kGy Gamma Irradiation Research Articles

Effects of gamma irradiation on chemical and sensory characteristics of natural hazelnut kernels

In present study, natural hazelnut kernels were treated with, 0.5, 1 and 1.5kGy of gamma irradiation. The irradiated and untreated hazelnuts were stored at 20±0.5°C and 55–60% relative humidity for 18m. After irradiation, 0.5, 1 and 1.5kGy doses of gamma irradiation significantly increased the total fat values (p<0.05) and this value decreased during the storage. After treatment, free fatty acid values were similar in untreated and treated hazelnuts. After 6m of storage, irradiated and untreated hazelnuts had less than 1% free fatty acid values. However, control and 1.5kGy yielded higher than 1% free fatty acid after 9m of storage. After irradiation, peroxide values increased proportionally to the dose but the increase was not significant. Peroxide values increased during the storage period (p<0.05). Control and 0.5kGy-treated hazelnuts had maximum peroxide values after 9m of storage, while 1kGy and 1.5kGy-treated hazelnuts had maximum levels after 12m of storage. Applied doses did not cause any significant changes in crude protein, water activity (aw), crude cellulose and moisture content of hazelnuts (p>0.05). Storage period significantly affected the water activity and crude cellulose (p<0.05). Irradiation doses didn’t affect the L*, a* and b* values (p>0.05), but storage period significantly affected the color values (p<0.05). At the end of storage period, L* and vitamin E values decreased proportionally to the dose.The 0.5kGy-treated hazelnuts had the lowest free fatty acid and peroxide values and such a case also reflected in sensory analyses. Furthermore, these hazelnuts had the highest vitamin E value after the control group. Application of 0.5kGy gamma irradiation seems to be acceptable for natural hazelnut kernels, but food safety issues have to be evaluated in order to recommend its application as a useful conservation alternative.

Inhibitory effect of gamma irradiation and its application for control of postharvest green mold decay of Satsuma mandarins

Gamma irradiation has been shown to be effective for the control of postharvest fungi in vitro, but little is known regarding antifungal action, responses to gamma irradiation, and its application to fresh produce. Gamma irradiation was evaluated for its in vitro and in vivo antifungal activity against Penicillium digitatum on Satsuma mandarin fruits. Green mold was inhibited in a dose-dependent manner. Gamma irradiation showed a complete inhibition of spore germination, germ tube elongation, and mycelial growth of P. digitatum, particularly at 1.0kGy. To further investigate the mechanisms by which gamma irradiation inhibits fungal growth, the membrane integrity and cellular leakage of conidia were tested, indicating that gamma irradiation results in the loss of plasma membrane integrity, causing the release of intracellular contents such as soluble proteins. In vivo assays demonstrated that established doses can completely inhibit the growth of fungal pathogens, but such high doses cause severe fruit damage. Thus, to eliminate the negative impact on fruit quality, gamma irradiation at lower doses was evaluated for inhibition of P. digitatum, in combination with a chlorine donor, sodium dichloro-s-triazinetrione (NaDCC). Interestingly, only a combined treatment with 0.4kGy of gamma irradiation and 10ppm of NaDCC exhibited significant synergistic antifungal activity against green mold decay. The mechanisms by which the combined treatment decreased the green mold decay of mandarin fruits can be directly associated with the disruption of cell membrane of the fungal pathogen, which resulted in a loss of cytoplasmic material from the hyphae. These findings suggest that a synergistic effect of combining treatment with gamma irradiation with NaDCC has potential as an antifungal approach to reduce the severity of green mold in mandarin fruits.

Flavisolibacter tropicus sp. nov., isolated from tropical soil.

A Gram-stain-negative, non-motile, deep yellow, rod-shaped bacterium, designated strain LCS9T, was isolated from a soil sample at the tropical zone within the Ecorium of the National Institute of Ecology in Seocheon, central-western Korea. 16S rRNA gene sequence analysis showed that strain LCS9T clustered with members of the genus Flavisolibacter of the family Chitinophagaceae, phylum Bacteroidetes. Sequence similarities between strain LCS9T and the type strains of the genus Flavisolibacter ranged from 94.6 to 94.9 %. Strain LCS9T grew at 10-37 °C (optimum, 25 °C) and at pH 6.0-10.0 (optimum, pH 7); was positive for catalase and oxidase; and negative for nitrate reduction and production of indole. Cells showed pigment absorbance peaks at 451 and 479 nm, and had 0.03 % survival following exposure to 3 kGy gamma radiation. Strain LCS9T had the following chemotaxonomic characteristics: the major quinone was menaquinone-7 (MK-7); the major fatty acids were iso-C15 : 0 and iso-C17 : 0 3-OH; polar lipids included phosphoatidylethanolamine, an unidentified aminophospholipid, unidentified aminolipidsand unidentified lipids. The DNA G+C content was 39.4 mol%. Based on polyphasic analysis, the type strain LCS9T (=KCTC 42070T=JCM 19972T) represents a novel species for which the name Flavisolibacter tropicus sp. nov. is proposed. Radiation resistance in the genus Flavisolibacter has not been reported to date, and so this is the first report of low-level radiation resistance of a member of the genus.

Microbial decontamination of gamma irradiated black tea and determination of major minerals in black tea, fresh tea leaves and tea garden soil

The purpose of this research was to establish an effective dose of gamma irradiation to eliminate any possible bacterial contamination as well as assess the levels of essential major elements [sodium (Na), potassium (K), calcium (Ca), magnesium (Mg) and iron (Fe)] present in black tea. The samples were compared to fresh tea leaves and soil from the tea gardens of two distinct tea cultivating regions (Sylhet and Moulvibazar) in Bangladesh. Maximum coliform bacterial contaminants (4.0 × 102 cfu/g) were completely eliminated following an irradiation dose of 2.5 kGy, whereas a viable bacterial load of 9.0 × 103 cfu/g was completely eliminated at 5.0 kGy. Major elements were present at higher concentrations in black tea samples originating from Sylhet compared to those from Moulvibazar. Among the analyzed elements, only Na and Fe were present at higher concentrations in the fresh tea leaves from Sylhet, whereas K, Ca and Mg were observed at higher concentrations in the tea leaves from Moulvibazar. The amount of each mineral in the black tea is acceptable for daily intake and is safe for consumption. It is concluded that black tea from Bangladesh is a rich source of minerals and could be free of microbial contamination after receiving 5.0 kGy of gamma radiation.

Optical Properties Changes of Ternary Glasses: Gamma Irradiation Effect

Research on tellurite based glass has become important because of it potential in photonic and shielding material. In this work, the changes of the optical properties of ternary tellurite glasses when radiated with 25kGy gamma ray dose were studied. Five glass samples, with composition [(TeO2)70 (B2O3)30]100-x (Bi2O3)x (where x = 5, 10, 15, 20 and 25 mol%) were prepared by melt quenching technique. The optical properties were studied by UV-Visible absorption. The X-Ray Diffraction (XRD) spectra result shows that all glass samples fit the amorphous state. The Fourier Transform Infrared Spectroscopy (FTIR) was used to explore the structural bonding in the prepared glass samples due to exposure. Gamma irradiation causes a profound change in the peak intensity as shown by FTIR spectra which is due to the breaking of the network bonding. Before gamma irradiation, the optical band gap, Eg value decreased from 2.50 eV to 2.30 eV with the addition of Bismuth content. The value kept decreasing (from 2.18 eV to 2.05 eV) following exposure to 25 kGy gamma irradiation due to the increase of non-bridging oxygen (NBO) and the increase of defect in the glass. The finding suggest that the glass with high content of Bi2O3 (25 Bi) give smallest Eg and show less changes (less defect) in FTIR spectra after gamma irradiation which indicate that this glass is more resistant to 25 kGy gamma irradiation dose compared to other glasses.

Effect of Gamma Radiation on Growth and Metabolic Activities of Arthrospira platensis

This work aimed to study the influence of gamma radiation on the growth and production of some active substances of Arthrospira platensis. Biomass production was significantly inhibited (p ≤ 0.05) by 21 and 34%, with respect to the control at 2.0 and 2.5 kGy, respectively. Chlorophyll-a content showed 11% reduction at 2.5 kGy compared to the control. As a result of growth and Chl-a inhibition, chlorophyll productivity recorded a continuous significant decrease below the control in the cells exposed to 1, 1.5, 2 and 2.5 kGy by 8, 12, 15 and 25%, respectively after 15 days of incubation. In addition, phycobillins productivity showed significant decrease by 10 and 36% below the control at 2 and 2.5 kGy of gamma radiation, respectively. Protein production decreased significantly by 24% at 1.5 kGy; low doses of gamma irradiation (0.5, 1.0 and 1.5 kGy) induced carbohydrate production by 106, 246 and 146%, respectively. Lipid content increased significantly over the control at 0.5 kGy of gamma irradiation by 22%, which was decreased at higher doses. Interestingly, carotenoid productivity showed significant increase at all used gamma doses up to 155% over the control.

The effects of terminal sterilization upon the biological activity and stiffness of extracellular matrix hydrogels

The effects of terminal sterilization upon the biological activity and stiffness of extracellular matrix hydrogels

Inactivation of murine norovirus-1 in the edible seaweeds Capsosiphon fulvescens and Hizikia fusiforme using gamma radiation

This study investigated the effects of gamma radiation (3–10 kGy) upon the inactivation of murine norovirus-1 (MNV-1), a human norovirus (NoV) surrogate. The edible green and brown algae, fulvescens (Capsosiphon fulvescens) and fusiforme (Hizikia fusiforme), respectively, were experimentally contaminated with 5–6 log10 plaque forming units (PFU)/ml MNV-1. The titer of MNV-1 significantly decreased (P < 0.05) as the dose of gamma radiation increased. MNV-1 titer decreased to 1.16–2.46 log10 PFU/ml in fulvescens and 0.37–2.21 log10 PFU/ml in fusiforme following irradiation. However, all Hunters (‘L’, ‘a’ and ‘b’) and sensory qualities (appearance, color, flavor, texture and overall acceptability) were not significantly (P > 0.05) different in both algae following gamma radiation. The Weibull model was used to generate non-linear survival curves and to calculate Gd values for 1, 2, and 3 log10 reductions of MNV-1 in fulvescens (R2 = 0.992) and fusiforme (R2 = 0.988). A Gd value of 1 (90% reduction) corresponded to 2.89 and 3.93 kGy in fulvescens and fusiforme, respectively. A Gd value of 2 (99% reduction) corresponded to 7.75 and 9.02 kGy in fulvescens and fusiforme, respectively, while a Gd value of 3 (99.9% reduction) in fulvescens and fusiforme corresponded with 13.83 and 14.93 kGy of gamma radiation, respectively. A combination of gamma radiation at medium doses and other treatments could be used to inactivate ≥3 log10 PFU/ml NoV in seaweed. The inactivation kinetics due to gamma radiation against NoV in these algae might provide basic information for use in seaweed processing and distribution.

Antifungal effect of gamma irradiation and sodium dichloroisocyanurate against Penicillium expansum on pears

Gamma irradiation (GI) was evaluated for its in vitro and in vivo antifungal activity against Penicillium expansum on pear fruits. GI showed a complete inhibition of spore germination, germ tube elongation and mycelial of P. expansum, especially 1·8 kGy. GI affected the membrane integrity and cellular leakage of conidia in a dose-dependent manner. Furthermore, the leakage of protein and sugar from mycelia increased along with the dose. GI was evaluated at lower doses in combination with a chlorine donor, sodium dichloro-s-triazinetrione (NaDCC), to examine the inhibition of P. expansum. Interestingly, only a combined treatment with 0·2 kGy of GI and 70 ppm of NaDCC exhibited significant synergistic antifungal activity. The mechanisms by which the combined treatment decreased the blue mould decay of pear fruits could directly associated with the disruption of the cell membrane of the fungal pathogen, resulting in a loss of cytoplasmic materials from the hyphae. Gamma irradiation (GI) is used as an effective nonchemical approach to inactive pathogens. This study investigated the antifungal effect of gamma irradiation and its combined treatment with a chlorine donor on this fungal pathogen, both in vitro and in vivo. This study emphasized that the integration of low-dose GI and a chlorine donor, NaDCC, exhibited a significant antifungal effect, and that its mechanisms are directly associated with membrane integrity of fungal spores, promising that GI has the potential to be an antifungal approach.

Yumurta Tavuğu Yemlerinde Gama Işınlanmış Buğday ve Arpa Kullanılmasının Yumurta Verim Kriterleri ve Kalitesi Üzerine Etkileri

In this study, the effect of using gamma irradiated barley and wheat 0, 10 and 100 kiloGray (kGy) and enzyme supplementation on the egg product criterions and external and internal egg quality was examined. In this experiment, 36 weeks old, 324 Brown Nick laying hens were used for ten week. The study was a randomized complete block design with 9 dietary treatments within 6 blocks of 54 pens each 6 birds per pen. Although egg weight was not significantly affected by gamma irradiation; enzyme supplementation of barley based diet significantly increased egg weight compared to barley control group. As egg mass production was considered, enzyme and 100 kGy gamma irradiation significantly improved the egg mass production compared to barley control. The feed conversion ratio was significantly improved by using gamma irradiated barley and enzyme in barley based diets (P

Grafting of Vinyl Pyrrolidone/Styrene onto Ethylene/Chlorotrifluoroethylene Membrane for Proton ExchangeMembrane Fuel Cell

Simultaneous gamma irradiation was proved to be an effective tool for ethylene/ chlorotrifluoroethylene grafting by styrene and vinyl pyrrolidone with different ratios. It was found that; the optimum grafting yield was 81% by using 40 kGy gamma irradiation dose when the binary monomers ratio was 1:1 (styrene: vinyl pyrrolidone). The grafted membranes were investigated for chemical structure by FT-IR and thermal properties by thermal gravimetric analysis. The mechanical properties were studied by measuring tensile strength while morphological structure was characterized by scanning electron microscope. The membranes’ free volume sizes were determined using positron annihilation lifetime spectroscopy (PALS). Ion exchange capacity, water uptake and membranes thickness were investigated and proton conductivity was evaluated. The optimum temperature for attaining the maximum fuel cell performance was at 75°C while it reduced by decreasing the temperature to 50°C or increasing it to 85°C. The fuel cell performance based highest yield of the grafted membrane was more durable than compressed Nr.118 (commercial membranes) up to 450hours.

Effects of Gamma and Electron Beam Radiation on Brazil Nuts Artificially Inoculated with Aspergillus flavus

The aim of this study was to evaluate the effects of gamma radiation (GR) and electron beam (EB) on Brazil nut samples contaminated with Aspergillus flavus. Fifty samples were spread with an A. flavus suspension and incubated at 30°C and a relative humidity of 93%. After 15 days of incubation, mycobiota and aflatoxin analysis were performed. The samples were divided into three groups (control, group 1, and group 2) that received radiation doses of 0 kGy (control) and 5 and 10 kGy each of GR and EB (groups 1 and 2). Noninoculated samples were irradiated with the same doses for sensory evaluation. The results showed that after 15 days of incubation, the average water activity of the samples was 0.80. The irradiation with GR and EB at doses of 5 and 10 kGy was able to eliminate A. flavus in Brazil nut samples. Aflatoxin analysis showed that EB doses of 5 and 10 kGy reduced aflatoxin B1 levels by 53.32 and 65.66%, respectively, whereas the same doses of GR reduced the levels of this toxin by 70.61 and 84.15% compared with the level in the control groups. Sensory evaluation demonstrated that the texture and odor of irradiated Brazil nut samples were acceptable. The taste evaluation indicated that 5 kGy of GR was judged acceptable. The results highlight that both irradiation processes (5- and 10-kGy doses) showed efficiency in A. flavus and aflatoxin elimination. GR and EB treatments resulted in some alterations in the sensory attributes of samples with the doses used in this study; however, Brazil nut samples irradiated with 5-kGy GR doses were considered acceptable.

Enhancement of Lipase Biosynthesis by Aspergillus Niger Using Gamma Radiation

Objectives: The present study describes the isolation, identification and screening of fugal isolates for the biosynthesis of extracellular lipase enzyme. Methodology:Thirteen fungal cultures were isolated from cotton seeds, waste cake of cotton seed oil and spent bleaching earth, samples by serial dilution method. All isolates were initially selected qualitatively on tributyrin agar plates and were shifted to the slants of PDA for maintenance and storage at 4 o C. Quantitative screening for extracellular lipase biosynthesis by isolated fungi was carried out in shake flasks and the most potent fungal isolate which producing 25 U ml-1 of enzyme was selected. The isolate was then identified on the basis of standard morphological measurements and was assigned the code Aspergillus niger ADM 110.Results:Enhanced lipase biosynthesis was observed at 25 °C, pH 7, 1.0 ml (4.60 × 10 7 ) of spore inoculum and after 72 h of incubation. Olive oil 5 % was observed as the most effective carbon source and yeast extract 5.0 % as the most effective nitrogen source for lipase biosynthesis. The optimum shaking value was 200 rpm. Aspergillus niger ADM 110 was subjected to Gamma radiation in order to improve its lipolytic potential. Conclusion:Using the optimized conditions, maximum lipase biosynthesis has been obtained by using 0.14 kGy of gamma radiation with enzyme activity 53 U/ml as compared to the parent strain (unirradiated) with enzyme activity 30 U/ml.

Effect of gamma irradiation on Korean traditional multicolored paintwork

Abstract Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe 2 O 3 ), Jangdan (Minium; Pb 3 O 4 ), Whangyun (Crocoite; PbCrO 4 ), and Jidang (Rutile; TiO 2 ), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d’Eclairage (CIE) color values ( L *, a *, b *) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE * unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong.

Effect of gamma radiation on microbiological changes in dry salted ribbon fish (Lepturacanthus savala, Cuvier, 1829)

A study was conducted to determine the effects of gamma radiation on microbiological qualities of dry salted ribbon fish ( Lepturacanthus savala ) collected from fish drying yard. Results of microbiological analysis showed that total plate count in non-irradiated ribbon fish was 6.9±0.15 log cfug -1 which was significantly reduced by 1 logs at 1.0 kGy, 2 to 3 logs at 3.0 kGy and 3 to 4 logs at 5.0 kGy gamma radiation. Maximum staphylococci count was noted in non-irradiated ribbon fish (3.17±0.17 log cfug -1 ) compared to irradiated with 1.0 kGy (2.63±0.50 log cfug -1 ), 3.0 kGy (2.35±0.35 log cfug -1 ) and 5.0 kGy (1.95±0.50 log cfug -1 ) on 0 th day. At the end of experiment, the halophilic count was 4.98±0.40 log cfug -1 in control while in 5.0 kGy irradiated fish sample it was 1.49±0.49 log cfug -1 . Vibrio cholera, Salmonella and Shigella and E.coli were not detected in experimental fish samples during investigation. Total fungal count recorded was 2.48±0.03 log cfug -1 in non-irradiated ribbon fish but it was totally eliminated in 5.0 kGy irradiated fish samples. Gamma irradiation doses (1.0, 3.0 and 5.0 kGy) had no significant effect (P>0.05) on sensory properties (appearance, colour, odour and texture) of dry salted ribbon fish sample neither at zero time nor during nine month storage periods. It can be concluded that, gamma irradiation dose of 3.0 and 5.0 kGy had a significant (P<0.05) effects on decreasing microbial load and improve the microbiological safety of dry salted ribbon fish without any adverse effects on their sensory quality.

Effect of gamma irradiation and its convergent treatment for control of postharvest Botrytis cinerea of cut roses

Postharvest diseases cause considerable losses to harvested crops. Among them, gray mold (Botrytis cinerea) is a major problem of exporting to cut rose flowers into Korea. Irradiation treatment is an alternative to phytosanitary purposes and a useful nonchemical approach to the control of postharvest diseases. Gamma irradiation was evaluated for its in vitro and in vivo antifungal activity against B. cinerea on cut rose varieties, ‘Shooting Star’ and ‘Babe’. The irradiating dose required to reduce the population by 90%, D10, was 0.99 kGy. Gamma irradiation showed complete inhibition of spore germination and mycelial growth of B. cinerea, especially 4.0 kGy in vitro. Antifungal activity of gamma irradiation on rose B. cinerea is a dose-dependent manner. A significant phytotoxicity such as bent neck in cut rose quality was shown from gamma irradiation at over 0.4 kGy (p<0.05) in both varieties. Although there is no significant difference in both varieties for fresh weight, in the case of flower rate, ‘Babe’ shows more sensitivity than ‘Shooting Star’. In vivo assays demonstrated that established doses in in vitro, over 4 kGy, could completely inactive fungal pathogens, but such high doses can cause severe flowers damage. Thus, to eliminate negative impact on their quality, gamma irradiation was evaluated at lower doses in combination with an eco-friendly chemical, sodium dichloroisocyanurate (NaDCC) to examine the inhibition of B. cinerea. Intriguingly, only the combined treatment with 0.2 kGy of gamma irradiation and 70 ppm of NaDCC exhibited significant synergistic antifungal activity against blue mold decay in both varieties. Together, these results suggest that a synergistic effect of the combined treatment with gamma irradiation and NaDCC can be efficiently used to control the postharvest diseases in cut rose flowers, and will provide a promising technology for horticulture products for exportation.

New insights into the structural characteristics of irradiated crotamine.

BackgroundSince ionizing radiation has the potential to alter the molecular structure and affect the biological properties of biomolecules, it has been successfully employed to attenuate animal toxins. The present study aimed to characterize the structural modifications on irradiated crotamine, a toxin from Crotalus durissus terrificus venom, using circular dichroism (CD), fluorescence, Fourier transformed infrared spectroscopy (FTIR), atomic force microscopy (AFM) and differential scanning calorimetry (DSC).MethodsA combination of size exclusion and ion-exchange chromatography was used to purify the peptide using crude venom. The pure toxin was then submitted to 2 kGy gamma irradiation doses from a cobalt-60 source. Native and irradiated crotamine were analyzed using a fluorescence spectrophotometer. Wavelength was fixed at 295 nm and fluorescence emission scans were collected from 300 to 400 nm. CD and FTIR techniques were used to identify the secondary structure of both samples. DSC analyses were performed at a starting temperature of 20 °C up to a final temperature of 90 °C. AFM provided a 3D profile of the surfaces of both crotamine forms adsorbed on mica.ResultsFluorescence spectroscopy showed that the quantum yield of the irradiated form decreased. CD spectra of native and irradiated crotamine solutions showed differences between the samples in wavelength, indicating that irradiation induced a transition of a small portion of the random coil regions towards an α-helical conformation. FTIR and CD showed that the native and irradiated crotamine spectra were different with regard to secondary structure. The thermodynamic analysis showed that irradiation caused changes in the calorimetric profile and CD showed that temperature-induced changes also occur in the secondary structure. Finally, AFM showed the possible formation of insoluble aggregates.ConclusionsOur results indicate that irradiation leads to progressive changes in the structure of the toxin, which could explain a decrease in myotoxic activity.

Gamma radiation control quality and lignification of bamboo shoots (Phyllostachys praecox f. prevernalis.) stored at low temperature

Bamboo shoots are highly nutritious but possess poor shelf life after harvest due to rapid decline of tenderness mostly result from lignification processes. Present investigation was performed to evaluate the potential of gamma radiation as a postharvest technology to preserve bamboo shoots. The effects of 0.5kGy gamma radiation on quality and lignification of bamboo shoots during storage at 2°C were investigated. The results showed that gamma radiation reduced the decay rate of bamboo shoots by 71% at the end of storage. It also significantly retarded ethylene production through controlling the activities of ACC synthase (ACS) and ACC oxidase (ACO), which may contribute to inhibition of lignin synthesis. Meanwhile, gamma radiation decreased the activities of phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD) and peroxidase (POD), which are associated with lignin accumulation, thus reduced lignin content by 12.5% than that of the control after twenty-eight days of storage. These results demonstrated the potential of the gamma radiation as a promising postharvest technique to maintain the quality and inhibit the lignification of bamboo shoots.

Studies on the gamma-Irradiated Polyvinyl Alcohol (PVA) Blended Gelatin Films

Different concentrations of PVA blended Gelatin were taken for grafting under γ-radiation. Better grafting means better cross-linking of polymer. We observed the effect of concentration of polymers and the effect of radiation doses. Various physico-mechanical and morphological properties like tensile strength (TS), elongation at break (Eb), FTIR, Scanning Electron Microscopy (SEM) of films were observed. For untreated (virgin) Film, radiation doses were optimized for such types of properties. By casting process Gelatin-based polyvinyl alcohol (PVA) films were prepared in different ratios. These films were irradiated under gamma radiation (60Co) at different doses (0.5-5 kGy). The mechanical properties of these films were evaluated. It was found that 95% gelatin +5% PVA film exhibited the highest tensile strength (TS) value at 0.5 kGy gamma radiation (51 MPa), which was 46% higher than that of nonirradiated films.

Attempts to Create Wheat (Triticum aestivum L.) Superior High-Yielded Variety through Mutation Breeding

Experiments to determine radiation dose effective for increasing wheat genetic diversity has been conducted from March to May 2015. Wheat seeds radiation was carried out at Research Center and PATIR BATAN, South Jakarta, followed by wheat growth screening at greenhouse of PATPKP UNAND at Alahan Panjang, Municipality of Solok, the Province of West Sumatra. Wheat genotypes of IS-Jarissa dan GURI 6 UNAND were subjected to gamma radiation as follow: 0 . 1; 0 . 2; 0 . 3; 0.4; 0.5; 0.6; 0.7; 0.8; 0.9; 1. 0 kGy ; and 0 kGy as control treatment. The wheat seeds were then grown in a mixture of soil and cow manure (3:1) w/w in a greenhouse. Data demonstrated that increasing the radiation doses resulted in decreasing in wheat growth. The effective doses of gamma radiation were 0.2 and 0.3 kGy. No wheat grown observed from the treatment groups of 0.5kGy gamma radiation and higher.