Ethylene Oxide Fumigation Research Articles

Effect of temperature and relative humidity on ethylene oxide inactivation of Salmonella and Enterococcus faecium NRRL B-2354 on chia seeds and its influence on the quality of seeds

Ethylene oxide (EtO) sterilization is commonly used by the food industry to inactivate pathogens in spices, but its efficacy on edible seeds, a high-risk food commodity, remains unexplored. This study aimed to evaluate the antimicrobial efficacy of EtO gas on chia seeds and assess the impact of processing parameters on microbial reduction, byproduct formation, and seed quality. Further, Enterococcus faecium NRRL B-2354 was evaluated for its suitability as a surrogate for Salmonella. Chia seeds were inoculated with a cocktail of five strains of Salmonella enterica or E. faecium. The inoculated sample was treated with EtO (735.3 mg/L) at different combinations of relative humidity (30, 40, and 50%) and temperature (46, 53, and 60 °C) for exposure times ranging from 2 to 120 min. The results showed that EtO treatment effectively reduced the bacterial populations on chia seeds, with the inactivation trend following a non-linear pattern that was described well by the Weibull model. The treatment time required for a 5-log reduction of Salmonella was less than 10 min at 50% RH and 53–60 °C. Exposure of chia seeds to EtO for 2 min at 50% RH gave 3.15, 3.59, and 3.87 log reductions at 46, 53, and 60 °C, respectively. E. faecium was found to be a reliable surrogate for Salmonella during EtO treatment. The modified Bigelow model developed based on Weibull model parameters could be used to predict Salmonella inactivation (RMSE = 0.73 min) and E. faecium inactivation (RMSE = 0.87 min) on chia seeds during EtO treatment. Fatty acid composition, protein content, color, and germination ability of chia seeds were not impacted significantly (P > 0.05) by EtO fumigation. These findings suggest that EtO gas can effectively inactivate Salmonella on chia seeds while preserving their viability and quality.

Comparative analysis of 3 pollen sterilization methods for feeding bumble bees.

Pollen is an essential component of bee diets, and rearing bumble bees (Bombus spp.) for commercial use necessitates feeding pollen in mass quantities. This pollen is collected from honey bee (Apis mellifera L.) colonies because neither an artificial diet nor an economical, large-scale pollen collection process from flowers is available. The provenance of honey bee-collected pollen is often unknown, and in some cases has crossed international borders. Both deformed wing virus (DWV) and the fungal pathogen Ascosphaera apis (Claussen) Olive & Spiltoir (cause of chalkbrood disease); occur in honey bee-collected pollen, and infections have been observed in bumble bees. We used these pathogens as general surrogates for viruses and spore-forming fungal diseases to test the efficacy of 3 sterilization methods, and assessed whether treatment altered pollen quality for the bumble bee. Using honey bee-collected pollen spiked with known doses of DWV and A. apis, we compared gamma irradiation (GI), ozone fumigation (OZ), and ethylene oxide fumigation (EO) against an untreated positive control and a negative control. Following sterilization treatments, we tested A. apis spore viability, detected viral presence with PCR, and tested palatability to the bumble bee Bombus impatiens Cresson. We also measured bacterial growth from pollens treated with EO and GI. GI and EO outperformed OZ treatment in pathogen suppression. EO had the highest sterilizing properties under commercial conditions and retained palatability and supported bee development better than other treatments. These results suggest that EO sterilization reduces pathogen risks while retaining pollen quality as a food source for rearing bumble bees.

Influence of germicidal ultraviolet radiation UV-C on the quality of Apiaceae spices seeds

BackgroundSpices are susceptible to surface microbial contamination. Countries’ ban on ethylene oxide fumigation due to possible residual toxicity encouraged the usage of irradiation. Surface sterilization with low doses of ultraviolet radiation has been extensively researched as a safe, eco-friendly, and fast route. This study examines the quality of Apiaceae spices for consumption, including anise, fennel, caraway, and cumin, in response to germicidal ultraviolet radiation using a developed sterilization unit.MethodsThe influence of UV-C (254 nm, 10.5 mW/cm2) on the fungal and microbial count, germination percentage, respiration rate, phenolic content, essential oil, and the activity of antioxidant enzymes was investigated at exposure durations of 0–45 min in increments of 5 min. The treated seeds were packed in polyethylene bags in a naturally aerated storage room for 30 days before the inspection.ResultsThe obtained data showed that UV-C stimulated seeds germination and increased respiration rate for all studied types. The 25 min of exposure exhibited the highest significant values compared to the control, considered a good indicator of seed vigor. In addition, UV-C exposure between 20 and 35 min promoted the accumulation of phenolic compounds and increased the oil content as a defense mechanism against radiation. Conversely, higher exposure to UV-C led to a significant reduction in phenolic and oil contents. Furthermore, the exposure to UV-C radiation enhanced the activity of antioxidant enzymes in terms of peroxidase and catalase, which progressively increased with increasing exposure durations, reached their peak at 25–30 min, and subsequently declined with extended exposure time was extended. In a similar pattern, exposure to UV-C radiation increased polyphenol oxidase activity to its highest level at 25 min, owing to the development of antioxidant protective mechanisms against oxidative stress.ConclusionUV-C irradiation in the range of 25–30 min is the most appropriate pretreatment to maintain the vitality of the examined seeds.Graphical

Effects of Sterilization Methods on the Integrity and Functionality of Covalent Mucin Coatings on Medical Devices

AbstractRecent advances in the field of biomedical materials have demonstrated that covalent mucin coatings generated on polymeric materials have the potential to greatly improve the surface properties of medical devices such as their wettability, lubricity, and resistance toward biofouling. For such biopolymer‐based coatings to be used in a medical application, sterilization of the coated devices is mandatory. However, common sterilization methods such as autoclavation, ethylene oxide fumigation, as well as γ‐ or ultraviolet‐irradiation, create harsh conditions during the device treatment, and this might compromise the structural integrity and thus functionality of macromolecular coatings. Here, it is demonstrated that covalent mucin coatings generated on medical devices made from polyvinyl chloride, polyurethane, or polydimethylsiloxane are able to withstand such treatments—albeit to different extents. Among all treatments tested, ethylene oxide fumigation is identified as the most promising method as it maintains the coatings the best. The findings imply that the beneficial properties demonstrated for mucin coatings in vitro should indeed be transferable to applications in vivo.

Pre- and postharvest factors affecting quality and safety of Pepper ( Piper nigrum L.)

Abstract The quality and safety of pepper ( Piper nigrum L.) are a function of crop management practices, harvest maturity, harvesting methods and subsequent handling after harvest, including storage conditions and processing methods. The review shows that volatile oil decreases with shade intensity (15–30%). Essential oil, oleoresin, piperine and monoterpenes (thujene, α-pinene, sabinene, limonene, α-phellandrene and linalool) increase with altitude, while β-caryophyllene and total phenol decrease with increase in altitude. Fermentation of ripe pepper fruits forms odorants (butanoic acid, 3-methylindole, and 4-methylphenol) attributing intense faecal/shed-like off-flavour white pepper powder. Low-drying temperature (≤56°C) and duration (≤3 hrs) lead to low bulk density (0.17 g/ml) and low moisture loss (31%). Excessive soaking of black peppercorns prior to mechanical decortication reduces volatile oil and increases moisture content and broken berries. Availability of heavy metals in grinding machines increases the level of heavy metals; Fe (69.8–1147 mg/kg), Pb (21.3–947 μg/kg) and V (64.1–1072 μg/kg) in pepper powder. Storing peppercorns along with other materials enhances cross-contamination of heavy metals; Pb, Cd and Cr. High moisture content (>13%) and farmers’ unawareness resulted in high (2200 to >30000 cfu/g) mycotoxins contamination. Environmental and industrial pollutants such as plasticizers, bisphenol A, polycyclic aromatic hydrocarbons and pesticides are also pepper contaminants of high merit. Radiofrequency pasteurization, vacuum-assisted steaming, ethylene oxide fumigation, atmospheric pressure plasma, dry heat sterilization, gamma-irradiation and ultraviolet-C light treatments are among strategies to enhance the quality and safety of pepper. More precautions also have to be taken to regulate the shade, drying temperature and duration, soaking duration, hygienic processing and storage in order to retain quality, minimize the risk of microbial or chemical contaminations and comply with standards.

Modeling the effect of temperature and relative humidity on the ethylene oxide fumigation of Salmonella and Enterococcus faecium in whole black peppercorn

This research investigated the effect of temperature and relative humidity (RH) conditions during ethylene oxide (EtO) fumigation for inactivation of Salmonella and Enterococcus faecium NRRL B-2354 on whole black peppercorns. Black peppercorn samples were inoculated with a five-strain Salmonella cocktail or E. faecium inoculum. EtO (735.3 mg/L) fumigation was conducted at different treatment temperatures (46, 53, and 60 °C) and different RH levels (30,40, and 50%) for the inactivation of inoculated black peppercorn samples with different exposure times (2–180 min). The temperature, RH, and exposure time exhibit significant linear effects on microbial inactivation. Bacterial inactivation during EtO fumigation was described by the Weibull model with the R2 > 0.70 and RMSE < 0.20 log CFU/g at all conditions. The concave upward trend of the Weibull model indicated a tailing effect. The inactivation data were also used to develop the response surface model as a function of temperature, RH, and exposure time to predict the reduction of Salmonella or E. faecium on whole black peppercorn during EtO fumigation. The developed models predicted log reductions with RMSE of 0.48 and 0.45 log CFU/g for Salmonella andE. faecium, respectively. Technical information for developing and validating EtO fumigation for whole black peppercorn could be estimated based on the developed model.

Processes to Preserve Spice and Herb Quality and Sensory Integrity During Pathogen Inactivation.

Selected processing methods, demonstrated to be effective at reducing Salmonella, were assessed to determine if spice and herb quality was affected. Black peppercorn, cumin seed, oregano, and onion powder were irradiated to a target dose of 8 kGy. Two additional processes were examined for whole black peppercorns and cumin seeds: ethylene oxide (EtO) fumigation and vacuum assisted‐steam (82.22 °C, 7.5 psia). Treated and untreated spices/herbs were compared (visual, odor) using sensory similarity testing protocols (α = 0.20; β = 0.05; proportion of discriminators: 20%) to determine if processing altered sensory quality. Analytical assessment of quality (color, water activity, and volatile chemistry) was completed. Irradiation did not alter visual or odor sensory quality of black peppercorn, cumin seed, or oregano but created differences in onion powder, which was lighter (higher L *) and more red (higher a*) in color, and resulted in nearly complete loss of measured volatile compounds. EtO processing did not create detectable odor or appearance differences in black peppercorn; however visual and odor sensory quality differences, supported by changes in color (higher b *; lower L *) and increased concentrations of most volatiles, were detected for cumin seeds. Steam processing of black peppercorn resulted in perceptible odor differences, supported by increased concentration of monoterpene volatiles and loss of all sesquiterpenes; only visual differences were noted for cumin seed. An important step in process validation is the verification that no effect is detectable from a sensory perspective.

Monitoring the effects of different conservation treatments on paper-infecting fungi

Fungi are among the most degradative organisms inducing biodeterioration of paper-based items of cultural heritage. Appropriate conservation measures and restoration treatments to deal with fungal infections include mechanical, chemical, and biological methods, which entail effects on the paper itself and health hazards for humans. Three different conservation treatments, namely freeze-drying, gamma rays, and ethylene oxide fumigation, were compared and monitored to assess their short- (one month, T1) and long-term (one year, T2) effectiveness to inhibit fungal growth. After the inoculation with fungi possessing cellulose hydrolysis ability — Chaetomium globosum, Trichoderma viride, and Cladosporium cladosporioides — as single strains or as a mixture, different quality paper samples were treated and screened for fungal viability by culture-dependent and -independent techniques.Results derived from both strategies were contradictory. Both gamma irradiation and EtO fumigation showed full efficacy as disinfecting agents when evaluated with cultivation techniques. However, when using molecular analyses, the application of gamma rays showed a short-term reduction in DNA recovery and DNA fragmentation; the latter phenomenon was also observed in a minor degree in samples treated with freeze-drying. When RNA was used as an indicator of long-term fungal viability, differences in the RNA recovery from samples treated with freeze-drying or gamma rays could be observed in samples inoculated with the mixed culture. Only the treatment with ethylene oxide proved negative for both DNA and RNA recovery. Therefore, DNA fragmentation after an ethylene oxide treatment can hamper future paleogenetic and archaeological molecular studies on the objects.

Descontaminação de drogas vegetais empregando irradiação gama e óxido de etileno: aspectos microbianos e químicos

A avaliacao da qualidade sanitaria de drogas vegetais, bem como a utilizacao de metodos de descontaminacao constituem importantes etapas no que se refere ao aspecto de seguranca ao consumidor, principalmente pelo fato de serem usualmente consumidas por pessoas debilitadas, por vezes imunodeprimidas. No Brasil a RDC 48/2004 menciona a pesquisa de contaminantes microbiologicos bem como o estudo da eficacia dos agentes descontaminantes. Os objetivos do presente trabalho foram avaliar os efeitos da fumigacao com oxido de etileno e da irradiacao gama sobre a carga microbiana, bem como determinar alteracoes nos constituintes quimicos em amostras de Ginkgo biloba e Paulinia cupana H.B.K. (guarana). A carga microbiana inicial foi, em media, 3,2x10(6) para microrganismos aerobicos totais e 3,0x10(5) para fungos. Ambos os metodos de descontaminacao apresentaram-se eficazes na reducao da carga microbiana. As analises por cromatografia liquida de alta eficiencia revelaram ausencia de alteracoes significativas nos teores de glicosideos flavonoidicos e cafeina, respectivamente para ginkgo e guarana.

生薬中の微生物分布と放射線殺菌効果

Herb medicines are traditional medicine in Japan and have been used for medical treatment. These herb medicines are contaminating frequently by microorganisms which has possibility to cause opportunistic diseases. Recently, hygienic standard of herb medicines become more strict than before, and it needs to decontaminate microorganisms by some treatments. However, chemical treatments such as by ethylene oxide fumigation leave toxic residues in the herbs while steam sterilization decrease medicinal components. From study on the distribution of microorganisms in 31 samples of selected herb medicines, colony forming units of total aerobic bacteria were determined to be 1.9 × 102 to 1.4 × 108per gram in 30 samples. Coliforms were also determined to be 6.9 × 102 to 4.3 × 106 per gram in 16 samples. The main aerobic bacteria were identified as Bacillus pumilus, B.circulans, B. megaterium, Erwinia, EnterobacterandAcinetobacter, whereas consisted mainly of Enterobacter in coliform counts. Molds were determined to be 6.3 × 101 to 1.9 × 105 per gram which consisted mainly Aspergillus glaucus group, A. restrictus group, A. flavus group, A. ostianus, A. phoenicis, Penicillium, Tricoderma, Rhizopus and Alternaria in 25 samples. A study on the inactivation of microorganisms at sample No. S18 showed that a gamma-irradiation dose of 20 kGy was required to reduce the total aerobic bacteria and the coliforms below a detectable level, while radiation-resistant bacteria were survived at high doses more than 10 kGy consisted withAcinetobacter and Enterobacter. Molds were inactivated below 8 kGy except Alternaria. However, a dose of 10 kGy should be effective for the sample No. S18 to reduce the spore-forming bacteria, the fecal coliforms and the molds below a detectable level per gram. On the study of inactivation of microorganisms in many samples except the No. 18, all kinds of microorganism were inactivated below a detectable level at 10 kGy irradiation.

Improvement of Hygienic Quality of White Ginseng Powders by .GAMMA.-lrradiation.

For the purpose of improving hygienic quality of white ginseng powders, the comparative effects of ethylene oxide (EO) fumigation and γ-irradiation (5 -10 kGy) on the sterilization, physicochemical properties and organoleptic quality were investigated. EO fumigation and γ-irradiation (5-10 kGy) completely eliminated the microorganisms contaminating in white ginseng powder. There was no growth of microorganisms after 7 months storage at 30°C and different relative humidities. In the physicochemical properties, ginseng saponins were considerably resistant to γ-irradiation (less than 10 kGy) and commercial EO fumigation, while sulfur-containing amino acids, reducing sugar and acidity were significantly changed by EO fumigation. EO residues were 570 ppm in the samples taken immediately after deaeration and 170 ppm in the stored samples of 8 days at 30°C, respectively. Ethylene chlorohydrin and ethylene glycol residues as the secondary products of EO were 9595 ppm immediately after deaeration and 221 ppm in the stored samples of 3 months at 30°C.

日本沿岸産フィッシュミールのサミモネラ汚染防除対策 ＩＩ 沿岸ミールのサルモネラ汚染の｀６０´Ｃｏγ線照射による防除

The decontamination of salmonellae from fish meal samples by irradiation which 60Coγ ray was examined. Sixteen strains of Salmonella were used. A composite fish meal sample was prepared by mixing with different coastal meals, and after radiation sterilization at a dose of 20 kGy 60Coγ ray, which was employed as the salmonella-free meal sample. D10 values of test strains determined in buffered saline were found to range from 0.08 to 0.36 kGy, and inactivation factors at a dose of 1 kGy ranged from 102.8 to 1013. D10 values of test strains determined in the salmonella-free meal sample ranged from 0.59 to 1.64 kGy, and the inactivation factors at a dose of 10 kGy were found to range from 106.1 to 1017. Interestingly the D10 values of salmonellae determined in fish meal samples were 10 times as much compared with those determined in buffered saline. From the commercial aspects of coastal fish meal production, destruction of salmonellae in fish meals by 60Coγ ray irradiation was found to be much more practical than other methods such as dry heating and ethylene oxide fumigation.

2-Chloroethyl Fatty Acid Esters as Indicators of 2-Chloroethanol in Black Walnuts, Seasoning Mixes, and Spices

Residues of 2-chloroethyl fatty acid esters (CEEs) and 2-chloroethanol (ECH), by-products of ethylene oxide fumigation, were determined in black walnuts, seasoning mixes, and spices. Extracts containing ECH and CEE were cleaned up by previously described procedures, and residue levels were quantitatively determined using a gas chromatograph equipped with a halogen-selective electrolytic conductivity detector. All food products that contained CEE residues also contained ECH. ECH residues ranged from less than 0.2 to 880 ppm and were less than 0.2-7 times the CEE levels found.

１０ＭｅＶ電子線を用いた放射線滅菌

Gamma-ray sterilization by 60Co source has been already popular in Japan. Many Kinds of medical plastic devices such as catheters, disposable syringes, dializers etc, has been irradiated at 60Co irradiation facilities instead of the conventional ethylene oxide fumigation method. On the other hand, improvement of the quality of electron accelerators has made it easier to take advantage of relatively high energy electrons which are profitable for radiation sterilization because of their high dose rate saving process hours and easiness of source handling and radiation control. So electron-beam sterilization is now under investigation in Japan and, partly, it will be practiced in the near future. Yet few data are available in the present situation. Especially for high energy electron beams near 10MeV, more data are necessary for practical application of electron-beam sterilization. Therefore, in this study, sensitivity of Bacillus pumilus E601, the biological standard of radiation sterilization, was examined using 10MeV electron beams from linear accelerator and sterility of the beams was also checked at each depth of plastic boards in order to get basic information for determination of sterility dose. Endospores from B. pumilus were dried on filter papers (ToyoNo.1) and irradiated by 10MeV electron beams or 60Co gamma-rays. The survival curves were shown in Fig. 1. The D values were obtained as 1.9 kGy ±0.2 for electron beams and 1.7 kGy ±0.1 for 60Co gamma-rays, both of which were similar. Electron beams could sterilize the endospores nearly uniformly till 3cm depth of plastic boards at 10MeV (Fig. 2, 3). This indicates a possibility to sterilize relatively bulky products such as dializers etc.

Ethylene Oxide Fumigation: Results and Risk. Assessment

Article Ethylene Oxide Fumigation: Results and Risk. Assessment was published on January 1, 1986 in the journal Restaurator. International Journal for the Preservation of Library and Archival Material (volume 7, issue 4).

Growth rate and aflatoxin production of Aspergillus flavus in wheat sterilized by gamma-irradiation, ethylene oxide fumigation and autoclaving

Growth rates of Aspergillus flavus L. ex Fr. and its aflatoxin production were studied at 25° and 92% e.r.h. in wheat sterilized respectively by ethylene oxide fumigation, by autoclaving and by irradiation. The fastest growth rates and in general the highest yields of aflatoxin B 1 were obtained in wheat irradiated at 1.0, 2.5 and 4.0 Mrad but some very high aflatoxin levels were also recorded for one or two samples sterilized by other methods. No simple relationship was demonstrated between growth rates and aflatoxin levels but a big decrease in growth rate was accompanied in irradiated grain by a parallel decrease in the amount of aflatoxin B 1 accumulated. Both growth rates and aflatoxin levels were variable and no differences could be established between them for samples sterilized by fumigation or autoclaving.

Ethylene Oxide Fumigation of Tobacco at Various Pressures For Control of the Cigarette Beetle13

Ethylene oxide 12% with dichlorodifluoromethane 88% at 18.1 kg/28.3 m3 under sustained vacuum for 4 h killed all stages of Lasioderma serricorne (F.) exposed in hogsheads of tobacco to depths of 30 cm. Neither air washing the hogsheads prior to fumigation to loosen the tobacco nor breaking the vacuum with air to improve penetration increased the mortality of insects deeper in the hogsheads. Also, extending the exposure period to 6 or 8 h did not increase effectiveness of the fumigation. The minimum concentration of ETO needed to kill any stage of the insect was ca. 7 mg/liter.

Effect of Processing Method on Pasturization and Nitrogen Components of Broiler Litter and on Nitrogen Utilization by Sheep

Various methods of processing broiler litter were evaluated. Treatments found to be effective for pasteurization were dry heating at 150 C for 20 min; autoclaving for 10 min or longer; dry heating at 150 C at depths of .6 or 2.5 cm following addition of 1 to 4 g of paraformaldehyde (PFA) per 100 g of litter; and ethylene oxide (ETO) fumigation for a minimum of 30 minutes. Uric acid nitrogen was lowered (P < .01) by dry heat, alone or in combination with PFA. Autoclaving and PFA addition followed by dry heat lowered (P < .01) NPN. Ammonia nitrogen was reduced (P < .01) by most of the pasteurizing treatments except autoclaving for 10 minutes. A metabolism trial was conducted with 18 wethers to study the relative effects of different litter processing methods on nitrogen utilization. Litter pasteurized by dry heating at a depth of .6 cm for 20 min, dry heating at a depth of 2.5 cm for 15 min after the addition of 2 g of PFA per 100 g of litter or fumigation with ETO at a depth of 15.2 cm for 60 min supplied 50% of the nitrogen in the respective rations. Method of processing had no significant effect on nitrogen utilization or apparent digestion coefficients. Ruminal ammonia nitrogen was higher (P < .05) for sheep fed dry heat than for those fed ethylene oxide treated litter. Acetic acid and total volatile fatty acid concentrations, expressed as µ moles/ml, were significantly (P < .05) higher for the sheep fed litter treated with dry heat plus PFA than for those fed Utter treated with dry heat without PFA.

Effect of Ethylene Oxide Fumigation on Amino Acid Composition of Pollen 1

Ethylene oxide fumigation reduced the content of histidine in stored dandelion pollen and of histidine and methionine in rape pollen. Apis mellifera L. colonies reared fewer larvae than control colonies when fed fumigated pollen. Ethylene oxide fumigation also destroyed some unidentified lipid attractants contained in pollen. Foraging bees collected less, and bees in the hive consumed less fumigated pollen than unfumigated pollen.

1866. Yet another effect of ethylene oxide fumigation: Heuser, S. G. & Scudamore, K. A. (1969). Formation of ethylene bromohydrin in flour and wheat during treatment with ethylene oxide. Chemy Ind. no. 31, p. 1054

1866. Yet another effect of ethylene oxide fumigation: Heuser, S. G. & Scudamore, K. A. (1969). Formation of ethylene bromohydrin in flour and wheat during treatment with ethylene oxide. Chemy Ind. no. 31, p. 1054