) GROWN IN THE REGION OF TROYAN

Boriana Georgieva CHURKOVA

 Abstract. During the period 2005-2007 in the field experiment were tested local populations birdsfoot trefoil originate from Troyan and Staro Selo and introduced varieties Bosna (Yugoslavia), Tana (USA); Ergeshi (Hungary); Pekoli (Hungary), Gjiki (Hungary) on agri-environmental conditions of Troyan. The objectives was analyzed plant samples taken immediately before harvest any undergrowth in Weende method. For received data was used variational-statistical method and the correlation analysis. The variety Ergeshi was with high crude protein content (18.14%), variety Tana– the low amount of crude fiber (26.94%) and variety Bosna – the high percentage of calcium (1.77%). They can be used as genplazma in further breeding work. The differences between samples of different origins in calcium content were negligible. Astrong degree correlation between calcium content and yield of dry weight, was established (r = 0.64951). and low between phosphorus content and percentage contribution of leaves (r = 0.45805).

Key words: birdsfoot trefoil (Lotus corniculatus L.), variety, populations, chemical contens, statistical analysis

CONFIDENCE BAND APPROXIMATION USING INTERVAL ARITHMETIC

Simon BROWN, Kevin C. PEDLEY, Noorzaid MUHAMAD, David C. SIMCOCK

 Abstract. Confidence bands are commonly obtained from linear regression, but they are rarely shown for nonlinear functions. In part this is due to mathematical complexity. A simple, intuitive and easily automated alternative is to employ interval arithmetic to approximate the confidence band. We illustrate the method by applying it to a straight line, and then apply it to the rate equation of a Michaelis-Menten enzyme and a general polynomial. In each case the approximation is generally larger (and never smaller) than the corresponding standard confidence band, but in at least some instances the upper bound of the discrepancy is about 40%.

Keywords: confidence interval, interval arithmetic, Michaelis-Menten kinetics, polynomial.


BIOMETRIC PERFORMANCE AND PRODUCTIVITY OF VARIETIES AND LOCAL POPULATIONS BIRDSFOOT TREFOIL UNDER THE SOIL AND CLIMATIC CONDITIONS OF TROYAN

Boryana CHURKOVA

Abstract. For determination of the plant height, number of main stems and productivity of varieties and populations birdsfoot trefoil a field experiment was carried out during 2008-2010 period in RIMSA – Troyan. Objects of study were the populations originating from: Shumen, Nesebar, Kiten, Tryavna, Sadovo, as well as genotypes of the varieties: V. Podolyanskii (Russia), Dedinovskii (Russia), Martanskii (Russia), Zora (Serbia), Bokor (Serbia), Smolenskii (Russia). Variety Targovishte 1 (St) was used for comparison. The aim of this study is was to investigate the biometric and quantitative indicators of birdsfoot trefoil varieties and populations under agro-ecological conditions of Troyan. The highest forage productivity was obtained in variety Dedinovskii, under the soil and climatic conditions of Troyan. The variety was characterized by high stems and the highest number of main stems. The populations originating Nesebar and Kiten also realize high productivity. The lowest productive was obtained in the variety Zora, due to its poor adaptability to specific soil conditions and lower its productive potential. The third year of the experimental period was characterized by rather high productivity of all studied accessions. The average height of all varieties and populations was 25.4 cm, with minimum and maximum 22.5 cm 29.2 cm. According to the variation coefficient values of the indicator stem height (CV=6.73%) was set very low variability. Average for the period of the investigation the values for the number of main stems varied from 23.7 to 44.0 and their maximum was observed in a variety Dedinovskii (44.0), Martanskii (37.7) and population Nesebar (37.0). The higher density of these accessions and explains their higher productivity.

Key words: birdsfoot trefoil, varieties and populations, plant height, number of main stems, productivity

DYNAMICS OF FORAGE BIOMASS ACCUMULATION IN MAIN PHENOPHASES OF A NATURAL MEADOW OF AGROSTIS CAPILLARISFESTUCA FALLAX TYPE IN THE RHODOPE MOUNTAINS (BULGARIA)

Yanko KOZHOUHAROV, Vladimir LINGORSKI

Abstract. The purpose of this study was to establish the changes in biomass productivity and forage chemical composition in main phenophases of vegetation period of a natural meadow Agrostis capillaris-Festuca fallax type in the Rhodope Mountains (Smolyan region, Southern Bulgaria). The greatest dry mass yields (2.91 and 2.68 t.ha-1) were obtained after annually fertilization with N160P80 and N80P80. With advance of vegetation (from complete stalk shooting to complete flowering) was established a decreasing of the crude protein, crude fat and crude ash contents, while in the crude fiber and nitrogen-free extract substances (NFES) was reported an increasing. The most crude protein production was obtained after fertilization with N160P80 (0.89 t.ha-1), and at least in the unfertilized control (only 0.33 t.ha-1). The most feed units (FU) per 1 ha also were reported in fertilization-use N160P80 (2184.33 FU) and N80P80 (1892.00 FU).

Key words: natural meadow, phenophase, biomass accumulation, chemical indicators, the Rhodope Mountains.

DYNAMICS OF FORAGE BIOMASS ACCUMULATION IN DECADES OF A NATURAL MEADOW OF AGROSTIS CAPILLARIS-FESTUCA FALLAX TYPE IN THE RHODOPE MOUNTAINS

Yanko KOZHOUHAROV, Vladimir LINGORSKI

 Abstract. The purpose of this study was to establish the changes in productivity and chemical composition of forage biomass in decades of vegetation period of a natural meadow Agrostis capillaris-Festuca fallax type in the Rhodope Mountains (Smolyan region, Southern Bulgaria). The productive potential of the grass stand was dependent on age of the grasses and the level of mineral fertilization. The greatest yields were obtained after fertilization – 3.92 t.ha-1 (N160P80) and 3.68 t.ha-1 (N80P80). Most crude protein (320-325 g.kg-1 dry matter) contained the forage at the beginning of grass vegetation, while in the same period the crude fiber were at least. It was observed an opposite dependence with advance of vegetation. With the same period, the crude fat content decreased significantly but this reduction was greater in unfertilized control. Nitrogen-free extract substances content increased with the age of grasses and decreased with increasing of mineral fertilization levels. This chemical indicator varied from 350 g.kg-1 dry matter after N160P80-fertilization to 370 g.kg-1 in control. The advance of vegetation had a negative effect on the crude ash content as at the end of vegetation period it decreased almost 3 times. The crude ash values varied in small limits – from 81 g.kg-1 dry matter (N160P80) to 90 g.kg-1 (in unfertilized control). The greatest values of the crude protein yields were reported between 71st–92nd day (from 91.9 to 97.0 t.ha-1) after N80P80-and between 71st–102nd day (from 105.9 to 110.5 t.ha-1) after N160P80-fertilization. Most feed units per 1 ha were obtained after fertilization with N160P80 – 2509.4 FU and with N80P80 – 2225.5 FU.

Key words: natural meadow, forage biomass, decade accumulation, indicators, the Rhodope Mountains (Southern Bulgaria).

VACUUM FRYING: AN ALTERNATIVE TO OBTAIN HIGH QUALITY POTATO CHIPS AND FRIED OIL

AMANY, M. M. BASUNY, SHAKER, M. ARAFAT, AZZA, A. A. AHMED

Abstract. The purpose of this work was to study the effect of different frying process (atmospheric and vacuum) on some physical and sensory properties of potato chips and to evaluate frying oil quality. In six consecutive days, sunflower oil was fried under atmospheric condition (at 180°C± 5°C and vacuum frying (at 120°C, 5.37kpa absolute pressure) for 20 min each hour in a 4 hour shift. Physical properties (oil uptake and moisture content), Organoleptic tests were performed on fried potato chips and quality limits (acid value, peroxide value, polar content, polymer content and oxidized fatty acids) of the sunflower oil samples were measured. The results of this study suggest that vacuum frying at 120°C under pressure of 5.37kpa night produce potato chips with acceptable quality and improved quality of frying oil.

Key words: Vacuum frying oil uptake, sensory properties, oxidative stability.

FUNDAMENTALS OF ISOTHERMAL TITRATION CALORIMETRY AND SOME APPLICATIONS

Steliana RODINO, Marian BUTU, Diana GOLEA, Alina BUTU

Abstract. Very high affinity and very low affinity processes cannot be studied by standard protocols. Binding involving very small heat changes cannot be detected and sometimes, the large amounts of material required for accurate measurements make standard protocols impractical. Isothermal titration calorimetry (ITC) has become a gold standard in determining the binding energies and the data provided by ITC can be used as reference data by simulation and prediction methods of the thermodynamic variables. In this paper we will discuss the fundamental process of calorimetry, including a short history of isothermal titration calorimetry, a short description of the method and some applications of this technique.

Keywords: calorimetry, interactions, binding affinity, isothermal titration calorimetry

EVALUATION OF ANTIOXIDANT EFFECT OF RIBES NIGRUM AND VACCINIUM MYRTILLUS LEAVES EXTRACTS ON LIPID OXIDATION

Diana GOLEA, Marian BUTU, Steliana RODINO, Alina BUTU

 Abstract. One of the major concerns of phytotherapy is enhancement of the new sources of raw materials rich in active principles. Research in this field are considering as inexhaustible the sources and performances of plant materials provided by nature. The subject of this study fits the current trend of development of the biotechnologies that have an impact on maintaining and improving the quality of life. This represents a topic of general interest through the subject approached, namely: research regarding the protective role of flavone compounds to prevent and “stop” the lipids oxidation due to free radical attack. The aim of this research was to evaluate, by comparison, the antioxidant potential of two extracts, obtained from Ribes Nigrum and Vaccinium Myrtillus leaves, on lipid oxidation from artificial membranes.

Key words: Ribes Nigrum, Vaccinium Myrtillus, liposomes oxidation