The simplest way to eliminate microorganisms in the must/wine is through sulfuration, as it allows the introduction of pure yeast varieties into the must, which guarantees a high-quality wine. However, sulfur is an allergen, and an increasing number of people are developing allergies to it. Therefore, alternative methods for microbiological stabilization of must and wine are being sought. Consequently, the aim of the experiment was to evaluate the effectiveness of ionizing radiation in eliminating microorganisms in must. The sensitivity of wine yeasts, Saccharomyces cerevisiae, S. cerevisiae var. bayanus, Brettanomyces bruxellensis, and wild yeasts to ionizing radiation was com-pared. The effects of these yeasts on wine chemistry and quality were also determined. Ionizing radiation eliminates yeast in wine. A dose of 2.5 kGy reduced the amount of yeast by more than 90% without reducing the quality of the wine. However, higher doses of radiation worsened the organoleptic properties of the wine. The breed of yeast used has a very strong influence on the quality of the wine. It is justifiable to use commercial yeast breeds to obtain standard-quality wine. The use of special strains, e.g., B. bruxellensis, is also justified when aiming to obtain a unique product during vinification. This wine was reminiscent of wine produced with wild yeast.. The wine fermented with wild yeast had a very poor chemical composition, which negatively affected its taste and aroma. The high content of 2-methylbutanol and 3-methylbutanol caused the wine to have a nail polish remover smell.
Electrons with energies of 300 keV or lower have the potential to decontaminate the surfaces of various types of food products with minimal loss of quality. The aim of the present work was to determine the thickness of the layer inhabited by microorganisms. The food samples tested were black and white pepper irradiated with 200 keV, 230 keV, 300 keV and 9 MeV beams of electron energy. To determine the depth from the surface which can be inhabited by microorganisms two approaches were tested. The methods used were based on the application of different microbiological recovery techniques and the microbial effectiveness of the irradiation process depending on the energy of the electron beam. It was observed that the layer which microorganisms may contaminate differed for the tested samples it was estimated as being below 100 μm thick for white pepper and about 200 μm for black pepper. The penetration ability was significant in experiments performed, and as a result the electron beam at the lowest levels tested (200 and 230 keV) was found to be insufficient to effectively decontaminate the black pepper samples. The beam of energy 300 keV was found to have a similar microbial inactivation effect as the high energy electron beam (9 MeV).
Potassium metabisulphite is usually used for microbial stabilization in the process of vinification and wine preservation, but it is considered to be allergenic. The objective of the present study was to assess the efficiency of ozonation and ionizing radiation as alternatives to wine sulphurization. The efficiency of yeast removal and the retention of the chemical quality of wine were evaluated. Wine was subjected to 60 min of ozonation, and radiation doses were set at 1-10 kGy. Moreover, a combination of ozonation and ionizing radiation treatment was used. The ozonation of wine did not produce the expected results. That is, it did not limit the number of yeast cells. From the sixth minute, a significant deterioration in the taste and the color of the wine was found. Ionizing radiation at a dose of 1 kGy reduced the yeast count by 95.5%, and a reduction of 99.9% was seen after the application of 2.5 kGy. Moreover, these doses did not have a significant effect on the organoleptic properties or the chemical composition of wine. The total amount of polyphenols reduced from the maximum of 1127.15 to 1023.73 mg at the dose of 5 kGy. Radiation is widely used to preserve food products. Its use for finished wine preservation may be an alternative to sulphurization.
Electrons with energies of 300 keV or lower have the potential to decontaminate the surfaces of various types of food products with minimal loss of quality. The aim of presented work was to determine the effectiveness of the process when applied to naturally contaminated food samples. Black pepper, white pepper and allspice samples were irradiated using electron beam at energy of 300 keV (low energy e-beam) and 10 MeV (high energy e-beam) to confirm the inactivation of bacteria. Total aerobic bacteria were counted before and after the irradiation and bacterial species were determined by a microbial identification system based on MALDI-TOF mass spectrometry. The range of applied low energy electron beam in food products estimated based on the depth-dose profile of electron beam and density of samples was about 300 mu m thick. The log reduction in the total number of aerobic bacteria for spices samples irradiated with the high energy e-beam was comparable with that of the low energy e-beam, if estimated doses delivered on the surface were equivalent. (The log reduction by irradiation with 300 keV e-beam for 5 min corresponded to that by ca. 6 kGy irradiation with 10 MeV e-beam in conditions employed in this study). In non-irradiated spices, the dominant species was Bacillus subtilis. In irradiation of black pepper, the dominated species that survived after the irradiation were Cronobacter sakazaki and Bacillus megaterium, regardless of the energy of the electron beam. The effectiveness of microbial decontamination by both the low and the high energy e-beams was comparable for spices, where microorganisms exist in the surface layer. This study suggests the low energy e-beam as an alternative technology for the currently used highly penetrating ionising irradiation to eliminate microbial contamination of spices.
Unsuitable storage conditions or accidents such as floods can present a serious threat for large quantities of book making them prone to attack by harmful microorganisms. The microbiological degradation of archives and book collections can be efficiently inhibited with irradiation processing. Application of EB irradiation to book and archive collections can also be a very effective alternative to the commonly used ethylene oxide treatment, which is toxic to the human and natural environment. In this study was evaluated the influence of EB irradiation used for microbiological decontamination process on paper-based objects. Three different kinds of paper (Whatman CHR 1, office paper and newsprint paper) were treated with 0.4, 1, 2, 5, 10 and 25 kGy electron beam irradiation. Optical and mechanical properties of different sorts of paper treated with e-beam, before and after the radiation process were studied. These results, which correlated with absorbed radiation doses effective for the elimination of Aspergillus niger (A. niger) allowed to determine that EB irradiation with absorbed radiation dose of 5 kGy ensures safe decontamination of different sorts of paper-based objects.
The effectiveness of the radiation decontamination process was tested for electron beam of energy 200 keV and 300 keV. The energy of electrons was controlled by the measurements of its penetration ability in stack of B3 dosimetric film. In the presented work, the reduction of total aerobic bacteria count was observed, depending on time of irradiation for samples of dried black pepper, onion flakes and bay leaves. The results were compared with the effect observed for the process where high energy electron beam was used.
Effectiveness of electron beam irradiation was evaluated against Phytophthora nicotianae var. nicotianae, the causal agent of stem base and root rot of tomato. In laboratory trials, irradiation of 7-day-old Phytophthora cultures growing on potato-dextrose-agar (PDA) medium with 1 kGy resulted in the disintegration of the pathogen’s hyphae. Increasing the irradiation dose to 3 kGy caused decay of the hyphae. Irradiation of infested stonewool with 5 kGy caused decrease of the pathogen population about 5 times. Application of 20 kGy completely eliminated the pathogen from stonewool. Irradiation of substratum resulted in significant increase of tomato seedlings healthiness, especially when the dose 20 kGy was applied.
Ionizing radiation was applied as a substrate pretreatment method in the process of bioethanol production. The aim of the presented work was to determine the changes in the morphology of willow plant fibers caused by the interaction of a high energy electron beam with lignocellulosic biomass. The microstructure was examined with a scanning electron microscope and X-ray computer microtomography. Additionally, sorption analysis was carried out in order to determine specific surface area and porosity. The analysis carried out after the treatment of lignocellulose with an electron beam indicated destruction of cell walls, observed as a decrease in the smoothness and an increase in the roughness of the surface of the fibers. The changes in surface texture and fiber integrity affected the specific surface area and porosity of the tested samples. The specific surface area, the total volume of pores and the average pore diameter were calculated based on the isotherms of nitrogen sorption. The increase in the specific surface area was observed to occur simultaneously with the increase in the average diameter of pores.
Mathematical model is the basis for computer decision support system (DSS) connected with food security strategy, in which food irradiation is one of the methods used for elimination of substance with pathogens. Such system can support an organisation of many different activities in the area of food safety. It can be designed for a specific region, country, etc., and is addressed to State Sanitary Inspection offices. The paper demonstrates the capabilities of the system in modeling activities of sanitary inspection teams aimed at pathogen elimination with the use of electron beam irradiation in procedures of utilisation of animal originated food, related packaging, or other microbiologically contaminated materials. It describes new application of both computer supported decision systems and radiation processing. The elaborated mathematical models show human activities in the process of microbiological contamination elimination.
This paper presents the results of the studies on changes of selected quality parameters of hydrobiodegradable aliphatic-aromatic copolyester (AAC). Radiation treatment was performed at the Institute of Nuclear Chemistry and Technology in Warsaw, using cobalt gamma-ray sources "Issledovatel" (dose rate 0.389 Gy/h) and "GC 5000" (8.5 Gy/h). The material was subjected to the impact of radiation doses of 5, 10, 20 and 40 kGy. Selected parameters of the packaging material, important from the standpoint of a potential application, have been studied: gaseous products of radiolysis, strength parameters in accordance with PN EN ISO 527-3, global migration PN-EN-1186-1:2002, FT-IR analysis using PCA method, contact angle measurement using the drop shape method. The results have demonstrated that there is no significant influence of ionizing radiation on AAC film parameters. Correlation between doses applied and values of measurements has not been found.
Effectiveness of electron beam irradiation was evaluated against Rhizoctonia solani, which is one of the most dangerous soil-borne pathogen, causing stem base and root rot of many horticultural plants. Treatment of in vitro cultures with 0.5 kGy significantly inhibited the pathogen's growth and the spread of necrosis on chrysanthemum leaf blades inoculated with the irradiated cultures. Application of e-beam irradiation for peat disinfection resulted in a two-fold decrease rot development in chrysanthemum stem at a dose of 5 kGy and complete inhibition at 10 kGy. For the elimination of R. solani from composted pine bark and its mixture with peat, irradiation of both substrates with 15 kGy was necessary.
Very extensive production procedure, especially in plants growing under covering, require methods, which would allow quick elimination or substantial reduction of populations of specific pathogens without affecting the growth and development of the cultivated plants. Among soil-borne pathogens, the Phytophthora species are especially dangerous for horticultural plants. In this study, irradiation with electron beam was applied to control Phytophthora cinnamomi. The influence of irradiation dose on the reduction of in vitro growth and the population density of the pathogen in treated peat and its mixture with composted pine bark (1:1), as well as the health of Chamaecyparis lawsoniana and Lavandula angustifolia plants were evaluated. Application of irradiation at a dose of 1.5kGy completely inhibited the in vitro development of P. cinnamomi. This irradiation effect was connected with the disintegration of the hyphae and spores of the species. Irradiation of peat and its mixture with composted pine bark with 10kGy resulted in the inhibition of stem base rot development in Ch. lawsoniana. Symptoms of the disease were not observed when the substrates were treated with 15kGy. In the case of L. angustifolia, stem root rot was not observed on cuttings transplanted to infected peat irradiated at a dose of 10kGy. Irradiation of the horticultural substrates did not affect plant growth.
Electron beam (EB) irradiation was tested against Botrytis cinerea,Pythium ultimum and Phytophthora citricola the most dangerous pathogens causing stem and root rot of seedlings, cuttings and older plants. In the laboratory trials cultures of 3 species were irradiated with doses 0 (control), 1.5, 3.0, 4.5 and 6.0 kGy whereas peat was treated with 10, 15 and 25 kGy. P. citricola was the most sensitive species for irradiation. In greenhouse trials 15 kGy irradiation of peat protected chrysanthemum cuttings against B. cinerea and P. ultimum as well as rhododendron young plants against P. citricola. Irradiation of peat did not influence the growth and development of the tested plants.
Electron beam irradiation was tested against Fusarium oxysporum f. sp. dianthi (Fod) a pathogen causing Fusarium wilt of carnation. Efficiency of the different radiation doses on in vitro survival and development of Fod culture on potato-dextrose agar (PDA) medium was tested. A dose of 6 kGy completely inhibited the pathogen growth. Application of radiation for microbiological decontamination of four substrates used for carnation production demonstrated that, depending on the type of substrate, doses of 10 or 25 kGy were effective in Fod elimination. All carnation plants cultivated on radiation decontaminated substrates were healthy.
Dose reader CD-07 has been introduced for measurements of a dose distribution during dose mapping exer- cises and for calculations of electron beam energy. This instrument consists of an SP-880 spectrophotometer equipped with a driving motor to move a dosimetric foil across light beam in the front of narrow light aperture. To control the movement of the foil and to present and store the measuring results a specialized software has been developed. In this paper the use of dose reader CD-07 in Performance Qualification of irradiated herbs was described.
Nanotechnology is one of the fastest developing new areas in science and technology. Ionizing radiation is widely applied for nanostructure synthesis and nanomaterials modification. The ability to fabricate structures with nanometric precision is of fundamental importance to any exploitation of nanotechnology. Nanofabrication involves various lithographies to write extremely small structures. An interesting field of radiation nanotechnological application concerns the development of nano-ordered hydrogels for biosensors. New trends and more precise treatment technology were applied: surface curing and modification, polymer functionalization are good examples of such developments. Patents on application of ionizing radiation in nanotechnology focused on many different approaches to this topic, not only nanoparticles synthesis but also nanostructure modification or functionalization.
In recent years there is a trend in industry to limit the usage of chemical compounds. Natural polymers are new promising materials that possess important properties like biodegrability or lack of toxicity. Radiation processing of natural occurring polymers is an area of current research for development of new applications. The aim of this study was to determine the impact of ionizing radiation modification on bioactivity of a natural polysaccharide. Chitosan with different molecular weights was investigated as a biostimulator - a biologically active substance that stimulates some growth processes in plants. Chitosan in solid state was irradiated with electron beam from an electron beam accelerator Elektronika 10-10 with a dose range from 50 to 300 kGy. The effects of irradiation on the molecular weight of chitosan were investigated by viscosity and GPC measurements. Non-irradiated and irradiated chitosan at concentrations 0.001, 0.01, 0.1 and 1 g/dm(3) were used for greenhouse tests of its activity for growth promotion of Salix viminalis L. var. gigantea plant. Uniform rooted cuttings (20 per combination) were selected for the test and cultivated in aerated hydroponics culture containing Hoagland's nutrient solutions plus respective amounts of chitosan. After six weeks of plant exposure to chitosan, data of selected parameters of plant growth were collected. In most cases, except the highest concentration, both forms of chitosan had stimulatory effect on leaf area, length of roots and of newly developed shoots. Also fresh and dry weights of these organs were greater in chitosan treated plants. The highest concentration of chitosan was stimulatory only for a number of roots and newly developed shoots while for other parameters was inhibitory. In comparable concentrations the stimulatory effect was greater for chitosan irradiated in comparison with the non-irradiated one.