Estimating the initial absorbed dose of radiation in dried figs using EPR spectroscopy.

Dried figs were studied by Electron Paramagnetic Resonance (EPR) spectroscopy for identification of radiation treatment and dosage assessment. Gamma-irradiated samples show a multicomponent "sugar-like" EPR spectrum with line width of 6-8 mT, centered at g = 2.004. The investigation of the influence of the instrumental parameters microwave power and modulation amplitude on the EPR signal show saturation effect at microwave power above 2 mW and over modulation at modulation amplitude above 0.4 mT. Determination of the stability of radiation induced signals shows, that identification of previous radiation treatment is possible for a long time period after irradiation even more than one year. Dose-response curves of gamma-irradiated samples exhibits a linear response up to about 4 kGy and the saturation of the EPR signal at higher doses. A Single Aliquot Additive dosing method used to estimate the initial absorbed dose in irradiated dried fig flesh shows initial dose 0.25 kGy for the sample irradiated by 5 kGy and 3.7 kGy for those irradiated using 10 kGy. Taking into account the signal decay after 150 days of storage, the dose defined as initial should be 4.65 kGy for the 5 kGy irradiated sample and 8 kGy for that irradiated using 10 kGy.

Headspace Solid-Phase Microextraction/Gas Chromatography-Mass Spectrometry and Chemometric Approach for the Study of Volatile Profile in X-ray Irradiated Surface-Ripened Cheeses.

X-ray irradiation is an emerging non-thermal technology that is used as a preservation and sanitization technique to inactivate pathogens and spoilage organisms, increasing the shelf life of products. In this work, two different types of surface-ripened cheeses, Brie and Camembert, produced with cow milk, were treated with X-rays at three dose levels, 2.0, 4.0 and 6.0 kGy, to evaluate the irradiation effects on the volatile profile using a volatolomic approach. The headspace solid-phase microextraction (HS-SPME) technique combined with gas chromatography-mass spectrometry (GC-MS) was used to extract and analyze the volatile fraction from these dairy matrices. The HS-SPME method was optimized by a central composite design in combination with a desirability optimization methodology. The Carboxen/PDMS fiber, 50 °C for extraction temperature and 60 min for time extraction were found to be the best parameter settings and were applied for this investigation. The obtained fingerprints demonstrated that the irradiation-induced changes are dose dependent. The X-ray irradiation produced many new volatiles not found in the non-irradiated samples, but it also varied the amount of some volatiles already present in the control. Specifically, aldehydes and hydrocarbons increased with the irradiation dose, whereas alcohols, carboxylic acids, esters, methyl esters, ketones, lactones and sulfur-containing compounds showed a non-linear dependence on the dose levels; indeed, they increased up to 4.0 kGy, and then decreased slightly at 6.0 kGy. This trend, more evident in the Camembert profile, is probably due to the fact that these compounds are involved in different oxidation mechanisms of lipids and proteins, which were induced by the radiation treatment. In these oxidative chemical changes, the production and degradation processes of the volatiles are competitive, but at higher doses, the decomposition reactions exceed those of formation. A principal component analysis and partial least square discriminant analysis were used to discriminate between the treated and untreated samples. Moreover, this study allowed for the identification of potential markers of X-ray treatment for the two cheeses, confirming this approach as a useful tool for the control of irradiated surface-ripened cheeses.

Modeling the γ-irradiation inactivation kinetics of foodborne pathogens Escherichia coli O157:H7, Salmonella, Staphylococcus aureus and Bacillus cereus in instant soup.

The objective of the present study was to assess the inactivation kinetics of γ-irradiation of selected foodborne pathogens in instant soup. Escherichia coli O157:H7 (ATCC 25922), Salmonella enterica subsp. enterica serovar Enteritidis (ATCC 13076), Staphylococcus aureus (ATCC 2592), and Bacillus cereus (ATCC 11778) were inoculated into instant soup and irradiated at various doses of 0 (control), 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, and 10.0 kGy using 60Co source. The radiation response of these four major foodborne disease pathogens in instant soup was tested. As expected, the pathogen population decreased with increasing irradiation dose. By comparing bacterial resistance in instant soups according to D10 values, E coli O157: H7 was the most radio-resistant bacteria (D10 of 1.580 kGy), followed by Salmonella (D10 of 1.160 kGy), S aureus (D10 of 0.775 kGy), B cereus (D10 of 0.462 kGy). For modeling of inactivation kinetics, both, the conventional first-order linear model and Weibull model were compared and the goodness of fit of these models was investigated. Weibull model produced a better fit to the data. This research has shown that γ-irradiation was effective to eliminate pathogens in instant soup and it can be a great way to assure the microbiological safety of the instant soup.

Irradiated and radioactively contaminated foods: Analysis of EU RASFF notifications from 1997 to 2022.

Food irradiation technique is an authorized tool used on a commercial scale in many countries to preserve different types of foodstuffs from deterioration caused by microorganisms, insects, and metabolic activity to prolong their shelf life without leaving any residual effect on processed foods, unlike preservatives and pesticides. This study was carried out to analyse the EU Rapid Alert System for Food and Feed (RASFF) notifications on food radiation from 1997 to 2022 in order to identify the most frequently reported products, their origin countries and associated reasons for notification, as well as the most notifying countries, product categories, notification classification, risk decisions, and actions taken. A total of 488 notifications were recorded during this time period. China was the most frequently notified origin country, accounting for 19.88% of all notifications, followed by the United States (11.68%), Russia (7.99%), Vietnam (7.17%), and Poland (5.53%). The top notified product categories were "dietetic foods, food supplements, and fortified foods" (37.09%), followed by fruits and vegetables (23.16%), herbs and spices (8.81%), and prepared dishes and snacks (5.53%). The top 5 notified products were food supplements (25.00%), mushrooms (20.70%), noodles (7.58%), tea (4.51%), and spices (3.69%). The four main reasons for food radiation notifications were unauthorized irradiation (57.58%), too high levels of radioactivity (22.34%), unlabeled irradiation (19.47%), and unauthorized facilities (14.96%). Too many notifications included more than one reason for the notification. Out of 109 notifications related to too-high levels of radioactivity (up to 10755 Bq/kg), 101 were due to the presence of 137Cs, 134Cs, 60Co, and 48Cd in mushrooms, mainly originating from Poland (25), Bulgaria (24), Ukraine (15), and Belarus (12). Such studies provide the necessary data to ensure food safety and encourage countries to implement comprehensive procedures to protect consumers health.

Evaluating Factors Explaining U.S. Consumers' Behavioral Intentions toward Irradiated Ground Beef.

Although food irradiation is deemed safe and endorsed by health-related organizations worldwide, consumers are reluctant to accept the technology. Yet, consumer acceptance is critical as food irradiation has significant potential for increasing the safety and availability of food globally. To communicate about food irradiation, science communicators should understand the psychology behind consumers' decision making related to irradiated foods. Using empirical research, we developed a theoretical model and used structural equation modeling to determine how nine variables affect consumers' behavioral intentions toward irradiated ground beef. We purchased a national quota sample from Qualtrics and surveyed N = 1102 U.S. consumers. The model explained 60.3% of the variance in consumers' attitudes toward food irradiation and 55.4% of their behavioral intentions toward irradiated ground beef. Attitude had the largest positive, total effect on consumers' behavioral intentions, which was followed by subjective social norm and perceived benefit. Perceived risk had the largest negative, total effect on behavioral intentions. Attitude mediated the effect of subjective social norm, perceived benefit, perceived risk, objective knowledge, and food technology neophobia. Environmental concern and health consciousness did not significantly affect behavioral intention. Science communicators should develop messaging strategies that seek to improve consumer acceptance with these factors in mind.

Untargeted Lipidomics and Chemometric Tools for the Characterization and Discrimination of Irradiated Camembert Cheese Analyzed by UHPLC-Q-Orbitrap-MS.

In this work, an investigation using UHPLC-Q-Orbitrap-MS and multivariate statistics was conducted to obtain the lipid fingerprint of Camembert cheese and to explore its correlated variation with respect to X-ray irradiation treatment. A total of 479 lipids, categorized into 16 different lipid subclasses, were measured. Furthermore, the identification of oxidized lipids was carried out to better understand the possible phenomena of lipid oxidation related to this technological process. The results confirm that the lipidomic approach adopted is effective in implementing the knowledge of the effects of X-ray irradiation on food and evaluating its safety aspects. Furthermore, Partial Least Squares-Discriminant Analysis (PLS-DA) and Linear Discriminant Analysis (LDA) were applied showing high discriminating ability with excellent values of accuracy, specificity and sensitivity. Through the PLS-DA and LDA models, it was possible to select 40 and 24 lipids, respectively, including 3 ceramides (Cer), 1 hexosyl ceramide (HexCer), 1 lysophosphatidylcholine (LPC), 1 lysophosphatidylethanolamine (LPE), 3 phosphatidic acids (PA), 4 phosphatidylcholines (PC), 10 phosphatidylethanolamines (PE), 5 phosphatidylinositols (PI), 2 phosphatidylserines (PS), 3 diacylglycerols (DG) and 9 oxidized triacylglycerols (OxTG) as potential markers of treatment useful in food safety control plans.

Volatolomic approach by HS-SPME/GC-MS and chemometric evaluations for the discrimination of X-ray irradiated mozzarella cheese.

In this work, an untargeted screening of the volatile profile of X-ray irradiated mozzarella cheese was carried out to study the possible radio-induced modifications. A Central Composite Design (CCD) for Response Surface Methodology (RSM) was employed to optimise the HS-SPME analysis of volatile organic compounds (VOCs). The optimised HS-SPME conditions, in terms of sample amount (5.0 g), extraction temperature (50 °C) and extraction time (75 min), were used to analyse non-irradiated and irradiated samples at three dose levels, 1.0, 2.0, 3.0 kGy. Partial Least Squares-Discriminant Analysis (PLS-DA) and Linear Discriminant Analysis (LDA) were applied to explore the variation of volatile profile with respect to the X-ray irradiation treatment. Both methods highlighted a high discriminant capability with excellent values of accuracy, specificity and sensitivity, demonstrating the effectiveness of the volatolomic approach to evaluate the variations induced by the treatment and allowing to select a total of 35 VOCs as potential irradiation markers.

Detection, Identification, and Inactivation of Histamine-forming Bacteria in Seafood: A Mini-review.

Seafood is one of the essential sources of nutrients for the human diet. However, they can be subject to contamination and can cause foodborne illnesses, including scombroid fish poisoning caused by histamine. Many microorganisms can produce enzymes that eventually decompose endogenous histidine to histamine in postmortem fish muscles and tissues. One of these is histamine-forming bacteria (HFB), primarily found in the gills, gut, and skin of fishes. Previous studies linked a plethora of Gram-negative HFB including Morganella spp. and Photobacterium spp. to scombroid fish poisoning from many types of seafood, especially the Scombridae family. These bacteria possess the hdc gene to produce histidine decarboxylase enzyme. It was reported that Gram-negative HFB produced 6345 ppm in tuna and 1223 ppm in Spanish mackerel. Interestingly, Gram-positive HFB have been isolated in the seafood samples with lower histamine levels. It suggests that Gram-negative HFB are the major contributor to the accumulation of histamine in seafood. Several analytical methods are available to detect and identify HFB and their histamine metabolites from seafood substrates. Rapid test kits can be used in food production settings for early detection of histamine to avoid food intoxication. Furthermore, high hydrostatic pressure and irradiation treatment could prevent the proliferation of HFB and inactivate the existing histidine decarboxylase (HDC) activity. As demonstrated in different seafood model systems, the HDC activity was deactivated at a maximum high hydrostatic pressure level of 400 MPa. The complete inactivation of HFB was achieved by gamma irradiation at a dose of 4.0 kGy. Other postharvest treatments, like enzymatic degradation and electrolyzed oxidizing water, were studied as sustainable methods for bacterial growth prevention and enzyme inactivation. However, other HFB react differently to these treatment conditions, and further studies are recommended.

Estimation of doses absorbed by potato tubers under electron beam or X-ray irradiation using an optical fingerprinting strategy.

High-energy electron beam and X-ray processing of foods can be used for extending their storage life and for combating pests and pathogens. Several instrumental techniques are used to estimate irradiation doses in foods, but these methods are complex and laborious, require expensive equipment, and do not always allow to determine low doses. This study was aimed at developing simple methods for detecting irradiation in potato tubers and for dose estimation. We used a "fingerprinting" strategy that does not involve quantitation of any compound; instead, the rate of indicator reactions involving carbocyanine dyes is measured. The dye content was monitored by its near-infrared fluorescence intensity and visible-light absorption. Potatoes not subjected to treatment and those irradiated with different doses (10, 100, 1000, 5000, or 10,000 Gray) could be distinguished by linear discriminant analysis. Thus, the order of magnitude of the absorbed dose can be estimated with 89% ± 3% accuracy for a mixture of tubers of two potato varieties irradiated with an electron beam or with 95% ± 8% accuracy for one variety irradiated with an X-ray source.

[Detection of Gamma-Ray Irradiation History of Dried Plant-Based Foods via the Analysis of 5,6-Dihydrothymidine].

Irradiation is widely used worldwide to sterilize and kill insects in food, and prevent the germination of agricultural products. However, in Japan, food irradiation is prohibited except to prevent potato sprouting. Herein, 5,6-dihydrothymidine (DHdThd) residue-a damaged nucleoside generated from the thymidine (dThd) residue in DNA contained in food upon irradiation-was used as a detection indicator. Eight dried plant-based food samples were gamma ray-irradiated in the range from 3.2 to 8.3 kGy. Subsequently, DNA was extracted from the irradiated sample and digested into nucleosides by the three enzymes, and the test solution was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Evidently, in all samples, the concentration ratio of DHdThd to dThd in the test solution (DHdThd/dThd) was dependent on the irradiation dose; moreover, during storage under frozen conditions for at least 890 d post-irradiation, this concentration ratio was equal to that immediately after irradiation. The irradiation histories of the eight types of dried plant-based food samples were correctly detected.

Irradiation impact on biological activities of Anthraquinone pigment produced from Talaromyces purpureogenus and its evaluation, characterization and application in beef burger as natural preservative.

BACKGROUND: The demand for natural coloring and preservative agents in food industry is increasing day by day as a result of awareness of the negative health effects of synthetic color preservatives. Consumers want foods with less processing, a longer shelf life, and clear labels that list only natural ingredients and food additives with familiar names that promote good health. In order to meet consumer demands and regain consumers' confidence in the safety of food products, the food industry was compelled to search for natural alternatives with strong antibacterial and antioxidant properties. Therefore, the objective of this study was to produce a microbial pigment that not only serve as food coloring agents but also provide health advantages owing to their bioactivities. Additionally, the potential use of anthraquinone pigment (AQP) as a natural food preservative compared to gamma irradiation was also examined to extend the shelf life of the beef burger and improve its hygienic quality. RESULTS: This study used Talaromyces purpureogenus AUMC2603 to produce the red natural pigment, which was identified as an anthraquinone pigment (AQP). According to the results, gamma (γ) radiation had no significant effect on AQP's antibacterial properties. However, it has a negative, considerable effect on antioxidant activity, where a large dose of γ-ray may change the antioxidant components and lessen the AQP's capacity to scavenge free radicals. Additionally, the γ ray-treated AQP had a strong cytotoxic activity in relation to a high γ-ray dose. As a result, it is suggested that AQP-containing foods should not be irradiated. The extracted AQP was applied as a food additive to improve the quality and increase the shelf life of beef burgers. Significant antibacterial and antioxidant action has been shown at 2% (w/v) AQP. The findings demonstrated that the treatment of beef burger with AQP decreased the initial total bacterial count and psychrophilic bacteria and extended the shelf-life of beef burger in comparison to the control (beef burger with no addition of AQP, butylated hydroxytoluene (BHT) or gamma radiation treatment). On the other hand, there was no substantial difference in the overall amount of mold and yeast or coliform at zero time. According to sensory characteristics, beef burgers had a shelf life of 6 days for controls and 9, 12, and 15 days for AQP-treated samples at 0.5, 1 and 2%, respectively, compared to γ- irradiated samples, 9 and 21 days, at 3 and 5 Kilo Gray (KGy), respectively. CONCLUSIONS: This research provides a natural red pigment from Talaromyces purpureogenus with potent biological activities as antimicrobials and antioxidants to be applied as coloring, additive, and preservative agent in the food industry. Also, the tested pigment offers a powerful alternative to gamma irradiation for extending the shelf life of food products.

Impact of irradiation on physico-chemical and nutritional properties of fruits and vegetables: A mini review.

Background: Fruits and vegetables are healthy because they contain good nutrients and secondary metabolites that keep the body healthy and disease-free. Post-harvest losses of fresh fruits and vegetables limit access and availability as a result of foodborne infections and poor storage technologies. The selection of fruits and vegetables depend on the starting microbial load, the size of fruits and vegetables, and the type of infrastructure. Scope and approach: Despite the positive impacts of conventional thermal (roasting, boiling, blanching) and some non-thermal processing techniques such as High Pressure Processing (HPP), Pulse Electric Field (PEF), Cold Plasma Technology (CPT) on shelf-life extension, their use is commonly associated with a number of negative consequences on product quality such as cold plasma treatment increases the acidity and rate of lipid oxidation and further decrease the colour intensity and firmness of products. Similarly, in high pressure processing and pulse electric field there is no spore inactivation and they further limit their application to semi-moist and liquid foods. On that account, food irradiation, a non-thermal technique, is currently being used for post-harvest preservation, which could be very useful in retaining the keeping quality of various fresh and dehydrated products without negatively affecting their versatility and physico-chemical, nutritional and sensory properties. Conclusion: Existing studies have communicated the effective influence of irradiation technology on nutritional, sensory, and physico-chemical properties of multiple fruits and vegetables accompanying consequential deduction in microbial load throughout the storage period. Food irradiation can be recognized as a prevalent, safe and promising technology however, still is not fully exploited on a magnified scale. The consumer acceptance of processed products has always been a significant challenge for innovative food processing technologies such as food irradiation. Therefore, owing to current review, additional scientific evidences and efforts are still demanded for increasing its technological request.

Evaluation of Photon Interaction Parameters of Some Antioxidants for Food Irradiation Applications.

This study aimed to investigate the interaction parameters of antioxidant molecules in some spices and vegetables with gamma radiation. At first, mass attenuation coefficients (MACs, cm2/g) of gingerol, rosmarinic acid, quercetin, curcumin, eugenol, piperine, allicin, and capsaicin molecules were determined at the photon energies (13-1332 keV) emitted from the radioactive isotopes Am-241, Ba-133, Co-60, and Cs-137 with the help of the EpiXS and WinXCOM programs. The smallest and largest MAC values were found as 1.20 and 8.48 cm2/g at 13 keV and 0.059 and 0.058 cm2/g at 1332 keV for eugenol and allicin, respectively. It was observed that both results support each other. Using the MAC values, the effective atomic number and electron density (Zeff and Neff) values of the molecules were derived. The Zeff values for gingerol and allicin were obtained in the range of 5.79-3.40 and 13.85-4.53, respectively. The variation of the buildup factors of antioxidants in the range of 0.015-15 MeV depending on the chemical composition and penetration depth were also examined. It was noticed that the photon accumulation was the lowest in allicin and the highest in gingerol and eugenol. The results obtained from this study will make an essential contribution to dose calculations in food irradiation studies.

Extraction and analysis of an organophosphate salt nucleating agent from irradiated polypropylene resin.

Although it is well-established that irradiation of produce can reduce food-borne pathogens and spoilage organisms, data on the effect of irradiation on polymer additives in food packaging materials are limited, particularly for those additives used in packaging leafy greens or in current food packaging materials. We investigated the effects of irradiating a nucleating agent, aluminium, hydroxybis[2,4,8,10-tetrakis(1,1-dimethylethyl)-6-hydroxy-12H-dibenzo [d,g][1,3,2]dioxaphosphocin 6-oxidato]- (CAS Reg. No. 151841-65-5), at doses of 1-20 kGy in polypropylene. That nucleating agent was then extracted using accelerated solvent extraction and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), liquid chromatography-photodiode array detection (LC-PDA), and solid-state nuclear magnetic resonance (SSNMR) spectroscopy. We found this nucleating agent was not significantly affected by radiation treatment up to 20 kGy. Therefore, this nucleating agent could potentially be useful in food packaging materials that will be irradiated at doses of 20 kGy or less. Establishing which additives are stable under anticipated irradiation doses will help support safety evaluation of food packaging materials.

The attitude of Polish consumers toward food irradiation as one of the methods of food preservation.

Background: Food irradiation is one of the methods of food preservation. Unfortunately, despite many opinions from national and international organizations that confirm the safety of the irradiation technique, the irradiated food market is slowly developing, which is particularly noticeable in European countries, including Poland. Objectives: The main objective of this study was to determine the attitude of Polish consumers toward irradiated food and to find out whether familiarizing the respondents with educational materials on the irradiation technique would change their attitudes. Material and methods: In response to the objective of the study, an online survey (with the presentation of educational materials) was conducted with 609 respondents living in the Silesian Voivodeship, Poland. A specially prepared author's questionnaire was used, containing questions relating to: sociodemographic data, food preservation, food irradiation. An integral part of the survey was a multimedia presentation containing information about the food irradiation process. Results: A low level of knowledge about food irradiation was found--90.31% (n = 550) of the respondents had never heard of this method of preservation before. The percentage of respondents with a positive attitude toward radiation-preserved products increased significantly after providing informative material, from 6.20 (n = 38) to 67.16% (n = 409). The final attitude of the respondents toward irradiated food varied and depended on age, education and place of residence-positive attitudes toward irradiation predominated among those who were young (<30 years old), had a higher education and lived in cities >100,000 inhabitants. Educational materials also had a significant impact on consumers' interest in purchasing irradiated food-the percentage of people declaring a willingness to purchase this type of product increased from 19.20 (n = 117) to 59.30% (n = 361). Almost 60% of the respondents were willing to purchase irradiated foods. Women, on average, were more likely to be interested in purchasing irradiated food compared to men. Conclusions: The survey indicates that irradiated food could be commercially introduced in Poland, but on the condition that an effective educational program is planned.

Food irradiation: a promising technology to produce hypoallergenic food with high quality.

The increasing incidence of food allergy cases is a public health problem of global concern. Producing hypoallergenic foods with high quality, low cost, and eco-friendly is a new trend for the food industry in the coming decades. Food irradiation, a non-thermal food processing technology, is a powerful tool to reduce the allergenicity with the above advantages. This review presents a summary of recent studies about food irradiation to reduce the allergenicity of food, including shellfish, soy, peanut, milk, tree nut, egg, wheat and fish. Principles of food irradiation, including mechanisms of allergenicity-reduction, irradiation types and characteristics, are discussed. Specific effects of food irradiation are also evaluated, involving microbial decontamination, improvement or preservation of nutritional value, harmful substances reduction of food products. Furthermore, the advantages, disadvantages and limitations of food irradiation are analyzed. It is concluded that food irradiation is a safety tool to reduce the allergenicity of food effectively, with high nutritional value and long shelf-life, making it a competitive alternative technology to traditional techniques such as heating treatments. Of note, a combination of irradiation with additional processing may be a trend for food irradiation.

Protective rules of natural antioxidants against gamma-induced damage-A review.

Phytochemicals accessible in food have demonstrated efficiency against impairment by gamma radiation. The review presented here is an attempt to show the pharmacological outline of the activity of the natural antioxidants and its primary action of molecular mechanism against the damage induced by gamma rays. This research focused on the results of the in vitro dosage of natural antioxidants relationship, and on the correlation of this information with the statistical variables. Moreover, it deliberated the natural compounds which could decrease the unwelcome impacts of gamma radiation and safeguard biological systems from radiation-stimulated genotoxicity. The outcomes indicated that natural compounds can be utilized as an adjunct to orthodox radiotherapy and cultivate it as an effectual drug for the clinical administration of ailments.

Combined effects of irradiation and storage time on the nutritional and chemical parameters of dried Agaricus bisporus Portobello mushroom flour.

Portobello variety of Agaricus bisporus mushrooms, appreciated for its taste, makes it desirable to be eaten fresh and also as flour in soups and gravies. Gamma and electron-beam radiation at four doses (1, 2, 5, and 10 kGy) were used to analyze its preservation effect on Portobello mushroom flour. A proximate analysis, as well as the impact on fatty acids, tocopherols, soluble sugars, organic acids, and ergosterol profiles, were performed every 3 months, during a storage period of 1 year. Gamma rays preserved mannitol (most abundant soluble sugar) over the 12 months, while electron beam radiation preserved organic acids. No significant changes were sought for any radiation type, and the slight changes extracted from the estimated marginal means reveal a tendency for irradiation as having preserving effects of nutrients and other important molecules. Thus, both irradiation types, up to 10 kGy are suitable for preservation of A. bisporus Portobello flour.

A New Fluorometric Dosimetry for Low-medium Gamma Radiation Doses.

In this study, for the first-time, solutions of a Schiff base was evaluated as a possible chemical dosimeter for gamma-rays at low-medium dose ranges. The solutions of N-N'-bis(salicylidene)-1,3-propanediamine (LH2) were prepared at different ethanol/water compositions and the effect of various irradiation doses on the fluorometric response of these solutions were investigated. Fluorescence spectra of non-irradiated and irradiated solutions showed that fluorescence intensity of LH2 (λex = 375 nm, λem = 498 nm) decreased as the radiation dose increased. This decrease was observed over a wider dose range for the solutions that contain 40-60 % water. In order to increase the sensitivity of the method, LH2-Zn complexes were formed by adding Zn (II) to non-irradiated and irradiated LH2 solutions. After that, analytical parameters such as linearity, LOD, LOQ, repeatability and reproducibility were determined by measuring fluorescence spectra of these solutions (λex = 350 nm, λem = 444 nm). The performance characteristics of the chemical dosimetry system suggest that LH2 can be used as a dosimeter in dose range 0.04-5 kGy. The proposed method is simple, sensitive, reproducible and cost-effective, and can be useful in measuring doses in food irradiation.

Assessment of contamination of Salmonella spp. in imported black pepper and sesame seed and salmonella inactivation by gamma irradiation.

This study shows the frequency of seeds samples contaminated by Salmonella spp. collected randomly from local markets; on 30 black pepper sample no contaminated sample was found while Salmonella spp. was detected in 3 of 36 (8.3%) analyzed sesame samples; three different serotypes were identified: S. Montevideo, S. Stanleyville e S. Tilene. The efficacy of gamma irradiation to inactivate Salmonella Montevideo in black pepper and sesame irradiated between 1 and 5 kGy was evaluated. 3 kGy is sufficient to reduce of 3-4 log CFU/g; whereas 5 kGy have been need to reduce 5.5-6 log CFU/g for samples of black pepper and sesame. No statistically significant differences were found between black pepper and sesame.