Use Of Gamma Radiation Research Articles

Ellagitannin-rich bioactive extracts of Tuberaria lignosa: insights into the radiation-induced effects in the recovery of high added-value compounds.

Ellagitannins are polyphenols responsible for a number of bioactivities and health-promoting effects. These industrially important molecules can be affected by post-harvest treatments and recovery processes, but little is known about the irradiation-induced effects on their integrity, bioactivity and extractability. Herein, the impact of gamma radiation on the production of ellagitannin-rich extracts was investigated using Tuberaria lignosa as a case study. These effects were compared with those induced in flavonoids and organic acids. The extracts were particularly rich in hydrophilic antioxidants (measured by in vitro assays). The recovery of different phytochemicals was favoured by longer extraction times. Ellagitannins (mainly punicalagin derivatives) were extracted better from samples irradiated at 5 kGy and were not significantly affected by the 10 kGy dose. However, the total contents of flavonoids and organic acids were decreased by the consequent increase in irradiation dose. Therefore, this study supports the use of gamma radiation for processing T. lignosa, aiming to obtain ellagitannin-rich bioactive extracts.

Radiation Grafting for the Functionalization and Development of Smart Polymeric Materials.

Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone as a result of the high-energy radiation exposition over the polymeric material. Thus, a microenvironment suitable for the reaction among monomer and/or polymer and the active sites is formed and then leading to propagation to form side-chain grafts. The modification of polymers using high-energy irradiation can be performed by the following methods: direct or simultaneous, pre-irradiation oxidative, and pre-irradiation. The most frequently used ones correspond to the pre-irradiation oxidative method as well as the direct one. Radiation-grafting has many advantages over other conventional methods because it does not require the use of catalyst nor additives to initiate the reaction and usually no changes on the mechanical properties with respect to the pristine polymeric matrix are observed. This chapter is focused on the synthesis of smart polymers and coatings obtained by the use of gamma radiation. In addition, the diverse applications of these materials in the biomedical area are also reported, with focus in drug delivery, sutures, and biosensors.

Use of gamma radiation on control of Clostridium botulinum in mortadella formulated with different nitrite levels

Abstract This study investigated the effects of applying different doses of gamma radiation (0, 10 and 20 kGy) on Clostridium botulinum spores (107 spores/g) inoculated into mortadellas with different nitrite contents (0, 150 and 300 ppm). We also evaluated the order of application of heat (cooking) and irradiation processing. The products were evaluated for survival of C. botulinum, pH, water activity (Aw), redox potential (Eh) and residual nitrite content. In the non-irradiated raw batters, almost all spores could be recovered when no nitrite was added and only half was recovered with the addition of 150 ppm of nitrite. The use of 150 ppm of nitrite was able to inhibit the germination or growth of C. botulinum in non-irradiated cooked mortadellas after 48 h of processing. However, after 30 days of chilling storage (4 °C), it was possible to recover 105 UFC/g of this microorganism. The gamma irradiation (>10 kGy) had a positive effect on the inactivation of C. botulinum in mortadellas, independent of the sodium nitrite level used and the cooking/irradiation processing order.

Low doses of gamma radiation in the management of postharvest Lasiodiplodia theobromae in mangos.

The postharvest life of mango is limited by the development of pathogens, especially fungi that cause rot, among which stands out the Lasiodiplodia theobromae. Several control methods have been employed to minimize the damages caused by this fungus, chemical control can leave residues to man and nature; physical control by the use of gamma radiation in combination with modified atmosphere and cold storage. The use of gamma radiation helps to reduce the severity of the pathogen assist in the ripening process of fruits, even at low doses (0.25, 0.35 and 0.45 kGy) chemical properties such as pH, soluble solids, acid ascorbic, titratable acidity and also the quality parameters of the pulp showed no damage that are ideal for trade and consumption of mangoes. This treatment can be extended for use in the management of diseases such as natural infections for penducular rot complex that has as one of L. theobroma pathogens involved.

Aplicação de filmes biodegradáveis produzidos a partir de concentrado proteico de soro de leite irradiado

RESUMO Filmes biodegradáveis à base de proteínas de soro de leite apresentam grande potencial para aplicação como embalagens, devido às suas excelentes propriedades mecânicas e ópticas. Contudo, alguns processos, como a aplicação de radiação gama, podem afetar as propriedades físicas, mecânicas e cor dos filmes produzidos a partir dessas proteínas. Objetivou-se, com este estudo, produzir filmes biodegradáveis a partir de concentrado proteico de soro de leite irradiado (50 kGy) e avaliar a sua eficiência como embalagem para maçã. A aplicação de filmes elaborados com proteínas de soro de leite irradiadas não se apresentou como uma boa barreira à perda de umidade, quando submetidos à temperatura de 25 ºC e umidade relativa de 55 %, porém, é uma ótima alternativa para a preservação da cor, retardando o escurecimento da maçã após o corte.

Effects of Gamma Radiation (Co 60) in Cachaça containing grapes (Crimson)

<p>The current study deals with <em>cachaça</em> irradiation in the presences of grapes, with the use of gamma radiation (Co 60) to evaluate its effects on the physical and chemical characteristics of this beverage. The research had as objective to assess the effects of irradiation in <em>cachaças</em>, in the extraction of compounds present in the pickled grapes in the <em>cachaça</em>. Samples were prepared with grapes type Crimson, in polypropylene bottles, with and without grapes. Both types of samples were irradiated with doses of 0 (control) and 300Gy. Later were performed physical and chemical analyzes (pH, titratable acidity, soluble solids) during a 5-day span after irradiation treatment. Significative statistical difference was noticed in titratable acidity of the samples that contained grapes, larger values when compared with pure samples. However, there was no statistical difference when comparing the pure beverage with control or the beverage containing grapes and control. For pH the values for the samples with grapes is statistically lower than the others. The results for soluble solids (ºBrix) displayed an increase on both types of samples comparing with their respective controls. In conclusion, the 300Gy dose was effective for increasing soluble solids quantity both in pure <em>cachaças</em> as in presences of grapes. Relating to pH and acidity, this dose shows interference when grapes are presents.</p><p> </p><p>DOI: 10.14685/rebrapa.v6i1.199</p>

English

This work aimed to study the effect of gamma radiation on the production of enzymes by filamentous fungi present in the seawater used for thermoelectric Termope S / A, in the vicinity of Port of Suape, Pernambuco. The isolated microorganisms were screened for their ability to produce enzymes. Subsequently, the fungi were irradiated at 3 doses (500, 1000 and 1500 Gy), using 4 inoculation techniques: lyophilisation, scraping of the spores, glass beads and agarose block. A fermentation assay for enzyme production was made in simple batch using a bioreactor New Brunswick, model Bioflo 110. The best enzyme produced was lignin peroxidase (676 U/L) by Aspergillus awamori in 500 Gy dose. Manganese peroxidase enzyme (1720 U / L), produced by three species of fungi (Penicillium sp.), was the highest in 500 Gy dose. Aspergillus terreus produced laccase enzyme (980 U/L) better in 500 Gy dose. In the assay of the fermentation bioreactor, the best results were found in BH-amid corn steep liquor, where 650 U/L of laccase was produced at the baseline and also in the medium containing corn steep liquor, where 620 U/L laccase was produced during 72 h. This is better than Sabouraud. The use of gamma radiation increased the production of enzymes by filamentous fungi compared to tests without radiation. Statistical analysis shows there are no significant differences between the inoculation techniques, and the best dose of radiation tested was 500 Gy. In trial bioreactor containing Bushnell Haas + corn steep, Penicillium sp. produced larger amounts of phenoloxidases enzymes compared to Sabouraud medium. Irradiation in a dose of 500 Gy stimulates A. awamori, A. terreus and Penicillium sp. to produce phenoloxidases enzymes. Key words: Aspergillus, penicillium, corn steep, radiation.

Smart Polymers and Coatings Obtained by Ionizing Radiation: Synthesis and Biomedical Applications

Gamma radiation has been shown particularly useful for the functionalization of surfaces with stimuli-responsive polymers. This method involves the formation of active sites (free radicals) onto the polymeric backbone as a result of the exposition to high-energy radiation, in which a proper microenvironment for the reaction among monomer and/or polymer and the active sites takes place, thus leading to propagation which forms side chain grafts. The modification of polymers using high-energy irradiation may be performed by the following methods: direct or simultaneous, pre-irradiation oxidative and pre-irradiation. The most frequent ones correspond to the pre-irradiation oxidative method and the direct one. Radiation-grafting has many advantages over conventional methods considering that it does not require catalyst nor additives to initiate the reaction, and in general, no changes on the mechanical properties with respect to the pristine polymeric matrix are observed. This chapter focused on the synthesis of smart polymers and coatings obtained by the use of gamma radiation. In addition, diverse applications of these materials in the biomedical field are also reported.

On the Use of Gamma Radiation to Change the Characteristics of Porous Poly(caprolactone) Tissue Scaffolds

Optimizing the structural of porous tissue scaffolds to maximize their performance in tissue engineering applications is difficult and time-consuming. The interdependence of different processing parameters means that it is difficult to optimize the properties of the scaffolds during manufacture. The authors report a simple method of changing the permeability of polycaprolactone scaffolds through controlled exposure to gamma radiation. 30 kGy of gamma radiation increases the permeability of water and bovine serum albumin through the scaffolds by approximately 80%. The authors also demonstrate that performance measures can detect subtle changes in complex structures that are difficult to detect using SEM.

Gamma radiation: An efficient technology to conserve the quality of fresh raspberries

Raspberries have short postharvest life and decay rapidly. A technology that is increasingly being used to inhibit the growth of these microorganisms and simultaneously delay fruit senescence is gamma ray irradiation. The aim of this study was to evaluate the effectiveness of this technology in cold-stored fresh raspberries postharvest and to find the best irradiation dose. Raspberries were purchased from a commercial orchard. The doses applied were of 0.5, 1.0 or 2.0kGy, and the fruit was stored at 0°C and 90% RH after the irradiation. Non-irradiated fruit was used as the control. The results indicated that the application of gamma rays did not alter the respiratory rate, ethylene production, flesh firmness, anthocyanins content or color index of the raspberries. The use of gamma radiation in doses of 1.0 and 2.0kGy, associated with cold storage, extended the postharvest life of fresh raspberries by 8 days. The 1.0kGy dose is considered the most useful one that reduces the decay incidence and weight loss and presents the lowest reduction in ascorbic acid. However, to recommend its use, it is necessary further studies about the effect of this dose in the bioactive and nutritional compounds of the raspberries.

Role of activated carbon on micropollutans degradation by ionizing radiation

The objective of this study was to analyze the influence of the presence of activated carbon on the degradation of the triiodinated contrast medium diatrizoate (DTZ) by the simultaneous use of gamma radiation and activated carbon. Four commercial activated carbons (Ceca, Witco, Sorbo, and Merck) with different textural and chemical characteristics were used for this purpose. The percentage DTZ removal obtained was considerably higher with the gamma radiation/activated carbon (GM/AC) system than with radiolysis in the absence of activated carbon, and it depended on the specific activated carbon employed. First, we optimized the amount of activated carbon required to maximize the amount of DTZ removed by the GM/AC system (0.06g). The degradation constants were higher with the GM/AC system than with radiolysis alone, evidencing a synergic effect that favors pollutant removal. This synergic effect is independent of the textural but not the chemical characteristics of the activated carbon, observing a higher synergic activity for carbons with a higher surface content of oxygen, specifically quinone groups. We also highlight that the synergic effect of the activated carbon requires adsorbent–adsorbate electrostatic interaction and is absent when this interaction is hindered.

ENVELHECIMENTO PRECOCE DE CACHAÇA COM IRRADIAÇÃO GAMA (Co60) ATRAVÉS DA EXTRAÇÃO DE COMPOSTOS DA UVA

The sugar cane spirit is a drink distilled and for this reason your bouquet and flavor need enhanced. Usually the sugar cane spirit goes through a process of maturation in wooden barrels. However it is possible to obtain similar results with the use of gamma radiation emitted by the radioisotope Co60. This research aimed to evaluate the effects of irradiation in the sugar cane spirit including the possibility of premature aging having as reference the color change through the extraction of existing compounds in the grape. Sugar cane spirit samples were prepared with grapes like Crimson in polypropylene bottles. The samples were irradiated at doses of 0 (control); 300Gy; 2kGy; 6kGy and then colorimetric analysis was performed in periods of 5; 10; 20 and 50 days after irradiation treatment. There was no statistically significant difference in measurements of L, a, b or the Chroma and Hue-Angle from 5; 10 and 20 days. In the 50 th day just to measure a significant difference in the dose of 300Gy which was higher than 2 and 6kGy and not different from control sample. Therefore this study showed that the irradiation at doses of 300Gy; 2kGy and 6kGy are not efficient for the purpose of extracting the compounds of the grape for a change in color that is the indicative of possible premature aging.

The Effect of Gamma Sterilization on the Insecticidal Toxicity of Engineered and Conventional <I>Bacillus thuringiensis</I> Strains

This study evaluates the effect of gamma radiation on the spore activity, toxicity, and crystal structures of two engineered Bacillus thuringiensis (Bt) strains, TnX and TnY, and the reference Bt strain HD-1. We attempted to identify dosages of cobalt-60 gamma radiation that would inactivate Bt spores but not affect its toxicity. In the radiation dosage range of 10-15 kilogray, no viable spore formation and no significant reduction of the efficiency of Bt against lepidopteran larvae were observed. However, further sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results show that the components of the protoxin are affected by gamma radiation and that some bands are absent after treatment compared with the controls; the change in the protoxin band pattern depends on the type of Bt strain. Furthermore, the spore crystal structure of three Bt strains was studied with scanning electron microscopy and transmission electron microscopy. The results show that there are no changes in the size or shape of the treated Bt spores and crystals compared with the controls. The use of gamma radiation is effective to inactivate the spores of engineered Bt strains while preserving stable Bt toxicity against the target insect larvae.

Papain incorporated chitin dressings for wound debridement sterilized by gamma radiation

Wound debridement is essential for the removal of necrotic or nonviable tissue from the wound surface to create an environment conducive to healing. Nonsurgical enzymatic debridement is an attractive method due to its effectiveness and ease of use. Papain is a proteolytic enzyme derived from the fruit of Carica papaya and is capable of breaking down a variety of necrotic tissue substrates. The present study was focused on the use of gamma radiation for sterilization of papain dressing with wound debriding activity. Membranes with papain were prepared using 0.5% chitin in lithium chloride/dimethylacetamide solvent and sterilized by gamma radiation. Fluid absorption capacity of chitin–papain membranes without glycerol was 14.30±6.57% in 6h. Incorporation of glycerol resulted in significant (p<0.001) increase in the absorption capacity. Moisture vapour transmission rate of the membranes was 4285.77±455.61g/m2/24h at 24h. Gamma irradiation at 25kGy was found suitable for sterilization of the dressings. Infrared (IR) spectral scanning has shown that papain was stable on gamma irradiation at 25–35kGy. The irradiated chitin–papain membranes were impermeable to different bacterial strains and also exhibited strong bactericidal action against both Gram-positive and Gram-negative bacteria. The fluid handling characteristics and the antimicrobial properties of chitin–papain membranes sterilized by gamma radiation were found suitable for use as wound dressing with debriding activity.

&amp;lt;i&amp;gt;In Vitro&amp;lt;/i&amp;gt; Evaluation of Gamma Irradiation on a Gel Formulation of Cratylia Mollis: Rheological Proporties and Microbiological Control

Lectin Cramoll-1,4, obtained from Cratylia mollis seeds (beans camaratu) was structurally characterized, biologically and pharmacologically, but its use as a biopharmaceutical is not well documented. The objective of this study is to propose a biopharmaceutical formulation lectin Cramoll-1,4, test their hemagglutinating properties in vitro as well as the use of gamma radiation as a continuous process of decontamination formulation. It was made of the extraction and purification Cramoll-1,4, was developed a gel formulation using Carbopol? as a vehicle, at concentrations of 50, 100, 200, 300 and 600 μg was irradiated with 60Co gamma rays in a dose of 7.549 kGy·h–1. The proposed formulation at a concentration of 300 μg produced an increase in the hemagglutinating units Cramoll-1,4 due to the synergistic effect caused by gamma radiation. Considering the diverse use of lectins, specific molecular and structural factors, as well as changes resulting from its formulation, concentration, irradiation and route of administration is of utmost importance to continue the studies in vitro, for subsequent application in vivo to characterize the physiological and molecular processes involved in the response and cellular effects.

Effect of low temperature between fractionated-dose irradiation doses on mating of the West Indian sweetpotato weevil, Euscepes postfasciatus (Coleoptera: Curculionidae)

The effectiveness of the sterile insect technique (SIT) depends on the ability of released sterile males to mate with and inseminate wild females, but the use of gamma radiation to induce sterility negatively affects both somatic and reproductive cells of the sterilized insects. Recently, the effectiveness of fractionated-dose irradiation (FI), in which a sterilizing dose is delivered over time in a series of small irradiations, has been demonstrated in the West Indian sweetpotato weevil Euscepes postfasciatus (Fairmaire). FI improves male mating propensity compared with acute irradiation; however, this renewed technique takes a long time (72 h in the present circumstances) compared with the traditional technique (approximately 20 min) using single-dose irradiation (150 Gy) to fully sterilize this weevil. The extra time required by FI might negatively affect the quality of released sterile males, because weevils expend limited resources, such as metabolic energy or sperm, in mating freely in this period. We evaluated whether the temporal storage of weevils at low temperature (5°C and 15°C) improves the quality of sterile males compared with the normal condition (25°C). Temporal storage at low temperature in FI improves male mating propensity. For example, the sexually active phase of males exposed to 15°C was 18 days at least after irradiation. This period was longer than that of normal males (14 days). Meanwhile, this manner delayed male reproductive development and temporarily reduced mating competitiveness ability. If considering the long active phase of sterile males exposed to 15°C, these disadvantage would be cancelled out. We discuss the advantage of FI with temporal storage at low temperature in the eradication program using SIT for E. postfasciatus.

Changes in structural characteristics of LLDPE functionalized with DEM using gamma-irradiation

This work studies the structural changes produced by gamma-radiation as a source of free radicals for functionalizing linear low-density polyethylene (LLDPE) with diethyl maleate (DEM). The grafting of the DEM onto the LLDPE was carried out in solution using gamma-rays from a 60Co source in air at room temperature, at a dose rate of 4.8 kGy/h and absorbed doses ranging from 15 to 400 kGy. The increase in the dose produced a higher concentration of free radicals and hence a higher grafting degree. The effects of DEM concentration are only perceptible at absorbed doses higher than 50 kGy. For a concentration of 30% DEM, the functionalization degrees ranged from 0.04 to 0.44 mol%. The use of gamma radiation modifies the structural and physical characteristics of the functionalized polyethylene with respect to the unmodified one, because, depending on the dose, the effects of gamma-rays can lead to crosslinking of materials with decreased flowability. The effects of gamma-radiation onto the molecular structure and molecular weight distribution of LLDPE are mitigated by the presence of DEM, due to the competition with the chain scission, branching and crosslinking reactions, for the consumption of the free radicals. The results provided by applying the successive self-nucleation and annealing technique allow reaching an unequivocal conclusion: that the free radicals formed by gamma radiation for the DEM insertion and main chain modifications are preferentially generated in the secondary carbons of the more regular CH2 sequences. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Prolongation of the effective copulation period by fractionated‐dose irradiation in the sweet potato weevil, Cylas formicarius

AbstractThe sterile insect technique (SIT), based on the principles of population and behavioral ecology, is widely used to suppress or eradicate target pest insect populations. The effectiveness of SIT depends on the ability of released sterile males to mate with and inseminate wild females; however, the use of gamma radiation to induce sterility negatively affects both somatic cells as well as reproductive cells. Consequently, sterilization by irradiation drastically diminishes mating performance over time. It is well known that fractionated‐dose irradiation, in which a sterilizing dose is delivered via a series of smaller irradiations, reduces radiation damage. In the present study, we evaluated the effect of fractionated‐dose irradiation on fertility, longevity, and mating propensity in Cylas formicarius (Summers) (Coleoptera: Brentidae) for 16 days after irradiation. Fractionated‐dose irradiation with 200 Gy induced full sterility regardless of the number of radiation doses. Although the mating propensity of males sterilized by a single 200 Gy dose (the current standard of the Okinawa Prefecture SIT program) was equal to that of non‐irradiated weevils for the first 6 days, the mating propensity of males sterilized by a series of three doses was maintained for at least the first 12 days. These results demonstrated that fractionated‐dose irradiation can be highly advantageous in C. formicarius eradication programs.

Fractionated irradiation improves the mating performance of the West Indian sweet potato weevil Euscepes postfasciatus

1 The sterile insect technique (SIT) is widely used to suppress or eradicate target pest insect populations. 2 The effectiveness of SIT depends on the ability of released sterile males to mate with and inseminate wild females. The use of gamma radiation to induce sterility, however, negatively affects both somatic cells as well as reproductive cells. Consequently, mating performance of sterilized individuals decreases drastically over time. The mating propensity of sterilized Euscepes postfasciatus (Fairmaire) males irradiated with a single dose of 150 Gy (the current standard of the Okinawa Prefecture SIT programme) is equal to that of non-irradiated weevils for the first 6 days. 3 Fractionated irradiation, in which a sterilizing dose is delivered over time in a series of smaller irradiations, reduces the damage of irradiation in insects. In the present study, we evaluated the effect of fractionated irradiation on male fertilization ability, longevity and mating propensity of E. postfasciatus for a period of 16 days after irradiation. 4 Although fractionated irradiation totalling 150 Gy was found to induce full sterility regardless of the number of individual doses, the mating propensity of male weevils sterilized by fractionated irradiation was maintained for the first 12 days. These results demonstrate that fractionated irradiation can be highly advantageous in programmes aimed at eradication of E. postfasciatus.

Assessment of Effect of Partial Sterility on Mating Performance in Sweetpotato Weevil (Coleoptera: Curculionidae)

The sterile insect technique (SIT) is widely used to suppress or eradicate target pest insect populations. Although the effectiveness of SIT depends on the ability of released sterile males to mate with and inseminate wild females, the use of gamma radiation to induce sterility negatively impacts reproductive cells as well as somatic cells. Consequently, sterilization by irradiation drastically diminishes mating performance over time. In the current study, we evaluated the effect of irradiation dose intensity on fertility, mating propensity, and mating competitiveness in sweetpotato weevil, Cylas formicarius elegantulus (Summers) (Coleoptera: Curculionidae), for 16 d after irradiation. Although the mating propensity of males irradiated with 200 Gy, the dose currently used to induce complete sterility of C. f. elegantulus in the SIT program in Okinawa Prefecture, was equal to that of nonirradiated weevils for the first 6 d, the mating propensity of males irradiated with doses between of 75 and 150 Gy was maintained for the first 12 d. The potential fertilization ability of weevils was highly depressed compared with the control weevils, even in those treated with 75 Gy. Mating performance was severely compromised in weevils that were irradiated with a dose of 100 Gy or more. These results demonstrate that partial sterilization can be highly advantageous in eradication programs for the sweetpotato weevil. We discuss the advantages of the application of partial irradiation in insect eradication programs.