Authors:Éva Szabó, R. Romvári, Hedvig Fébel, and et al.
The present study was designed to investigate whether meat-type rabbits are able to perform treadmill running as a daily routine exercise, and if so, whether the exercise induces specific proportional changes in the fatty acid composition of their muscles. After a four-week training period 8-week-old rabbits were slaughtered and the total activity of plasma lactate dehydrogenase was measured, showing a significant difference between the exercised and control groups (429 ± 126 IU/l vs. 639 ± 203 IU/l). Furthermore the fatty acid composition of m. longissimus dorsi (MLD) and m. vastus lateralis (MVL) was determined by means of gas chromatography. Exercise increased the proportions of oleic acid (C18:1 n-9) in both MLD and MVL as compared to the control group. However, the level of stearic (C18:0) and arachidonic (C20:4 n-6) acids significantly decreased in the MVL after the exercise. Changes in the fatty acid profile resulting from the physically loaded condition were of the same tendency in both muscles, adding that the MVL might have been exposed to the exercise more intensively; alterations there occurred in a more pronounced manner. Based on the inference that the composition of membrane structure was also affected, these alterations may have important consequences on meat quality.
Authors:Éva Szabó, R. Romvári, P. Bogner, Hedvig Fébel, and Zs. Szendr'
Pannon White growing rabbits (a group of 8) were exposed to treadmill exercise (3-9 m/s, 1.2-1.6 km/day) twice a day for 4 weeks, while additional 8 animals, kept inactive, were assigned as the control group. Weekly, 12 hours after exercise, venous blood was taken for serum metabolite and enzyme activity measurements. Total serum protein, albumin and creatinine levels significantly increased during the second half of the training, as compared to the control group. Triacylglycerol levels in the exercised group as compared to controls, however, were higher only after the first and the fourth weeks of the experiment. Resting non-esterified fatty acid (NEFA) concentration of the trained rabbits was lower at the end of the trial. On the other hand, there were no significant differences, as compared to the respective controls, in serum urea, total and HDL cholesterol levels. At the end of the exercise alkaline phosphatase activity was higher and total lactate dehydrogenase activity was lower in the trained rabbits. Serum alanine aminotransferase, aspartate aminotransferase and γ-glutamyl transpeptidase activities were not changed, while creatine kinase activity was slightly lower in the trained group. The serum cortisol concentration was not different in the trained and control rabbits.
Authors:J. Belovai, R. Romvári, H. Fébel, A. Szabó, and D. Bánáti
The n-3 fatty acids advantageously affect human health. Thus, partial substitution of pig backfat with soybean- or flaxseed oils in “Párizsi” (lyoner), with the aim to increase its n-3 fatty acid (FA) content, resulted improved FA profile (n-6/n-3 ratio). Relatively high (9% flaxseed oil) substitution decreased this ratio to the optimum (∼4). This modified FA profile was preserved during 32 storage days. Oil addition influenced fresh surface colour: lightness (L*) increased, redness (a*) decreased in parallel with the increasing oil addition, while only soybean oil increased yellowness (b*). Storage altered the colour slightly. The texture was not systematically altered by oil substitution, while during storage in a vapour permeable casing hardness increased. Considering organoleptic properties, soybean oil improved the extent of spiciness, while the general consumer acceptance was the most favourable (within complemented samples) by 3% flaxseed oil. Increasing vegetable oil levels intensified the taste of spice mixture.
Authors:É. Varga-Visi, B. Toxanbayeva, G. Andrássyné Baka, and R. Romvári
The fat content of Bologna-type turkey sausages was partially replaced with pea fiber or potato starch. Textural properties of full fat turkey sausage were mainly restored in sausages when fat was partially replaced with some levels of pea fiber (0.6, 1.2%) or potato starch (1.9%). Authors observed significant correlation (P<0.01) between instrumentally measured values of hardness and chewiness and sensory ratings of low fat sausages.
Authors:L. Locsmándi, G. Kövér, G. Bázár, A. Szabó, and R. Romvári
The feasibility of NIR spectroscopy for
determining chemical composition of goose fatty liver was studied. The spectra
of 50 fresh, homogenized liver samples (ether extract content EE=53.2,
SD=4.87%) were taken between 1100 and 2500 nm in reflectance mode, then the
chemical composition and the fatty acid profile was measured (gas
chromatography). Calibration equations were developed using modified partial
least-squares regression. The R
value in estimation of DM, CP and total EE were 0.72, 0.63 and 0.81,
respectively. For the major fatty acids (oleic, palmitic and stearic acid,
51.4, 25.8 and 15.5% of total) the R² values were 0.94, 0.93 and 0.16. The
estimation of the total saturated fatty acid (SAT) proportion and the so-called
unsaturation index (UI) value was effective (R
=0.81 and 0.79, respectively).
The paper demonstrates the usefulness of the NIRS method as a fast and solvent
free alternative of liver qualification. For practical purposes a larger number
of fatty liver samples are needed.
Authors:Zs. Petrási, R. Romvári, G. Bajzik, B. Fenyves, I. Repa, and P. Horn
A dynamic magnetic resonance imaging (MRI) method was developed for in vivo examination of the pig heart. Measurements were carried out on 15 meat-type pigs of different liveweight using a 1.5 T equipment. Inhalation anaesthesia was applied, then data acquisition was synchronised by ECG gating. Depending on the heart rate and heart size, in each case 8 to 10 slices and in each slice 8 to 14 phases were acquired prospectively according to one heart cycle. During the post-processing of the images the left and the right ventricular volumes were determined. The values measured at 106 kg liveweight are 2.5 times higher than those obtained at 22 kg, while the ejection fractions are equal. The calculated cardiac output values were 3.5 l (22 kg, 132 beats/min.), and 6.0 l (106 kg, 91 beats/min.), respectively. After measuring the wall thickness, the contraction values were also determined for the septum (70%), and for the anterior (61%), posterior (41%) and lateral (54%) walls of the left ventricle. Three-dimensional animated models of the ventricles were constructed. Based on the investigations performed, the preconditioning, the anaesthetic procedure, the specific details of ECG measurement and the correct MR imaging technique were worked out.
Authors:L. Locsmándi, G. Hegedüs, G. Andrássy-Baka, F. Bogenfürst, and R. Romvári
A follow-up study was performed to describe characteristic physiological alterations by means of computer tomography, direct chemical analysis and histology of the liver, and blood biochemical parameters during conventional force-feeding of Landes geese. 30 birds were exposed to an 18-day long force-feeding. Sampling was performed at the start and during force-feeding (7th, 11th, 14th, 18th days). Computer tomographic data were plotted in 3D histograms, effectively indicating the volumetric development and the fat deposition of the liver. Applying the so-called fat index, a saturation process was found for the hepatic fat content. Histological sections indicated the appearance of microvesicular fat forms in the hepatocyte cytoplasm, which first turned to a total fatty infiltration, later changing to a macrovesicular form with progressing inflammation; membrane damage was not visualized. In blood metabolites triglyceride, total and HDL cholesterol and uric acid increased measurably, while creatinine concentration decreased. Alanine aminotransferase, aspartate aminotransferase activities increased strongly, while that of lactate dehydrogenase only slightly. Based on the results of macroscopic and microscopic imaging techniques and blood biochemical parameters, a comprehensive follow-up study was performed, elucidating still unknown processes during force-feeding of geese.
Authors:T. Müller, T. Molnár, Éva Szabó, R. Romvári, Cs. Hancz, M. Bercsényi, and P. Horn
Female European eels were kept in artificial seawater for a trial period of 14 weeks. Three fish were injected intra-abdominally with carp pituitary suspension (twice a week) and human chorionic gonadotropin (every 2nd week), with the aim to induce artificial maturation. Three further fish were not treated (control). Fish were not fed during the trial. The treated fish were scanned by computed tomography (CT) every second week (the controls only at the start and at the end of the trial) to follow changes in body composition. Notable decreases were shown in total body pixel number (body volume), total body fat content, total fillet volume and fillet fat content during the experiment. Changes were more pronounced in the treated group than in the control. The abdominal volume strongly increased in the responding fish throughout the trial. The ovary volume increased measurably, while its fat content increased only until the 8th week, after which a decrease was measured. Tissue volumetric estimations of the ovary were also supported by histological results. A so-called volumetric gonadosomatic index (gonad volume/total body volume × 100) was developed for the quantitative characterisation of eel maturation.
Authors:R. Romvári, A. Szabó, J. Kárpáti, G. Kovach, G. Bázár, and P. Horn
The belly region composition of a representative commercial pig sample of 130 castrates was examined by in vivo spiral computed tomographic (CT) scanning. The lean meat percentage, the muscle/fat tissue ratio within the total body and separately within the bacon part were estimated by image analysis. The lean meat content of the total body was determined by the EU reference method. A correlation of r = 0.97 was found between lean meat content of the total body determined by CT estimation and the slaughtering results. The pigs were divided into seven groups on the basis of their lean meat content. The muscle percentage of the bacon part was 26% and 67%, respectively, in the two groups representing the two extremes of lean meat percentage (36% and 67%, respectively). The total volume of the bacon part was relatively constant (8.6 ± 1 dm3) in the groups representing different lean meat categories. At the same time, the fat tissue volume of the bacon part was considerably higher while its muscle tissue volume was markedly lower in the group of the lowest than in that of the highest lean meat content (6.6 vs. 2.5 dm3 and 2.4 vs. 5.5 dm3, respectively). To describe changes in the tissue composition of the bacon part during fattening, 10 castrates were scanned repeatedly at 70, 90 and 110 kg of liveweight. A linear regression model was developed to characterise the continuous decrease observed in the muscle/fat ratio within the bacon part due to increasing liveweight.
Authors:T. Magyar, F. Kovács, T. Donkó, H. Bíró, R. Romvári, Melinda Kovács, and I. Repa
Computed tomography (CT), a non-invasive visualisation technique was applied for imaging the bony structures of the nasal cavity of pigs, and compared to the traditional scoring system of turbinate atrophy in swine. Twenty-three 27-week-old pigs representing various stages of turbinate atrophy were used. Nasal structures were visually scored on CT scans and transversal cuts of the noses at the level of the first upper premolar teeth using the same scoring system in both cases. A tissue/air area ratio was also determined based on density differences. A highly significant correlation was found between visual scoring of CT images and transversal cuts of pig noses (r = 0.98, p < 0.0001) as well as between visual scoring of CT images and tissue/air area ratio determination (r = -0.82, p < 0.0001).