Worldwide Status of Fresh Fruits Irradiation and Concerns about Quality, Safety, and Consumer Acceptance.

Development of knowledge-based food preservation techniques have been a major focus of researchers in providing safe and nutritious food. Food irradiation is one of the most thoroughly investigated food preservation techniques, which has been shown to be effective and safe through extensive research. This process involves exposing food to ionizing radiations in order to destroy microorganisms or insects that might be present on and/or in the food. In addition, the effects of irradiation on the enzymatic activity and improvement of functional properties in food have also been well established. In the present review, the potential of food irradiation technology to address major problems, such as short shelf life, high-initial microbial loads, insect pest management (quarantine treatment) in supply chain, and safe consumption of fresh fruits was described. With improved hygienic quality, other uses, such as delayed ripening and enhanced physical appearance by irradiation were also discussed. Available data showed that the irradiation of fruits at the optimum dose can be a safe and cost-effective method, resulting in enhanced shelf life and hygienic quality with the least amount of compromise on the various nutritional attributes, whereas the consumer acceptance of irradiated fruits is a matter of providing the proper scientific information.

Alcoholic extraction enables EPR analysis to characterize radiation-induced cellulosic signals in spices.

Different spices such as turmeric, oregano, and cinnamon were γ-irradiated at 1 and 10 kGy. The electron paramagnetic resonance (EPR) spectra of the nonirradiated samples were characterized by a single central signal (g = 2.006), the intensity of which was significantly enhanced upon irradiation. The EPR spectra of the irradiated spice samples were characterized by an additional triplet signal at g = 2.006 with a hyperfine coupling constant of 3 mT, associated with the cellulose radical. EPR analysis on various sample pretreatments in the irradiated spice samples demonstrated that the spectral features of the cellulose radical varied on the basis of the pretreatment protocol. Alcoholic extraction pretreatment produced considerable improvements of the EPR signals of the irradiated spice samples relative to the conventional oven and freeze-drying techniques. The alcoholic extraction process is therefore proposed as the most suitable sample pretreatment for unambiguous detection of irradiated spices by EPR spectroscopy.

An improved approach to identify irradiated spices using electronic nose, FTIR, and EPR spectroscopy.

Changes in cumin and chili powder from India resulting from electron-beam irradiation were investigated using 3 analytical methods: electronic nose (E-nose), Fourier transform infrared (FTIR) spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy. The spices had been exposed to 6 to 14 kGy doses recommended for microbial decontamination. E-nose measured a clear difference in flavor patterns of the irradiated spices in comparison with the nonirradiated samples. Principal component analysis further showed a dose-dependent variation. FTIR spectra of the samples showed strong absorption bands at 3425, 3007 to 2854, and 1746 cm(-1). However, both nonirradiated and irradiated spice samples had comparable patterns without any noteworthy changes in functional groups. EPR spectroscopy of the irradiated samples showed a radiation-specific triplet signal at g = 2.006 with a hyper-fine coupling constant of 3 mT confirming the results obtained with the E-nose technique. Thus, E-nose was found to be a potential tool to identify irradiated spices.

Physical-, chemical-, and microbiological-based identification of electron beam- and γ-irradiated frozen crushed garlic.

Identification of frozen crushed garlic, commercially available in the Korean market, was performed using four different analytical techniques (three screening and one confirmation). The garlic samples produced in Korea and China were irradiated (electron-beam and γ-rays) at 0, 1, 4, and 7 kGy. Non-irradiated samples showed a relatively moderate population of aerobic bacteria and yeasts/molds around 10(5) CFU/g. Irradiation treatments unequivocally reduced the microbial/fungal populations with dose increments. Microbiological screening through direct epifluorescent filter technique/aerobic plate count (DEFT/APC) method effectively differentiated the non-irradiated and irradiated samples. An electronic nose method positively differentiated the odor patterns of samples based on chemical sensing. However, photostimulated luminescence technique (PSL) exhibited poor sensitivity. Minerals separated from irradiated samples produced thermoluminescence (TL) glow curves in the specific temperature range of 150-250 °C. In conclusion, TL confirmatory analysis gave the most promising results in detecting the irradiation status of garlic samples irrespective of the production origin and type of ionizing radiation treatment.

Chemical and sensory quality of fresh pomegranate fruits exposed to gamma radiation as quarantine treatment.

The U.S. Department of Agriculture in February 2012 approved the import of fresh pomegranates subjected to irradiation as a quarantine procedure with a minimum absorbed dose of 0.4kGy against different pests. This study evaluated the application of different gamma-irradiation doses (0.4, 1, and 2kGy) in fresh pomegranate fruits and their effect on the chemical and sensory characteristics. The total soluble solids, titratable acidity, and pH values remained unaffected up to 1kGy treatment. Irradiation caused a significant decrease in the total anthocyanins and phenolic content. A strong positive correlation was observed among the antioxidant activities, total phenolics and anthocyanin contents. In general, a stronger preference was shown by sensory panelists for the juice from irradiated fruits. This study provides research-based information about the application of irradiation as a quarantine disinfestation treatment to enhance the marketing and consumer acceptance of pomegranates.

Luminescence properties and compositions of contaminating inorganic minerals separated from gamma-irradiated fresh and white ginsengs from different areas.

Gamma-irradiation (0-7 kGy) of ginseng is permitted in Korea for the purpose of microbial decontamination; with strict labeling, traceability and monitoring requirements. An identification study was conducted to determine the photostimulated-luminescence (PSL) and thermoluminescence (TL) properties of gamma-irradiated fresh and white ginsengs cultivated in different areas. Dosedependent PSL-based screening was possible for white ginseng samples; however, inappropriate results from non-irradiated fresh ginseng samples were obtained, showing intermediate (700 to 5,000) or positive (T2 >5,000, irradiated) PSL counts due to the abundance of minerals on the surfaces of the samples. TL analysis of separated minerals from all non-irradiated samples gave TL glow curves of low intensity with a maximum peak after 300℃. However, well-defined irradiation-specific (high intensity with a maximum peak at about 200℃) glow curves were observed for all the irradiated samples, regardless of their type and origins. TL ratios (first glow curve /second glow curve) were also determined to confirm the irradiated (>0.1) and non-irradiated (<0.1) results. SEM-EDX (scanning electron microscope-energy dispersive X-ray) and XRD (X-ray diffraction) spectroscopic analyses showed that feldspar and quartz minerals were the main source for the typical radiation-specific luminescence properties.

Two Cases of Vitiligo Developed on the Persisting Dermal Melanocytosis: Is There a Difference between Epidermal Melanocytes and Dermal Melanocytes?

Vitiligo is one of the most common pigmentary skin disorders; it is characterized by circumscribed depigmented macules due to the destruction of melanocytes. Although the etiology of vitiligo has not been fully elucidated, multiple factors including autoimmune and oxidative stress have been implicated in the pathogenesis of vitiligo. In contrast, dermal melanocytosis is histologically characterized by the presence of dermal melanocytes. It has been described that there are ectopic dermal melanocytes, which have failed to reach their proper location. A literature search revealed very few reports of patients with vitiligo developing vitiligo within dermal melanocytosis. Here, we report two cases of patients with vitiligo that occurred at pre-existing sites of dermal pigmented lesions. The histopathology showed the loss of epidermal melanocytes in spite of the existence of melanocytes in the dermis. There was no significant infiltration of inflammatory cells in the dermis. These cases illustrate unknown environmental factors as well as heterogeneity.

Investigation of radiation-induced free radicals and luminescence properties in fresh pomegranate fruits.

Radiation-induced free radicals and luminescence properties were investigated in γ-irradiated (0-3 kGy) pomegranate ( Punica granatum L.) fruits. Photostimulated luminescence (PSL) analysis showed limited applicability, and only 3 kGy-irradiated pomegranates showed positive PSL values (>5000 PCs). Thermoluminescence (TL) glow curve features, such as intensity and the presence of maximum glow peak in radiation-specific temperature range (150-250 °C), provided definite proof of irradiation, and the TL ratios (TL1/TL2) also confirmed the reliability of TL results. Scanning electron microscopy energy dispersive X-ray (SEM-EDX) analysis of the separated minerals showed that feldspar and quartz minerals were responsible for the luminescence properties. Radiation-induced cellulose radicals were detected in the seeds and rinds by ESR analysis. The ESR results were better in freeze-dried samples than in alcohol-extracted ones. A positive correlation was found between the ESR and TL signal intensities and irradiation doses; however, the most promising detection of the irradiation status was possible through TL analysis.

Characterization of radiation-induced luminescence properties and free radicals for the identification of different gamma-irradiated teas.

Two kinds (20 each) of gamma-irradiated (0, 5, and 10 kGy) tea samples, blended powders and packed in sachets (tea bags), were investigated using photostimulated luminescence (PSL), thermoluminescence (TL), and electron spin resonance spectroscopy (ESR) to identify their irradiation status. PSL-based rapid screening was possible for all the control samples except for one packed and two powdered samples. The irradiated samples presented a good dose-dependent PSL count except two powdered samples with very low PSL sensitivity. TL analysis provided the most reliable results, in which all the irradiated samples were identified using a well-defined high-intensity TL glow curve in a temperature range of 150-250 °C. The TL results were also confirmed by determining the TL ratio (TL1/TL2), which was <0.1 in all the non-irradiated samples and >0.1 in the irradiated ones. ESR spectroscopy was effective for only 3 packed and 6 powdered samples showing the radiation-induced cellulosic and sugar radical signals, respectively.

Characterization and identification of gamma-irradiated sauces by electron spin resonance spectroscopy using different sample pretreatments.

Tomato ketchup, barbeque sauce, sweet chili sauce, and spaghetti sauce were gamma irradiated at 0, 1, 5, and 10 kGy. Electron spin resonance (ESR) technique was used to characterize the irradiated sauces, targeting radiation-induced cellulose radicals and using a modified sample pretreatment method. The samples were first washed with water, and then the residues were extracted with alcohol. The non-irradiated sauces exhibited the single central signal, whose intensity showed a significant increase on irradiation. The ESR spectra from the radiation-induced cellulose radicals, with two side peaks (g=2.02012 and g=1.98516) equally spaced (± 3 mT) from the central signal, were also observed in the irradiated sauces. The improvements in the central (natural) and radiation-induced (two side peaks corresponding to the cellulose radicals) signal intensities were obvious, when compared with routine freeze-drying and alcoholic-extraction techniques.

Absorbed-dose estimation and quality attributes of gamma-irradiated fresh shiitake mushrooms.

BACKGROUND: The general use of food irradiation requires reliable identification methods as well as extensive quality characterization. Shiitake (Lentinus edodes) mushrooms, packed in polystyrene trays and covered with polyvinylchloride film, were investigated for dose-dependent identification and quality characterization upon gamma irradiation (0, 1, 2, and 3 kGy). RESULTS: Thermoluminescence (TL) analysis of separated minerals provided excellent results to characterize the irradiated mushrooms. Low-dose re-irradiation (200-600 Gy), medium-dose re-irradiation (1-3 kGy) and high-dose re-irradiation (2-6 kGy) were performed and compared using an additive dose method. An electronic-nose analysis showed a difference in the volatile profiles of mushrooms following irradiation. One-kGy-irradiated mushrooms showed similar or better quality attributes to those of the control samples. Scanning electron microscopy revealed the dose-dependent degradation in microstructure of mushrooms upon irradiation. CONCLUSION: An absorbed dosed estimation was possible using TL analysis in which 1-3 kGy re-irradiation technique gave most promising results. An E-nose analysis effectively distinguished the samples based on irradiation history. The best quality attributes were observed at 1 kGy irradiation. However, the drastic effects of irradiation were prominent in 2 and 3 kGy-irradiated mushrooms.

Identification and characterization of gamma-irradiated dried Lentinus edodes using ESR, SEM, and FTIR analyses.

UNLABELLED: A detailed electron spin resonance (ESR) analysis for different parts of gamma-irradiated (0 to 50 kGy) dried mushroom (Lentinus edodes) was conducted to identify radiation-induced signals. All studied mushroom parts except gills produced strong dose-dependent radiation-induced ESR signals particularly at about g = 2.0076, 20005, and 1.9911 demonstrating the generation of crystalline sugar radicals following irradiation. The intensity of these signals was highest in cap skin samples, followed by the cap core, stem skin, whole mushroom powder, and stem core samples, respectively. ESR-based identification was easily possible at 2 kGy or more using mushroom cap skin or cap core as samples. The radiation-induced ESR signals were found sensitive to thermal treatment showing the limitation of ESR-based detection in case of heat-processed samples. Scanning electron microscopy (SEM) showed micro-structural damage upon irradiation resulting decreased percentage of rehydration; however, no major alteration was observed through the Fourier transform infrared (FTIR) spectra. Irradiation changed the structural morphology; however, the main functional groups were stable against radiation treatment. PRACTICAL APPLICATION: Food irradiation can confirm hygienic quality and prolong the product shelf life. However, due to lack of international consensus, effective identification methods and detailed quality characterization are required for the general use of this technology.

Identification of a gamma-irradiated ingredient (garlic powder) in Korean barbeque sauce by thermoluminescence analysis.

UNLABELLED: Thermoluminescence (TL) analysis was applied to identify gamma-irradiated garlic powder in Korean barbeque sauce before and after pasteurization (85 °C, 30 min), when blended in different ratios (1%, 3%, and 5%). The sauce sample with nonirradiated garlic powder gave a background glow curve. However, the sample blended with irradiated ingredient (1 and 10 kGy) showed typical TL glow curves at temperatures of 150 to 200 °C. The identification properties of sauce samples were more influenced by blending ratios than by irradiation doses, showing that 3% and 5% added samples produced glow curves at 150 to 250 °C. After pasteurization of the samples containing the irradiated ingredient, TL glow intensity decreased but did not change its shape or temperature range. As a result, the pasteurization of Barbeque sauces containing irradiated ingredients had reduced TL glow intensity, but the shape and temperature range of glow curve were still able to provide information required for confirming irradiation treatment. PRACTICAL APPLICATION: To monitor the irradiated food in international market, thermoluminescence (TL) analysis is considered most promising identification technique because of its sensitivity and long-term stability. In this study the applicability of TL analysis to detect an irradiated ingredient (garlic powder) added in low quantity to a food matrix (sauce) was investigated. The effect of processing (pasteurization) on TL results was also evaluated.

Investigation of Different Factors Affecting the Electron Spin Resomance-based Characterization of Gamma-irradiated Fresh, White, and Red Ginseng.

Fresh (raw roots), white (dried), and red (steamed-drid) ginseng samples were gamma-irradiated at 0 to 7 kGy. Electron spin resonance (ESR) technique was used to characterize the irradiation status of the samples, targeting the radiation-induced cellulose radicals after different sample pretreatments. All non-irradiated samples exhibited a single central signal (g=2.006), whose intensity showed significant increase upon irradiation. The ESR spectra from the radiation-induced cellulose radicals, with two side peaks (g=2.0201 and g=1.9851) equally spaced (±3 mT) from the central signal, were also observed in the irradiated samples. The core sample analyzed after alcoholic-extraction produced the best results for irradiated fresh ginseng samples. In the case of irradiated white and red ginseng samples, the central (natural) and radiation-induced (two-side peaks corresponding to cellulose radical) signal intensities showed little improvement on alcoholic-extraction. The water-washing step minimized the effect of Mn(2+), but reduced the intensity of side peaks making them difficult to indentify. The effect of different origins was negligible, however harvesting year showed a clear effect on radiation-induced ESR signals.

Case of isolated benign primary cutaneous plasmacytosis in a child.

A collection of plasma cells in the skin can represent a broad spectrum of disease entities. Secondary syphilis, primary cutaneous plasmacytoma, primary cutaneous plasmacytosis, cutaneous lymphoid hyperplasia and nodular amyloidosis are considered possible differential diagnoses. We present a case of a 7-year-old girl with an erythematous scaly plaque on her right buttock that had been present for approximately 5 years. Prior to her visit to our department she had been treated at a local dermatology clinic with topical methylprednisolone acetate and topical calcitriol without significant improvement. Histopathological examination revealed psoriasiform hyperplasia, hyperkeratosis, parakeratosis and a band-like or dense perivascular infiltration of plasma cells with a few lymphocytes and histiocytes. Other laboratory tests were within the reference ranges. At our department, the patient was given oral prednisolone along with an intralesional injection of triamcinolone and application of topical methylprednisolone acetate and tacrolimus hydrate to the affected area. The lesion improved significantly but recurred 3 months later. We present a rare case of isolated benign primary cutaneous plasmacytosis in a female pre-adolescent child.

Investigation of hair shaft in seborrheic dermatitis using atomic force microscopy.

BACKGROUND/PURPOSE: We have investigated the changes of seborrheic dermatitis (SD) on the hair shaft in the morphological and physical properties using atomic force microscopy (AFM). METHODS: Hair samples were obtained from the lesional and perilesional regions in 15 patients with SD. Fifteen healthy adults were included as the control group. From the topography of hair obtained by AFM, the height of the scale, step height, roughness, diameter, and pit were determined. RESULTS: The scale thickness of the SD-affected hair was sevenfold more than in the control hair showing statistically significance. The lesional hair showed greater roughness parameters of Sa, Sq, and Sz than the perilesional and the control hair, but this difference was not significant. The cuticle of the lesional hair was significantly damaged while perilesional hair showed a very distinct cuticle structure with smooth edges and a regular interval between the cuticles. The diameter of the lesional hair was significantly lesser by 10-35% than that of the perilesional hair. The pit was rarely observed in the SD-affected hair collected from both the lesional and perilesional regions. CONCLUSION: The changes in the hair shaft affected SD was measured using AFM non-invasively. AFM could be a useful tool in monitoring the treatment response and the severity of SD.

Fusarium solani onychomycosis of the thumbnail coinfected with Pseudomonas aeruginosa: report of two cases.

Fusarium species are non-dermatophytic moulds, which are commonly known soil saprophytes and important plant pathogens, and have been frequently reported to be aetiological agents of opportunistic infections in humans. The prevalence of onychomycosis caused by Fusarium species varies in the literature because of geographical differences in mould distribution and diagnostic methods. Onychomycosis caused by Fusarium species is considered rare in Korea, and only four cases have been described to date. Pseudomonas aeruginosa also can infect nails and cause green nail syndrome, and recent research has shown that fungal infection may potentiate the colonisation or growth of P. aeruginosa within a nail. Furthermore, such coinfection with P. aeruginosa can prevent the isolation of the fungus because of bacterial overgrowth in culture. The authors report the cases of two immunocompetent patients with F. solani onychomycosis coinfected with P. aeruginosa. Both presented with a greenish/yellowish discolouration and thickening of a thumbnail, and were treated with systemic ciprofloxacin in combination with itraconazole or terbinafine.

Luminescence characteristics for identifying irradiated black soybeans.

PURPOSE: Considering the commercial use of food irradiation and the prevalence of international trade of irradiated food and agricultural commodities, black soybeans originating from China or Korea were irradiated at 0-5 kGy. Photostimulated luminescence (PSL) and thermoluminescence (TL) were investigated for their ability to identify characteristics that would distinguish irradiated from non-irradiated samples. MATERIALS AND METHODS: Dried black soybeans [Glycine max (L.) Merr.] were irradiated using a Co-60 gamma irradiator or an electron-beam accelerator and then analysed by PSL and TL. RESULTS: PSL photon counts were higher in irradiated samples than in non-irradiated ones and increased with applied doses, making it possible to distinguish irradiated from non-irradiated samples. The TL analysis revealed glow curves (TL1) with low intensity for non-irradiated samples but a higher intensity (approximately 200°C) for irradiated samples, showing increased intensities with radiation dose. The minerals were re-irradiated at 1 kGy and the second TL glow curve (TL2) was measured. Based on the calculated TL ratios (TL1/TL2) and the shape of TL1 glow curves, the irradiated samples could be distinguished from non-irradiated ones. CONCLUSIONS: PSL and TL are effective screening and reference methods for distinguishing gamma ray or electron beam irradiated black soybeans from non-irradiated black soybeans.