Ultra-Wideband Temperature Dependent Dielectric Spectroscopy of Porcine Tissue and Blood in the Microwave Frequency Range.

The knowledge of frequency and temperature dependent dielectric properties of tissue is essential to develop ultra-wideband diagnostic technologies, such as a non-invasive temperature monitoring system during hyperthermia treatment. To this end, we characterized the dielectric properties of animal liver, muscle, fat and blood in the microwave frequency range from 0.5 GHz to 7 GHz and in the temperature range between 30 °C and 50 °C. The measured data were modeled to a two-pole Cole-Cole model and a second-order polynomial was introduced to fit the Cole-Cole parameters as a function of temperature. The parametric model provides access to the dielectric properties of tissue at any frequency and temperature in the specified range.

Addition of Sesamol Increases the Oxidative Stability of Beeswax Organogels and Beef Tallow Matrix Under UV Light Irradiation and Thermal Oxidation.

To enhance the oxidative stability of organogels made from canola oil, 40 ppm sesamol was added to beeswax-based organogels stored under ultraviolet (UV) light irradiation and 60 or 100 °C thermal oxidation conditions. To study the practical application of organogels as animal fat substitutes, beef tallow was mixed with organogels and their oxidative stability was determined under oxidative stress conditions. Without sesamol addition, the organogels and beef tallow with organogel oxidized rapidly under UV irradiation and thermal oxidation. The addition of 40-ppm sesamol decreased the consumption of headspace oxygen and the formation of primary and secondary oxidation products significantly (P < 0.05) compared with those in samples without the addition of sesamol, irrespective of oxidative stress. Sesamol improved the oxidative stability of organogels and beef tallow with organogel, which could be used in the meat industry. PRACTICAL APPLICATION: Organogels may replace trans-fat or highly saturated lipids in food products. The high degree of unsaturation and processing temperature mean that antioxidants are needed to extend the shelf life of organogels or organogel-containing products. The addition of sesamol significantly enhanced the oxidative stability of organogels and of beef tallow-containing organogels under UV irradiation and thermal oxidation conditions. Therefore, sesamol-supplemented organogels could replace saturated fats in beef tallow and prolong the shelf-life of meat products.

Sonocrystallization of Interesterified Soybean Oil: Effect of Saturation Level and Supercooling.

The aim of this study was to investigate the effects of supercooling and degree of saturation on lipid sonocrystallization under similar driving force of crystallization. Samples consisting of 100%, 50%, and 20% interesterified soybean oil (IESBO) diluted in high-oleic sunflower oil (HOSFO) were crystallized with and without high-intensity ultrasound (HIU). Two power levels were used by changing the amplitude of vibration of the tip (24 µm and 108 µm of tip amplitude). HIU operating at a frequency of 20 kHz was applied for 10 s. Sonication induced crystallization in the 100% IESBO sample and sonication power did not affect the results. A greater induction in crystallization was observed when higher power levels were used in the 50% IESBO sample, while no effect was observed in the crystallization kinetics of the 20% IESBO samples. Changes in the crystallization kinetics affected physical properties of the material, influencing elasticity. For example, sonication increased the elasticity of the 100% IESBO sample for both tip amplitudes from 435.9 ± 173.3 Pa to 72735.0 ± 9547.9 Pa for the nonsonicated and sonicated samples using 108 µm of amplitude, respectively. However, sonication only increased the elasticity in the 50% sample when used at the higher power level of 108 µm from 564.2 ± 175.2 Pa to 21774.0 ± 5694.9 Pa, and it did not affect the elasticity of the 20% IESBO samples. These results show that the level of saturation and the degree of supercooling affect sonication efficiency. PRACTICAL APPLICATIONS: High-intensity ultrasound (HIU) has been used as a novel method for changing the crystallization behavior of fats. HIU can be used to improve the physical properties of trans-free fats that are low in saturated fatty acids. Although recent studies have proven the effectiveness of this method to induce crystallization, the process must still be optimized to the industrial setting. All process parameters should be considered during the application of HIU, as they directly affect the final product. The aim of this paper was to investigate the effects of HIU and process conditions such as tip amplitude, degree of supercooling, and saturation level on the crystallization behavior of commercial interesterified soybean oil.

Enhanced creaming of milk fat globules in milk emulsions by the application of ultrasound and detection by means of optical methods.

The effects of application of ultrasonic waves to recombined milk emulsions (3.5% fat, 7% total solids) and raw milk on fat destabilization and creaming were examined. Coarse and fine recombined emulsions (D[4,3]=9.3 µm and 2.7 µm, respectively) and raw milk (D[4,3]=4.9 µm) were subjected to ultrasound for 5 min at 35°C and 400 kHz or 1.6 MHz (using a single transducer) or 400 kHz (where the emulsion was sandwiched between two transducers). Creaming, as calculated from Turbiscan measurements, was more evident in the coarse recombined emulsion and raw milk compared to that of the recombined fine emulsion. Micrographs confirmed that there was flocculation and coalescence in creamed layer of emulsion. Coalescence was confirmed by particle size measurement. These results imply that ultrasound has potential to pre-dispose fat particles in milk emulsions to creaming in standing wave systems and in systems with inhomogeneous sound distributions.

Use of ionizing radiation technology for treating municipal wastewater.

In big cities, the cost of treating wastewater is increasing with more stringent environmental requirements. Ionizing radiation technology for treating municipal wastewater may be an alternative to reduce treatment costs. In this paper, laboratory tests were carried out using different doses of radiation to treat wastewater samples collected from the AL-Rustamia wastewater treatment plant in Baghdad city. According to the results, irradiation by gamma radiation with a dose ranging from 100 to 500 krad was efficient in reducing some of the physical contaminants. The organic contaminants were degraded and reduced to about 12% of their original concentrations. Generally, irradiation technology could effectively modify the characteristics of the wastewater to such levels that are compatible with Iraqi disposal standards. The results of the study also showed that, an experimental pilot plant study is required to optimize the cost of wastewater treatment through the use of this technology.

Effects of gamma-irradiated fats on plasma lipid concentrations and hepatic cholesterol metabolism in rats.

Currently, there is a growing need for food irradiation that is effective in food preservation and quality improvement. Accordingly, this study was designed to observe the effects of gamma-irradiated dietary fat on plasma lipid concentrations and hepatic cholesterol metabolism in rats. Male rats were fed 5-kGy-gamma-irradiated beef tallow (gammaBT), corn oil (gammaCO), perilla oil (gammaPO), and nonirradiated fats (BT, CO, and PO) for 6 weeks. The gamma-irradiated fat feeding did not affect the plasma lipid concentrations. However, the hepatic cholesterol content was significantly higher in the rats fed gamma-CO as compared with the rats fed nonirradiated CO (40.0 vs. 28.2 mg/g liver). The hepatic HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase activities were not significantly different between the controls and the gamma-irradiated fat fed groups. However, the hepatic ACAT (acyl-CoA:cholesterol acyltransferase) activity was significantly lower in the gammaPO group as compared with its control group (138.2 vs. 404.5 pmol min(-1) mg(-1)). Among the nonirradiated groups, the ACAT activities of the CO and PO groups were higher than that of the BT group. The amounts of coprostanone, cholesterol, and total fecal neutral sterol were significantly higher in the gammaPO group as compared with the other groups. These results indicate that although slight changes in the lipid metabolism were observed as a result of 5-kGy-gamma-irradiated fat feeding, they were relative to the fat type and had no harmful consequences.

A 433 MHz Lucite cone waveguide applicator for superficial hyperthermia.

The effective field size (EFS, SAR > or = 50% of the maximum SAR at 1 cm depth) of a conventional 433 MHz water filled waveguide applicator (32 cm2, aperture area 100 cm2) has been increased by: (1) replacement of the two diverging brass side walls which are parallel to the direction of the electric field by Lucite walls; and (2) Placement of a heterogeneous permittivity in the centre of the aperture. SAR distributions were measured at several depths in layered fat-muscle phantoms. With Lucite side walls the SAR distribution becomes wider in the H-plane of the aperture, resulting in a circular SAR distribution. In this situation the EFS is 67 cm2. Additional insertion of a PVC cone with a top angle of 15 degrees at the centre of the aperture increases the EFS to 91 +/- 6 cm2 for a waterbolus of 18 x 18 x 1 cm3. The experiments also demonstrated that the resulting EFS is affected by the waterbolus size and shape. Calorimetric measurements showed that the efficiency of the improved applicator is comparable to the efficiency of the conventional water filled waveguide applicator, 50 and 56% respectively. The modifications reported provide a simple and inexpensive means to increase the EFS and can be easily implemented in water filled waveguide applicators.

[The application of microwave energy in preparation of herbal drugs. 2]. / Der Einsatz von Mikrowellenenergie zur Aufbereitung von Arzneidrogen. 2. Mitteilung.

On the basis of various plant organs the relation between the used microwave energy and the drying processes, temperatures of the surface and the interior of the drying materials as well as the remaining moisture in the drugs was investigated. Leaf, flower and herb drugs showed a similar drying behaviour. Plant material of high humidity, e.g. meaty fruits or roots, should be dried by means of pulsed microwave application to avoid too high temperatures. In almost all investigated drugs microwave drying resulted in a lower remaining moisture than air drying. The effect of microwave irradiation on carbohydrates, fats and proteins in plant materials was preliminarily investigated.

Stability of fat during irradiation and subsequent storage of irradiated buffalo meat.

Buffalo meat steaks were irradiated with gamma-rays in doses of 0,550 and 1100 krad and stored at 2 +/- 1 degree C. The changes in lipids extracted from the steaks were investigated. Peroxides and carbonyl compounds accumulated during irradiation and subsequent storage of the irradiated meat. Oxidation products were higher if irradiation was carried out with 1100 krad than with 550 krad. Soaking of the steaks in butylated hydroxy toluene (BHT) and sodium pyrophosphate before irradiation markedly reduced the amount of peroxides and carbonyl compounds formed during irradiation and storage. Treatment of meat muscle 800 V for 45 s reduced weeping but increased slightly the rate of autoxidation of lipids. The browning reaction was slow during cold storage of irradiated meat but increased upon storage of extracted lipids at room temperature.

The effect of ionizing radiation on the fatty acid composition of natural fats and on lipid peroxide formation.

The effects of irradiation doses of 200-1000 krad on the fatty acid compositions of saturated and unsaturated natural food fats have been studied. Lard, coconut oil, corn oil, methyl linoleate and herring oil have been analysed before and after irradiation for lipid peroxide content and fatty acid composition. The effects of storage under varied conditions after irradiation have also been investigated. Irradiation doses of 200-1000 krad had little effect on the fatty acid compositions of saturated fats (lard and coconut oil) or of fats with a high antioxidant content (corn oil) but caused destruction of 98 per cent of the highly unsaturated acids (18: 4,20 :5,22 : 6) and 46 per cent of the diene acids (18:2) in herring oil. The destruction of the polyunsaturated fatty acids increased with increasing storage temperature and storage time. The destruction of polyunsaturated fatty acids is accompanied by an increase in lipid peroxide formation. It is considered that changes in fatty acid composition in natural foods after irradiation are important in consideration of the use of irradiation for food preservation.

The nutritional value of irradiated casein-fat mixtures-effect of anaerobic conditions, storage time, added vitamin E and degree of unsaturation of lipids.

The effect of oxygen elimination during irradiation (5 Mrad) and subsequent storage, storage time (12 weeks), degree of lipid-unsaturation and added antioxidant (vitamin E) in protein-lipid mixtures (casein : fat - 11.1 : 4) on the nutritive value of protein was studied during 8-day nitrogen balance trials in 12 groups of 6 weanling rats each. When casein-cocofat-cornoil mixtures were irradiated and stored under aerobic conditions a reduction of NPU appeared upon prolonged storage time, which was prevented by excluding oxygen during irradiation and storage. When the lipid component consisted entirely of cocofat no loss in NPU occurred under aerobic processing and storage conditions throughout the 12 week storage period. Replacement of cocofat through sunfloweroil resulted in a drastic reduction of NPU and in growth inhibition, which was not prevented by the addition of vitamin E (0.05 g/100 g lipid). Irradiation of casein-lipid mixtures resulted in a significant increase of carbonyl compounds. A further increase was effectively prevented by elimination of oxygen during irradiation and storage. A drastic increase of carbonyl compounds as well as a significant reduction of available lysine occurred in casein-sunfloweroil mixtures. Added vitamin E afforded only limited protection against these changes.

[Organoleptic changes in beef and pork fats following gamma-ray irradiation]. / Organoleptichni promeni v govezhdite i svinskite tlustini sled obluchvane s gama-luchi

Studied were bovine and swine fats that had been treated with gamma-rays at the rates of 0.10 to 2.00 Mrad, in the presence of oxygen and in an atmosphere containing no oxygen as well as under storage conditions at 2 to 4degreesC, and -- 18 and up to --20degreesC, for 45 and 90 days, respectively. When doses of 0.25 Mrad were used no changes in the organoleptic properties were observed. Fats that were treated at the rate of more than 0.25 Mrad in the presence of oxygen assumed 'side' smell and taste. If irradiation was carried out in the absence of oxygen no such deviations from the normal taste and odor were noted--at rates of up to 0.70 Mrad for the swine fats, and at rates of more than 0.50 Mrad for the bovine fats. Destruction of the yellow pigment in the bovine fats was observed at treatment with doses higher than 0.70 Mrad. The changes in the organoleptic properties corresponded to the changes taking place with the peroxides, the water soluble fatty acids, and the epihydrinaldehyde. Changes in the organoleptic properties (odor and taste) in the bovine fats took place at lower doses of iradiation than in the swine fats.

[Influence of gamma-rays on the general acidity and the water-soluble fatty acids of swine and cattle fats]. / Vliianie na gamma-l'chite v'rkhu obsnchata kiselinnost i v'v voda mastni kiselini v svinskite i govezhdite tl'stini

Studied were the changes in the total acidity and the amount of the water-soluble fatty acids in bovine and swine fats following the irradiation with gamma-rays. The treatment was effected by means of a 60Co source at 12--15 degrees C. The samples were kept at temperatures ranging from 2 to 4 degrees C, and from --18 to --20 degrees C in the course of 45 and 90 days, resp., being irradiated in the presence and absence of oxygen at rates of from 0.1 up to 2.0 Mrad. Results showed that gamma-treated at the rate of up to 2.00 Mrad produces no effect on the changes observed with the total acidity and the changes taking place during storage. The changes of the water-soluble fatty acids in the presence of oxygen, the type of fat, the temperature value, and the period of storage. The higher the irradiation rates used the greater the changes and shorter the time they need to take place. The presence of oxygen also proved of substantial importance for the changes in the amount of the watersoluble fatty acids. Bovine fats proved more sensitive to the changes referred to than swine fats.