Investigation of the long-term toxic effect of nanoparticles of different physical-chemical characteristics

D.G. Churilov¹, S.D. Polischuk²*, G.I. Churilov³, V.V. Churilova² and D.N. Byshova⁴

¹Ryazan State Agrotechnological University, Road Transport Faculty, Department of Metal Technology and Machine Repair, Kostychev street 1, 390044 Ryazan, Russia
²Ryazan State Agrotechnological University, Technological Faculty, Department of Breeding and Seed Production, Agricultural Chemistry, Forestry and Ecology, Kostychev street 1, 390044, Ryazan, Russia
³Ryazan State Medical University, Faculty of Medicine, Department of General Chemistry, Vysokovoltnaya street 9, 390026 Ryazan, Russia
⁴Ryazan State Agrotechnological University, Faculty of Vet Medicine and Biotechnology, Kostychev street 1, 390044 Ryazan, Russia
*Correspondence: svpolishuk@mail.ru

Abstract:

The purpose of this work is to study the effect of metal and oxide nanoparticles on some ecological and functional groups in the soil-plant-animal system to form the stability limits of organisms. Nanoparticles of cobalt, iron, zinc, copper, copper oxide, zinc oxide and titanium dioxide sized 20–80 nm were studied. The concentration range was 0.01–1,000 g of nanoparticles per ton of seeds or soil. Objects suitable for biotesting and environmental monitoring were selected: earthworms (Lumbricina), rats (white outbred) and Wistar rats. It was previously found that nanoparticles of the studied metals up to a concentration of 100 g t^-1 of seeds, unlike oxides, practically do not affect bacterial populations. The use of indicators of biochemical and cytomorphologic reactions of invertebrates seems promising because worms are able to bind pollutants and reduce their penetration into plants. They are also an indicator of soil biotesting for metal contamination. Reactivity and toxic effects of nanoparticles (NPs) in natural conditions depend both on the type of soil and on the size and concentration of nanoparticles. With sizes (NPs) of up to 20 nm (depending on the type of soil and physicochemical characteristics), NPs are much more reactive and reduce the survival of microorganisms. Small nanoparticles (less than 20 nm) are characterized by a large interface. Such nano-objects exhibit high physical-chemical activity and are safe only at very low concentrations. The specifics of the environmental impact of oxide NPs compared to metal NPs was revealed. It was associated with accumulation of oxides in living systems and the peculiarities of changes in the morph physiological, histological and reproductive parameters of organisms and morphological and biochemical parameters of animals. Oxide nanoparticles accumulate in a living organism, exhibit toxic properties, lower the activity of enzymes and hormones and are transferred along trophic chains, which is not typical for metal nanoparticles.

Key words:

biochemistry, cytotoxicity, histology, invertebrates, laboratory animals, microorganisms, morphology, plants, toxicity

Effect of high pressure processing on raw pork microstructure and water holding capacity

S. Sazonova, I. Gramatina*, D. Klava and R. Galoburda

Latvia University of Life Sciences and Technologies, Faculty of Food Technology, Department of Food Technology, 22 Rigas street, LV-3001 Jelgava, Latvia
*Correspondence: ilze.gramatina@llu.lv

Abstract:

High pressure processing (HPP) is widely used as an alternative to thermal food preservation technologies, including processed meats treatment. This technology affects food texture and water-holding capacity, which may have beneficial effect on product yield. After thermal treatment, meat partially releases water together with water-soluble proteins, which is concerned as a loss. It is very important not only because of changes in taste properties, but also economic aspects such as reduced final product weight. The aim of the study was to evaluate changes in the meat microstructure and water-holding capacity upon high pressure treatment. Pork samples were treated at various pressures and holding times, namely, 300 and 600 MPa with a 1 and 15 minutes holding time at each pressure. Untreated sample was regarded as a control. Microstructure of pork meat was evaluated after the paraffination of the samples. Fibre cross section area and space between fibres were measured and reported. Water-holding capacity was measured by centrifugation of meat samples over filter and calculating released amount of juice. Results indicated that fibre size did not change significantly after treatment at 300–600 MPa pressure comparing to the control sample – untreated meat. However, high pressure can affect hydrophobic properties of myofibrillar protein. The experimental results showed that water-holding capacity increases with the high pressure treatment. It is an important issue in meat processing industry, because HPP treatment allows reducing the water loss in fresh pork.

Key words: