139 research outputs found
Target specific post-harvest treatment by gamma radiation for the microbial safety of dried Melissa officinalis and Aloysia citrodora
This study aimed to assess a specific gamma radiation dose to be applied as a post-harvest process to guarantee the microbial safety of two medicinal plants, Melissa officinalis and Aloysia citrodora. Dried plants treated with gamma radiation indicated that a dose of 5 kGy could be applied as a post-harvest treatment process of M. officinalis and A. citrodora, assuring the microbial safety of dried medicinal plants and lowering the potentiality of deleterious effects on plantsâ quality attributes. This will enhance the safety and quality of the dried plants to be used as raw materials in industrial applications.The authors are grateful to project PRODER nÂș 53515, AROMAP, for
financial support of the work. The authors thank to âMaisErvas -
AromĂĄticas e Medicinaisâ company for supplying the samples. C2TN/
IST authors gratefully acknowledge the FCT support through the RECI/AAG-TEC/0400/2012 and UID/Multi/04349/2013 projects.info:eu-repo/semantics/publishedVersio
Gamma irradiation in ochratoxin A control
ICFC 2017 - International Conference on Food Contaminants (Book of Abstracts)Ochratoxin A (OTA) is one of the main mycotoxins found in food. Gamma radiation is used
for preserving foods since it inactivates pathogens. The effect of irradiation on mycotoxins
has been studied but results are contradictory. The different matrices and conditions used
by several authors may have influenced reported results. The aim of this work was to study
the effects of gamma radiation in OTA in order to evaluate its applicability in foods. OTA
was irradiated in its dry form, in aqueous and in methanolic solutions to evaluate the water
role in OTA irradiation. Then, OTA contaminated food matrices, such as wheat flour, grape
juice and wine, were irradiated.In aqueous solutions, high degradation of OTA (â„90%) was
obtained with gamma radiation doses as low as 2.5kGy. However, in dried samples, OTA
was found extremely resistant to radiation doses of up to 10kGy. In this case, water was a
determinant factor for the effectiveness of irradiation process. In the assays with food
matrices, radiation doses greater than 10kGy were needed to achieve higher reductions of
OTA, being eliminated just 24%. It was also observed that OTA elimination was higher in
wheat flour with higher moisture contents but the elimination of OTA in grape juice and
wine were not higher than those observed in wheat flour. It is concluded that OTA is very
sensitive to irradiation in water solutions but resistant in its dry form and in food matrices.
Due to the low elimination percentage observed, it can be considered that gamma radiation
is not a suitable technology for the elimination of OTA from foods.Thalita Calado and LuĂs Abrunhosa received support by grants SFRH/BD/79364/2011 and
UMINHO/BPD/51/2015 from FCT, respectively. CEB gratefully acknowledge FCT support through projects
UID/BIO/04469/2013, NORTE-01-0145-FEDER-000004, and RECI/BBB-EBI/0179/2012. The C2TN/IST
authors gratefully acknowledge their FCT support through projects RECI/AAG-TEC/0400/2012 and
UID/Multi/04349/2013.info:eu-repo/semantics/publishedVersio
Aflatoxins detoxification by gamma irradiation
[Excerpt] Mycotoxins are secondary toxic metabolites of filamentous fungi. Aflatoxins (AFs) are produced to Aspergillus species such as A. flavus and A. parasiticus. These fungi are ubiquitous in nature and usually found on agricultural commodities. Therefore, AFs are encountered in many important foodstuff, including wheat, rice, maize, peanuts, sorghum, pearl millet, spices, oilseeds, tree nuts and milk. Due to the high toxicity of AFs, many methods have been studied to reduce or eliminate these mycotoxins from food and feed. Gamma irradiation is one technology that has been investigated with promising results. The aims of this study were (I) to study the effect of gamma radiation on aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 (II) to evaluate the effect of the presence of water on AFs degradation during the irradiation process; and (IV) to evaluate the cytotoxicity of radiolytic products formed. (...
Castanea sativa shells and fruits: Compositional analysis by proton induced X-ray emission
Chestnut fruits, from Castanea sativa Miller species, have been previously characterized mainly to study the
nutritional and biochemical parameters, with mineral contents receiving less attention from the researchers,
although these minerals are essential for several mechanisms in human body. In this study, a detailed elemental
compositional analysis was performed using Proton Induced X-ray Emission (PIXE) to characterize two varieties
of Castanea sativa Miller chestnuts (Longal and Judia). This study comprises the composition of the outer shells
(pericarp), inner shells (episperm) and the edible fruits. From our knowledge, this is the first time that the
presence of up to 20 elements on the shells and the fruits are reported. Furthermore, by PIXE it was possible to
quantify them, allowing significant improvements in the assessment of chestnuts composition. Essential and nonessential
elements were quantified on a food item that is used mainly for human consumption but it is also
incorporated in animal feeding.Authors acknowledge R. Pinheiro for sample preparation. This work
was developed within the Coordinated Research Project D61024
ââDevelopment of New Applications of Machine Generated Food
Irradiation Technologiesââ financed by the International Atomic Energy
Agency (IAEA). IST authors gratefully acknowledge the FCT (Fundação
para a CiĂȘncia e a Tecnologia) support through the UID/Multi/04349/
2013 and UID/FIS/50010/2013 projects.info:eu-repo/semantics/publishedVersio
Ionizing radiation for food preservation processing: less or in excess?
The industrial use of ionizing radiations, such as gamma and electron beam (e-beam) radiation, is regulated and authorized by international organizations (EU, EFSA, IAEA, FAO, WHO) for several purposes: medical devices sterilization, materials modification, heritage preservation and food decontamination. However, there is mistrust among the general public regarding food irradiation due to the wrong association with an induced radioactivity on the product. Therefore, several obstacles have to be overcome in order to promote food irradiation as a safe and useful application of ionizing radiations. The increasing demand for safe and healthy food is another issue that could help to promote the use of these technologies. In Europe, the preservation of food by irradiation is strongly regulated but is still not very popular, in spite of several food safety issues, such as pathogens contamination or insectsâ infestation that could be easily solved by an environment friendly technology, without the use of chemical fumigants. We will present briefly the recent state-of-art of food irradiation research in Portugal, selecting the main results of three collaborative projects funded by national and international agencies, regarding the effects of gamma radiation on physical and chemical parameters of selected materials: fruits, vegetables and mushrooms, toward the objective to keep the focus on this valuable tool for food processing.To the Projects/Agencies that supported this research: Portuguese Government and E.U. funds: PRODER/FEADER/EU (AROMAP Project); Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (PEst-OE/AGR/UI0690/2014), and C2TN (RECI/AAG-TEC/0400/2012 and UID/Multi/04349/2013 projects); International Atomic Energy Agency (IAEA) Coordinated Research Project CRP-D6-RC-1163.2 and IAEA Research contract 19220.info:eu-repo/semantics/publishedVersio
Gamma irradiation effects on microbial inactivation and antioxidant activity of Melissa officinalis
Many herbal products are traditionally being used as medicines and nutraceuticals in different regions of the world (Kumar et al., 2010). This increased consumption of natural products has become a public health problem. The concern in the safety of these products is due, in part, to the possible presence of pathogenic bacteria and fungi producing mycotoxins (Prado et al., 2009). The medicinal plant, also known as lemon balm, analysed in the present study is used in traditional medicine to treat or to relieve nervous disturbance of sleep and functional gastrointestinal disorders although there are a great variety of phytopharmaceutical preparations containing this plant or its extracts (Kennedy et al., 2002; LĂłpez et al., 2009). Consequently the evaluation of the hygienic quality of medicinal plants, as well the use of decontamination methods are significant steps towards the consumer safety and therapeutical efficiency (Soriani et al., 2005). The obtained results suggested that the gamma irradiation treatment could be advantageous in improving microbial safety of M. officinalis with the potential added-benefit of increasing its antioxidant content. The effect of higher irradiation doses on M. officinalis will be further investigated, in an attempt to augment the reduction of the microbial population."MaisErvas - AromĂĄticas e Medicinais" company for providing the samples
Food irradiation as a key to reduce food waste and guarantee food safety
Food waste is being in the focus of recent global policies, to tackle food scarcity and to overcome ânutritional povertyâ in several countries. Otherwise, a global food market is being the key to make available several products to different populations. These vectors for food policy must be supported by several orientations, to attain their final objective: better and enough food for the world population. For that, different post-harvest processing technologies are making their fundamental contribute. Among that, the preservation of food by irradiation, a physical process that does not use chemicals, is making its way in several countries, to accept imported or exported products without pests (insects), without foodborne pathogens, and also to extend the shelf life of processed products, stopping enzymatic degradation and reducing microorganisms that contribute for food spoilage. We have been studying the effects of gamma and e-beam radiation for food preservation of several Mediterranean products, including chestnuts, mushrooms and aromatic plants, berries and tomatoes, using an experimental gamma chamber with 60Co sources and an electron accelerator with the maximum energy of 10 MeV. And here we present these technologies, their limitations and advantages, the effects on relevant properties of food (e.g. color, texture, nutritional parameters), and question why food preservation by irradiation is underused, since its first use has more than 100 years and its first industrial application has more than 50 years.FCT (Portugal), FEDER PT2020 (UID/AGR/00690/2019), C2TN (UID/Multi/04349/2013), IAEA CRP D61024.info:eu-repo/semantics/publishedVersio
Descontaminação e conservação de plantas aromåticas e medicinais por irradiação
Devido às contaminaçÔes a que as plantas são expostas e
tendo em conta as exigĂȘncias de segurança e qualidade por
parte das indĂșstrias alimentar e farmacĂȘutica, Ă© indispensĂĄvel o uso de processos que garantam a segurança microbiolĂłgica do material processado, sem por em causa as suas principais caracterĂsticas.ProDer nÂș 5315 - AROMA
Gamma radiation effects on microbial inactivation of two medicinal plants
The consumption of natural products has become a public health problem, since these medicinal
teas are prepared using natural plants without an effective hygienic and sanitary control. The
aim of this study was to assess the effects of gamma radiation, on the microbial burden of two
medicinal plants: Melissa officinalis and Lippia citriodora.
Dried samples of the two plants were irradiated at a Co-60 experimental equipment. The applied
gamma radiation doses were 1, 3, and 5 kGy at a dose rate of 1.34 kGy/h. Non-irradiated
samples followed all the experiments. Bacterial and fungal counts were assessed before and
after irradiation by membrane filtration method. Challenging tests with Escherichia coli were
performed in order to evaluate the disinfection efficiency of gamma radiation treatment.
Characterization of M. officinalis and L. citriadora microbiota indicated an average bioburden
value of 102 CFU/g. The inactivation studies of the bacterial mesophilic population of both dried
plants pointed out to a one log reduction of microbial load after irradiation at 5 kGy. Regarding
the fungal population, the initial load of 30 CFU/g was only reduced by 0.5 log by an irradiation
dose of 5 kGy. The dynamics with radiation doses of plants microbial populationâs phenotypes
indicated the prevalence of gram-positive rods for M. officinalis before and after irradiation, and
the increase of the frequency of gram-negative rods with irradiation for L. citriadora. Among
fungal population of both plants, Mucor, Neoscytalidium, Aspergillus and Alternaria were the
most isolated genera. The results obtained in the challenging tests with E. coli on plants pointed
out to an inactivation efficiency of 99.5% and 99.9% to a dose of 2 kGy, for M.officinalis and L.
citriadora, respectively.
The gamma radiation treatment can be a significant tool for the microbial control in medicinal
plants.The authors are grateful to project PRODER nÂș 53515, AROMAP,
for financial support of the work. The authors thank to "MaisErvas - AromĂĄticas e Medicinais"
company for supplying the samples. The authors are grateful to FCT (RECI/AAGTEC/
0400/2012) for financial support
Oxidation of clofibric acid in aqueous solution using a non-thermal plasma discharge or gamma radiation
In this work, we study degradation of clofibric acid (CFA) in aqueous
solution using either ionizing radiation from a Co source or a
non-thermal plasma produced by discharges in the air above the solution. The
results obtained with the two technologies are compared in terms of
effectiveness of CFA degradation and its by-products. In both cases the CFA
degradation follows a quasi-exponential decay in time well modelled by a
kinetic scheme which considers the competition between CFA and all reaction
intermediates for the reactive species generated in solution as well as the
amount of the end product formed. A new degradation law is deduced to explain
the results. Although the end-product CO was detected and the CFA
conversion found to be very high under the studied conditions, HPLC analysis
reveals several degradation intermediates still bearing the aromatic ring with
the chlorine substituent. The extent of mineralization is rather limited. The
energy yield is found to be higher in the gamma radiation experiments.Comment: 25 pages, 7 figure
- âŠ