Effect of dietary vitamin E supplementation on the oxidative stability of lipids and proteins in cooked pork

T. Popova*, P. Marinova, M. Ignatova

Institute of Animal Science, 2232 Kostinbrod, Bulgaria

Abstract. The changes in the lipid and protein oxidative stability in m. Longissimus dorsi (m. LD) and m. Semimembranosus (m.SM) in response to vitamin E supplementationinthediet(400mg/kgfeed)andcookingwerestudiedin♀Younax♂Pietrainpigs. Musclesampleswerecookedat100°Cfor30minutes.

Lipid oxidation was analysed by determination of 2-thiobarbituric acid reactive substances (TBARS) and the oxidation of proteins was determined by measuring the content of carbonyls in muscles before and after cooking. Dietary vitamin E supplementation in pigs affected significantly the lipid oxidative stability by reducing the content of TBARS in fresh and cooked samples of m. LD (p<0.01) and m.SM (p<0.001). Protein oxidation was not significantly influenced by vitamin E, although the carbonyl contenttended to be lower in the samples of m. SM in the supplemented pigs. In both muscles oxidative stability was affected by the high temperature showing significantly increased contents of TBARS (p<0.001) and carbonyls in cooked samples, regardless of presence if vitamin E in the diet.

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Influence of the sweet red paper extract on the quality and oxidative changes in fats of sausages

А. Kuzelov1*, V. Ilieva2, N. Taskov3, D. Saneva3

1Department for Food Technology and Processing of Animal Products, Faculty of Agriculture, Krste Misirkov, 2000 Stip, Macedonia 2Department for Crop Production, Faculty of Agriculture, Krste Misirkov, 2000 Stip, Macedonia
3Faculty of Tourism and Business Logistics, Krste Misirkov, 2000 Stip, Macedonia

Abstract. The purpose of this paper is to examine the impact of red sweet peppers extract on the chemical, microbiological and sensory oxidative changes presented through the parameters, acid level and properties, hydrolytic and peroxide number, during the ripening and keeping of sausage type Kulen. For this purpose, five groups of kulen sausages were made (control group I without addition of the extract, group II – 0.1 g/kg, group III – 0.2 g/kg, group IV – 0.3 /kg and group V – 0.4 g/kg extract of sweet peppers). The groups were made according to the rulebook for quality of minced meat, meat preparations and meat products no. 63 from 2013 in Macedonia. After drying and ripening sausages were stored at 4°C. At the beginning, the average initial values of free fatty acids are relatively low (from 0.20 to 0.50%), but during the production (40 day) the content of free fatty acids increased (from 2.20 to 2.50%). During the keeping and storage from 40 to day 75 in group V has the lowest increase in the content of free fatty acids and the highest in group I (2.50% 40 day to 3.78% 75 day). During the ripening, drying and storing of the sausage from day to day 70 in group V the increase in oxidative changes was the lowest (0.58 to 0.72 and from 0.72 on day 40 to 1.12 on day 75) and the highest in group I (0.65 to 1.20 and from 1.20 on day 40 to 2.20 on day75). Although there are no statistically significant differences among the tested samples during the production process and during storage of the sausage (p>0.05) the obtained lower values compared to the oxidative changes in group V are probably the result of antioxidative effect of the extract. Groups IV and V had a good cross section color of the final product compared to the other groups. During the ripening and drying, the extract of sweet pepper has no influence on pH, chemical composition and microbiological status of the final product.

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Egg quality and shell colour characteristics of crosses between Araucana and Schijndelaar with highly productive White Leghorn and Rhode Island Red strains

H. Lukanov1*, A. Genchev1, A. Pavlov2

1Department of Animal Science, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Pharmacology, Animal Physiology and Physiological Chemistry, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria.

Abstract. The experiment was performed with 8 groups of 38-week-old hens (4 control and 4 experimental groups). Control groups comprised purebred White Leghorn, Schijndelaar, Rhode Island Red and Araucana hens used for formation of experimental groups of F1 crosses between White Leghorn х Schijndelaar, White Leghorn х Araucana, Rhode Island Red х Schijndelaar and Rhode Island Red х Araucana. Twenty-four eggs were collected from each group. The aim of the study was to investigate some of the primary egg quality traits and shell colour characteristics in the CIE L*a*b* system. The following parameters were determined: egg weight (g), shape index (%), albumen index, Haugh units, yolk index, yolk colour score (by La Roche scale) and average eggshell thickness (μm). The proportions of the different egg parts were calculated for each of the groups. Higher egg weights were found in breeds selected for this trait (Rhode Island Red and White Leghorn) compared to breeds in which the selection in this direction was not purposeful (Schijndelaar and Araucana) (р<0.001). Egg weight had very weak influence on egg albumen and yolk (<1% of the total dispersion of traits). The shape index of the studied eggs varied from 78.98 in purebred Araucana group to 75.36 in White Leghorn x Araucana crosses. The eggs of Schijndelaar and White Leghorn, as well as of White Leghorn х Schijndelaar and White Leghorn х Araucana crosses had normal oval shape (SI 75.3 – 76.5%), whereas the eggs of purebred Araucana and Rhode Island Red hens as well as their crosses were more oval (SI 77 – 79%). A linear negative relationship between the shape index and yolk proportion was established (L=0.068), with correlation coefficient r =-0.260. Schijndelaar hens exhibited the lowest values of the following traits: egg weight 45.90 g, albumen index 0.05, haugh units 65.13, yolk index 0.405 and yolk colour score 11.58 (p <0.001). Among the studied groups, White Leghorn eggs had the thickest eggshells (445.39 μm), while the Rhode Island Red х Araucana crosses (392.8μm) – the thinnest. The lowest relative albumen proportion was demonstrated in the eggs of Rhode Island Red х Schijndelaar crosses (56.2). The investigation of eggshell colour showed reduction of L* values from 95.49 in white-shelled eggs to 59.71 in brown-shelled eggs (р<0.001). The shell colour index (SCI) was the highest in white eggs (White Leghorn) and in blue-green eggs of Schijndelaar which had comparable colour characteristics. The lowest SCI was established in brown eggs (Rhode Island Red).

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Study of physicochemical parameters of lamb meat from North East Bulgarian fine fleece breed of sheep and its crossbreds from internal breeding

R. Slavov1*, G. Mihaylova1, S. Ribarski2, P. Slavova3, D. Pamukova1

1Department of Animal Science – Ruminants and Dairy Farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Department of Morphology, Physiology and Nutrition, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 3Agricultural Institute, 6000 Stara Zagora, Bulgaria

Abstract. A comparative analysis of physicochemical parameters of meat from lambs of North East Bulgarian fine fleece breed and its 25% crossbreds from internal breeding with heredity from Australian merino breed and Ile de France breed. Upon starting the experiment lambs were equal and during the experiment they were placed under similar conditions of feeding and rearing. To establish the quantitative and qualitative parameters of heredity slaughter analysis were performed at 100 and 130 days of age. From the carcass of each slaughtered animal pooled samples and individual samples from m. Longissimus, m. Semitendinosus and m. Semimembranosus were taken. Studies were carried out in the Research Laboratory of the Faculty of Agriculture at Trakia University. As a result of the study the following conclusions were made: The use of the Ile de France breed in a sophisticated crossing scheme within the North East Bulgarian fine fleece breed and subsequent internal breeding relates primarily to the achievement of the highest content of protein and phospholipids in the meat of crossbred lambs from internal breeding with 25% heredity from Ile de France breed. The highest is the level of protein in all three tested muscles in the same type of crosses. Water retention and pH24 of meat from m. Longissimus, m. Semitendinosus and m. Semimembranosus of 100- and 130-day-old lambs in all three groups of lambs vary within narrow ranges and values give a reason for the meat to be described as having good quality. Internal breeding of crossbreds with 25% heredity from Australian merino breed does not affect adversely the physicochemical parameters of meat.

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Effects of salt-curing on physicochemical and technological properties of Japanese quail breast meat

S. Ribarski1*, H. Lukanov2, I. Penchev3, A. Genchev2, E. Lyutskanova2

1Department of Morphology, Physiology and Nutrition, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Animal Science, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
3Department of Pharmacology, Animal Physiology and Physiological Chemistry, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. The purpose of the study was to establish the physico-chemical and technological properties of salt-cured breast meat from Japanese quails. It was found out that the most dramatic changes occurred during the first 4 h after the slaughter. During that period, the meat temperature decreased almost linearly from 39.8 to 10°С. The values of рН declines between post slaughter min 30 and hour 4 from 6.0 to 5.59 (Р<0,001). The curing of meat with 3% or 1.7% NaCl solutions did not have any effect on water holding capacity. After defrosting of frozen salt-cured meat, the water holding capacity was considerably improved (11 – 12.4%), consequently to loss of water. Japanese quail breast meat cured in salt solutions increased its weight by 7.7 – 8.4% on the average. After cooking, salted breast meat lost about 19 – 25% of its weight. During the first 24 h after the slaughter, L*a*b* values of m. Pectoralis increased. Within this period, lightness increased almost linearly from 41.28 to 45.51 at an increment ΔL * during the first post slaughter half an hour of 5.38 (Р<0.01) and ΔL* of 5.21 between min 30 and hour 4 (Р<0.05). Most substantial changes occurred in colour coordinates а* and b* between the 4th and 24th post slaughter hours, when they increased by 16.5 to 19.7%. Salt-curing increased significantly the values of L* and b*. The a* value was reduced (Р<0.001). The analysis of L*a*b* values of salt-cured breast meat from Japanese quails did not take into consideration the effect of salt solution concentration. The meat colour index (MCI) however demonstrated that salt-curing resulted in lightening of meat samples with influence of salt solution concentration. The curing of m. Pectoralis with 3% NaCl increased the colour index by 19.5% (Р<0.001), while curing in 1.7% NaCl resulted in considerably lighter meat – 58.6% (P<0.01).

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Chemical and physical properties of the Albic luvisols from Albota-Pitești

M. Mihalache1*, L. Ilie1, M. Todorova2, N. Grozeva2

1Faculty of Agriculture, University of Agronomic Sciences and Veterinary Medicine, Bucharest, Romania 2Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. Luvisols extend over 500 to 600 million hectares world-wide, for the greater part in temperate regions such as west/central Russia, the USA and Europe but also in the Mediterranean and in Southern Australia WRBSR (1998). In Romania, Luvisols occupy an area of over 4.2 million hectares. Luvisols are characterized with a textural contrast between A and B horizon – the Ea horizon has less clay than the Bt horizon. This difference in clay content between the two horizons is due to the physical transfer of clay (termed lessivage) from the Ea (eluvial) to the Bt (illuvial) horizon by vertically draining soil water. The aim of theresearchwastoidentifythemainlimitingfactorsofAlbicluvisols fromtheNorthRomanianPlainareaforagriculturalproduction.Physicalandchemical parameters of soil in the studied area were determined. The analysis has identified a number of negative factors which require the application of measures for improvement.Forinstance:highclaycontent,veryacidicsoilreaction,low nutrientavailabilityduetohighaluminumcontent,lowtotalporosityandverylow permeabilitytowateroftenleadstostagnationofwateronthesurfaceinslightlydepressionareas.Albicluvisols fromtheNorthRomanianPlainareaare characterized with low fertility and require urgent improvement measures.

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Groundwater quality as a source for irrigation in Strumica valley, Republic of Macedonia

B. Kovacevik*, S. Mitrev, B. Boev, I. Karov, V. Zajkova Panova
Laboratory for Plant Protection and Environment, Goce Delcev University of Stip, Krste Misirkov, 2000 Stip, Republic of Macedonia

Abstract. The quality of groundwater was investigated for possible agriculture pollution in the traditional agriculture region of Strumica, situated in the southeast part of the Republic of Macedonia. Almost 200 samples of water from boreholes in 14 different points were collected and analyzed by relevant standard methods for a total content of Na+, K+, Ca2+, Mg2+, NH +, Cl-, HCO -, SO 2-, NO -, NO -, and PO 3-. The results showed that groundwater in the studied area is generally neutral to slightly alkaline. The abundance of the major ions is Mg2+>Ca2+>K+>Na+ and HCO ->Cl->PO 3->SO 2-. Concentration range of the main 344 cations Na+, K+, Ca2+ Mg2+ and NH + is 1.40 – 36.71mg/L, 0.68 – 354.44 mg/L, 7.43 – 411.18 mg/L, 1.07 – 96.14 mg/L and < LOQ (limit of quantification) – 55.89 4 mg/L, respectively. Regarding anions Cl-, HCO -, SO 2-, NO -, NO -, and PO 3- concentration range is 4.19 – 614.31mg/L, 0.04 – 750.97 mg/L, < LOQ – 300.45 34324 mg/L 0.14 – 284.44 mg/L, < LOQ – 35.85 mg/L and < LOQ – 7.80 mg/L, respectively. A multivariate statistical analysis is performed to evaluate the possible interrelationship within a set of variables. Statistical and hydrochemical analysis suggest that the quality of groundwater is mainly affected by the geological composition of the area. Factor analysis (FA) revealed five significant factors of 14 variables and account for 71.54 % of the total variance. Although nitrates are considered a significant source of widespread groundwater contamination, when it comes to agricultural areas the result didn’t show any severe contamination except in the periphery of the valley which is considered to be related to the thickness of the basal lithozone represented by sandstones and the shallow aquifers.

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Visible – NIR reflectance for evaluation of luvisols and phaeozems

M. Todorova1*, M. Mihalache2, L. Ilie2, S. Atanassova3

1Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Faculty of Agriculture, University of Agronomic Sciences and Veterinary Medicine, Bucharest, Romania
3Department of Biochemistry, Microbiology and Physics, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. Near infrared spectra of soils with differences in soil colour, organic matter and clay mineral content showed differences in the spectral region from 700 to 1700 nm. The objective of the present study was to describe the information content of soil vis-NIR spectra of two soil types Luvisols and Phaeozems from Romania to assist soil surveys. The samples were collected from each horizon of the soil profiles. The diffuse reflectance spectra of the air-dried and sieved soil samples were obtained using both spectrophotometers – USB 4000 (OceanOptics, Inc.) into spectral range 450 – 1100 nm and NIRQuest (OceanOptics, Inc.) into spectral range 900 – 1700 nm. The diffuse reflectance, R, was transformed to absorbance using log (1/R). All of these samples have location information and a set of soil chemical and physical analytical data. Similarities and differences in absorption maxima of soil spectra from the different soil taxonomic classes using 2nd derivative of raw spectra are discussed. Principal Component Analysis (PCA) and SIMCA – soft independent modeling of class analogy was used for qualitative analysis. The obtained results showed that specific differences in Vs-NIR spectral data of Luvisols and Phaeozems from Romania existed. These spectral data could be used to develop models for soil discrimination according to soil taxonomic classes.

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Chromium level in water, sediment, aquatic plants and meat of common carp (Cyprinus carpio L.) from different water bodies in Bulgaria

E. Valkova1*, V. Atanasov1, K. Velichkova2, G. Kostadinova3, M. Tzanova1

1Department of Biochemistry, Microbiology and Physics, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Department of Biology and Aquaculture; Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
3Department of Applied Ecology and Animal Hygiene, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. Chromium (Cr) is heavy metal often found in aquatic ecosystems due to its widespread use in households and industry. Reaching toxic levels in water, chromium may cause a violation of many metabolic processes in hydrobionts. The aim of the present study was to investigate and assess the Cr concentration levels in water, sediment, aquatic plants and meat of common carp from different surface water bodies in a region of Bulgaria with high anthropogenic impact. International standards of ISO and BSS for sample preparation of water, sediment, aquatic plants and meat of common carp analysis were used. Concentration of Cr in the analyzed samples was determined by atomic adsorption spectrometry. It was found that the Cr levels: a) in surface water varied from 0.012 mg/l in monitoring point (MP-5) to 0.043 mg/l in MP-6, all concentrations exceeded the maximum admissible concentration (MCA) – 8 μg/l (0.008 mg/l) for Cr (VI) according to Regulation No 4-H (2012) for characterization of surface water, from 1.5 times in MP 5 to 5.38 times in MP 6; b) in sediment ranged from 20.7 mg/kg in MP 1 to 199.9 mg/kg in MP 4, which are lower than the MCA for cultivated soil – 200 mg/kg dry soil according to Regulation No 3/01.08.2008 concerning norms for admissible content of harmful substances in the soil, from 1 time in MP 4 to 9.6 times in MP 1; c) in aquatic plants varied from 6.021 mg/kg in MP 3 to 23.2 mg/kg in MP 6; d) in common carp meat were between 0.11 mg/kg in MP 5 and 0,16 mg/kg in MP 3, which is lower than the MCA (0.3 mg/kg) for maximum permissible quantities for contaminants in food (Regulation No 31, 2004), from 0,37 times in MP 5 to 0.53 times in MP 3. Cr accumulation was not observed in the tested common carp meat samples, which most probably is due to its accumulation in organs with active metabolism (gills, liver); e) proportions of accumulation of Cr in the trophic chain are different for the different units – water/sediment (1040 – 12 129 times more), aquatic plants/water (207 – 1011 times more) and meat of common carp/water (9.1 – 12.1 times more).

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Changes in the productivity and the yield structural elements in some spring crops sown on damaged by frost crops of winter oilseed canola

G. Delchev*

Department of Plant Production, Faculty of Agriculture, Trakia University, 6000, Stara Zagora, Bulgaria

Abstract. During 2010 – 2012 a field experiment was conducted. Eight hybrids of winter oilseed canola (Brassica napus L.) were investigated: 2 ClearField hybrids – PT200CL and Sunset; 1 ClearField Maximus hybrid – PX100CL; 4 conventional hybrids – PT205, Rohan, Exagon and Nelson; 1 conventional Maximus hybrid – PR44D06. On fields with damaged by frost winter canola in spring were sown and investigated: 2 conventional hybrids spring oilseed canola – Zhura and Williams; 1 cultivar of durum wheat (Triticum durum Desf.) – Elbrus; 3 hybrids oil-bearing sunflower (Helianthus annuus L.): 1 conventional hybrid – Arena, 1 ClearField hybrid – Allego and 1 ExpressSun hybrid – P64LE20; 2 hybrids grain maize (Zea mays L.): 1 cool resistance conventional hybrid – Novatop and 1 Duo System hybrid – Blason duo; 1 hybrid grain sorghum (Sorghum bicolor Moench.) – Alise.

Seed yield of spring oilseed canola hybrids Zhura and Williams with optimal sowing densities are lower than the yields of winter hybrids Exagon and Nelson with minimum sowing densities. Changes in the seed yield of oilseed canola due to changes in number of seeds per pod, seed weight per pod and 1000 seeds weight. After plowing of fields with damaged by frost winter canola hybrids spring durum wheat should not be planted. Changes in the grain yield of durum wheat are due to changes in number of grains per spike, grain weight per spike, and 1000 grains weight. After plowing canola crops it is appropriate to sow imitolerant or tribenulon-methyl tolerant sunflower hybrids instead of conventional sunflower hybrids. Changes in the seed yield of oil-bearing sunflower are due to changes in number of seeds per head, seed weight per head and 1000 seeds weight. After plowing of canola, more weeded fields should be sown with cycloxydim tolerance maize hybrids and less weeded fields – with conventional maize hybrids. Changes in the grain yield of maize are due to changes in number of grains per cob, grain weight per cob, and 1000 grains weight. Grain sorghum grown by Concept technology is a suitable crop for sowing on fields after damaged by frost winter canola. Changes in the grain yield of sorghum are due to changes in number of grains per panicle, grain weight per panicle, and 1000 grains weight.

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