Authors:J. Schmidt, F. Husvéth, J. Sipőcz, T. Tóth and J. Fábián
Ten Holstein cows between 8 and 12 weeks in lactation were used to investigate the effect of feeding full-fat soybean, full-fat sunflower, and a Ca-soap source (Profat) on the conjugated linoleic acid (CLA) content of milk. Cows were fed the experimental fat sources in the dosage of 500 g crude fat daily. The results indicated that milk CLA content increased in relation to the linoleic acid concentration of experimental fat supplements, namely full-fat sunflower increased the most and Profat increased the least the CLA concentration in milk. The strength of the correlation was r=0.62 between the linoleic acid concentration in feed and the CLA content in milk. The strength of correlation increased to r=0.69 when both linoleic acid and linolenic acid concentration of feed were used in the calculation. Considering milk production and the daily production of CLA in milk, the following equation described the relationship between the linoleic acid content of fat supplements and CLA concentration in milk: x=167.52+0.483×y; where x=CLA mg l
milk and y=linoleic+linolenic acid content of fat sources, g/day. Along with milk CLA, the
-C18:1 concentration of milk also increased, but the magnitude of the increase was smaller compared to that of milk CLA.
This paper reports on the results obtained with the pulsed nuclear magnetic resonance (P-NMR) technique applied for determining fat content in fresh meat. The interfering moisture content of meat was removed by microwave drying and the dried residue was quantitatively transferred into the P-NMR tubes. The total analysis time was about 50 min. Experiments were performed with rendered pure pork, beef and goose fats, sunflower oil and with lean pork - fat and lean beef - tallow mixtures (batters). The regression (prediction) equations (intensity of P-NMR signal vs. fat content determined with the Soxhlet reference method) of the sunflower oil and fat samples did not differ appreciably. Consequently, contrary to the results obtained with the CW-NMR technique, the variability of the fatty acid composition of the examined fats and oil had no substantial effect on the regression (prediction) equations in this case. On the other hand, there was a considerable difference between the regression lines of the lean pork-fat and lean beef-tallow mixtures. Therefore, due to the interfering effect of the non-fat dry matter and the type of meat on the intensity of P-NMR signal, this technique can only have a restricted practical application in the in-line process control of fat content of meats.
This work presents a study of the thermal decomposition of commercial vegetable oils and of some of their thermal properties
by termogravimetry (TG), derivative termogravimetry (DTG) and by differential thermal analysis (DTA). Canola, sunflower, corn,
olive and soybean oils were studied. A simultaneous SDT 2960 TG/DTA from TA Instruments was used, with a heating rate of 10
K min-1 from 30 to 700C. A flow of 100 mL min-1 of air as the purge gas was used in order to burnout the oils during analysis to estimate their heat of combustion. From
the extrapolated decomposition onset temperatures obtained from TG curves, it can be seen that corn oil presents the highest
thermal stability (306C), followed by the sunflower one (304C). Olive oil presents the lowest one (288C). The heat of combustion
of each oil was estimated from DTA curves, showing the highest value for the olive oil. Except for corn oil, which presents
a significantly different thermal decomposition behavior than the other oils, a perfect linear correlation is observed, with
negative slope, between the heat of combustion of an oil and its respective extrapolated onset temperature of decomposition
Authors:J. Kutasi, Á. Bata, E. Brydl, P. Rafai and V. Jurkovich
This paper describes the production of an enzyme preparation from the fungus Thermomyces lanuginosus. Thermal resistance, pH stability and lignocellulolytic activity of the enzyme preparation high in xylanase were studied on a variety of grains and forages. The enzyme preparation preserved more than 70% of its original xylanase activity for 4 and 1 h at 60 and 70 °C, respectively. The xylanase activity remained over 80% when the preparation was incubated for 30 min at pH 4.5. In vitro digestibility studies indicated that the enzyme digested 7.5, 8.5 and 8.0% of the dry matter (DM) of barley meal, wheat bran and oat meal samples, respectively. When applying 60-min incubation, 7.5, 7.3 and 8.4% of DM of the oat straw, alfalfa hay and triticale straw was digested, respectively. When the time of digestion was increased to 360 min, the sunflower hull showed 15.8% DM digestibility.
The characterization of four types of Indian honeys (Trifolium alexandrinum (berseem clover), Brassica sp. (mustard), Helianthus annuus (sunflower), Eucalyptus lanceolatus) was carried out on the basis of their quality parameters (moisture, pH, free acidity, reducing sugars, sucrose, fructose/glucose ratio, colour, ash content, proline content, invertase activity, diastase activity, hydroxymethylfurfural (HMF), and mineral content (sodium, potassium, iron, calcium, zinc, and copper). The source of honey had a significant (P<0.05) effect on moisture content, free acidity, pH, reducing sugar content, fructose/glucose ratio, hydroxymethylfurfural content, invertase and diastase activities, sucrose content, proline, ash content, and mineral content. Pattern recognition methods, such as principal component analysis and linear discriminate analysis, were performed to classify honey on the basis of physicochemical properties and mineral content. The variables calcium, pH, and potassium exhibited higher discrimination power.
An instrumentation and a tracer technique has been employed for the investigation of root bioactivity in plants with injected
75Se in a study carried out under field conditions. The investigation was based on a previously developed instrumentation and
on findings that 75Se is preferably transferred within the root system to the active tissues of the injected plants. The root bioactivity was
investigated in corn and sunflower as subjected to different fertilization and irrigation treatments. The pattern of root
bioactivity varied with crop, time and treatment applied. The technique showed to be reliable and easy-to-use and the detection
equipment scanned the radioactivity along the soil profile with good accuracy. The described method has proved to be a useful
tool to study under field conditions the root response to variations in moisture and nutrient status in the soil.
Authors:Brajendra Sharma, Umer Rashid, Farooq Anwar and Sevim Erhan
The increasing application of biobased lubricants could significantly reduce environmental pollution and contribute to the
replacement of petroleum base oils. Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates
for use as base fluids in formulation of environment friendly lubricants. Although many vegetable oils have excellent lubricity,
they often have poor oxidation and low temperature stability. Here in, we report the lubricant potential of Moringa oil, which
has 74% oleic acid content and thus possess improved oxidation stability over many other natural oils. For comparison, Jatropha
oil, cottonseed oil, canola oil and sunflower oil were also studied. Among these oils, Moringa oil exhibits the highest thermo-oxidative
stability measured using PDSC and TG. Canola oil demonstrated superior low temperature stability as measured using cryogenic
DSC, pour point and cloud point measurements. The friction and wear properties were measured using HFRR. Overall, it was concluded
that Moringa oil has potential in formulation of industrial fluids for high temperature applications.
Healthy eating, chiefly the quantity and quality of dietary fats and oils, takes a prominent part in promoting the optimal health status and in preventing the development of chronic disorders, mainly cardiovascular diseases. In Hungary the consumption of lard (the characteristic fat in the Hungarian diet) has fallen by 30% since 1980, and that of edible oil (above all sunflower oil) has been almost triplicated since 1970. The total fat consumption remained unchanged. From the eighties and nineties the mortality of cerebrovascular diseases, atherosclerosis and acute myocardial infarction significantly decreased, that of hypertension remained unchanged. Although cardiovascular diseases have a number of aetiological factors, the change of dietary fats and oils may play a role in the improvement of mortality data.
Authors:J. Chen, G. Grant, W. Boivin, M. Heinrich, A. Kerr and R. Tkachuk
A study has been carried out to determine the levels of radioisotopes in five Canadian grains from pre-(1985) and post-Chernobyl (1986) crop years. In addition, the radioisotope levels were determined in grains from the 1988 crop year consisting of wheats, oats, barley, corn and oil seeds which included flax, sunflower and canola. The grain and oil-seed samples were ashed to reduce their volume, and the gammaemitters137Cs and40K were determined using a high-purity germanium detector and a high-purity germanium well detector. The90Sr activity measurements required further ashing of the samples followed by chemical separations and -counting of the separated daughter90Y. The results for the 1985, 1986 and 1988 crop years are discussed and compared with results from grain crops obtained during years of atmospheric bomb tests in the 1950's.