Assessing the effects of gamma irradiation and storage time in energetic value and in major individual nutrients of chestnuts.

Chestnut (Castanea sativa Miller) is an important food resource all over the world. In the present study, it is intended to evaluate if the application of gamma irradiation doses < 3 kGy maintain chestnuts chemical and nutritional profiles unaffected. Furthermore, possible interactions among irradiation dose and storage time were accessed using linear discriminate analysis (LDA). The nutritional composition was evaluated through determination of proteins, fat, ash, carbohydrates and energetic value. The chemical composition was focused in the main nutrients found in chestnuts: sugars- sucrose, fatty acids- palmitic, oleic, linoleic and linolenic acids, tocopherols- Y-tocopherol. The obtained results seem to indicate that the irradiation treatment did not affect the nutritional and chemical quality of chestnut fruits. Otherwise, storage time exerted more evident influence in those parameters. The application of gamma irradiation emerges as a promising technology for chestnuts chemical quality, but food safety issues has to be evaluated in order to recommend its application as a useful conservation alternative

Influence of gamma irradiation in the antioxidant potential of chestnuts (Castanea sativa Mill.) fruits and skins

As seasonal products chestnuts have to be postharvest treated to increase their shelf-life. The most common preservation method for chestnuts is the chemical fumigation with methyl bromide, a toxic agent that is under strictly use under Montreal Protocol due to its adverse effects on human health and environment. Food irradiation is a possible feasible alternative to substitute the traditional quarantine chemical fumigation treatment. This preliminary study evaluated the influence of gamma irradiation in the antioxidant potential of chestnut fruits and skins, through several chemical and biochemical parameters. The bioactive compounds (phenolics and flavonoids) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power and inhibition of B-carotene bleaching capacity were determined. The obtained results seem to indicate that the storage favoured chestnuts antioxidant potential. Furthermore, the application of gamma irradiation also seems to be advantageous for antioxidant activity, independently of the dose used (0.27 ± 0.04 kGy or 0.54 ± 0.04 kGy)

Effects of gamma irradiation on the chemical composition and antioxidant activity of Lactarius deliciosus L. wild edible mushroom

TThe short shelf-life of mushrooms is an obstacle to the distribution and marketing of the fresh product. There has been extensive research on finding the most appropriate technology for mushrooms preservation and a particular interest arises for wild species. Treatment by irradiation emerges as a possible conservation technique that has been tested successfully in several food products. Herein, the effects of gamma irradiation on Lactarius deliciosus (L. ex Fr.) S. F. Gray chemical composition and antioxidant activity were evaluated in samples submitted to different storage periods (0, 4 and 8 days) at 4 °C. The irradiation treatments were performed in a Co-60 experimental equipment. Nutritional value was accessed by macronutrients analysis and determination of energetic value; fatty acid, sugar and tocopherol profiles were determined by gas chromatography– flame ionization detector, high-performance liquid chromatography (HPLC) refractive index and HPLC fluorescence, respectively. The antioxidant activity was evaluated through radical scavenging activity, reducing power, lipid peroxidation inhibition and phenolics content. The obtained data show that, until 1 kGy, gamma irradiation might provide a useful alternative to ensure the quality and extend the life of mushrooms, since its effects on macronutrients, energetic value, tocopherols and antioxidant activity EC50 values were less significant than the changes caused by storage time. Moreover, the chemical and nutritional composition was similar in irradiated and non-irradiated L. deliciosus samples

Low dose gamma-irradiation as a suitable solution for chestnut (Castanea sativa Miller) conservation: effects on sugars, fatty acids and tocopherols

Along with dehydration, the development of insects and microorganisms is the major drawback in chestnut conservation. Irradiation has been regaining interest as an alternative technology to increase food products shelf-life. In the present work, the effects of low dose gamma irradiation on sugars, fatty acids and tocopherols composition of chestnuts stored at 4 ºC for different storage periods (0, 30 and 60 days) was evaluated. The irradiations were performed in a 60Co experimental equipment, for 1 h (0.27 +/- 0.04 kGy) and 2 h (0.54 +/- 0.04 kGy). Changes in sugars and tocopherols were determined by high performance liquid chromatography (HPLC) coupled to refraction index (RI) and fluorescence detections, respectively, while changes in fatty acids were analysed by gas-chromatography coupled to flame ionization detection (GC-FID). Regarding sugars composition, storage time proved to have higher effect than irradiation treatment. Fructose and glucose increased after storage, with the corresponding decrease of sucrose. Otherwise, tocopherols content was lower in non-irradiated samples, without a significant influence of storage. Saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids levels were not affected neither by storage nor irradiation. Nevertheless, some individual fatty acids concentrations were influenced by one of both factors, such as the increase of palmitic acid in irradiated samples or the decrease of oleic acid after 60 days of storage. Overall, the assayed irradiation doses seem to be a promising alternative treatment to increase chestnuts shelf-life, without affect the profile and composition in important nutrients

Chemometric characterization of gamma irradiated chestnuts from Turkey

Chestnut (Castanea sativa Miller) is a valuable natural resource, with high exportation levels. Due to their water content, chestnuts are susceptible to storage problems like dehydration or development of insects and microorganisms. Irradiation has been revealing interesting features to be considered as an alternative conservation technology, increasing food products shelf-life. Any conservation methodology should have a wide application range. Hence, and after evaluating Portuguese cultivars, the assessment of irradiation effects in foreign cultivars might act as an important indicator of the versatility of this technology. In this work, the effects of gamma irradiation (0.0, 0.5 and 3.0 kGy) on proximate composition, sugars, fatty acids (FA) and tocopherols composition of Turkish chestnuts stored at 4 ºC for different periods (0, 15 and 30 days) were evaluated. Regarding proximate composition, the storage time (ST) had higher influence than irradiation dose (ID), especially on fat, ash, carbohydrates and energetic value. Sucrose exhibited similar behavior in response to the assayed ST and ID. The prevalence of ST influence was also verified for FA, tocopherols and sucrose. Lauric, palmitoleic and linolenic acids, were the only FA that undergone some differences with ID. Saturated, monounsaturated and polyunsaturated fatty acids levels were not affected neither by storage nor irradiation. α-Tocopherol was the only vitamer with significant differences among the assayed ST and ID. Overall, Turkish cultivars showed a compositional profile closely related with Portuguese cultivars, and seemed to confirm that gamma irradiation in the applied doses did not change chestnut chemical and nutritional composition

Application of gamma and electron beam irradiation for chestnuts conservation

Due to the distribution of low quality products, adulteration, counterfeit on the Ukrainian market, the widening of export-import supplies, it is too important to develop criteria and methods for the identification domestic and exported food products, detection of adulteration, techniques and methods assessing quality and early spoilage screening of food products using modern express methods of analysis. Such method is an electronic nose system based on chemical sensors, for example, piezoelectric quartz microweighing, combined with complex computer algorithms registration, processing and decision making («artificial intelligence»). Odor is one of the most significant parameters among the sensory properties of foods. The representative flavor of volatile compounds, so-called fingerprint, may provide knowledge about safety and particular characteristic of food, acting sometimes as an indicator of process mistake as well. Off-flavors may include substances originating from the metabolism of spoilage microorganisms, bacteria and fungi; which may naturally or accidentally contaminate the products during their production. Electronic noses (EN) are instruments based on an array of semi low selective sensors that are selected on the chemical affinity to individual components of the analyzed gas mix and vapors and pattern recognition methods. ENs have been applied in various food contexts such as process monitoring, freshness evaluation, shelf-life investigation, authenticity determination, and product traceability. The object of our research is express methods development of identification, estimation of quality and early spoilage screening of dairy and meat products using multisensory electronic nose system based on piezosensors. The absolute advantages of electronic sensory analyzers are their versatility, portability, ability to automate measurements and interpretation of signals, reproducibility of results.Financial support of ON.2/QREN/EU Project no.13198/2010, Fundação para a Ciência e a Tecnologia (FCT, Portugal) and COMPETE/QREN/EU (CIMO strategic project PEst-OE/AGR/UI0690/2011). A.L. Antonio, L. Barros and J.C.M. Barreira also thank to FCT, POPH-QREN and FSE for their grants (SFRH/PROTEC/67398/2010, SFRH/BPD/4609/2008 and SFRH/BPD/72802/2010, respectively)

Fatty acids profiles as a tool to distinguish Y-irradiated food products: a transnational study based on Castanea sativa fruits

Chestnut (Castanea sativa) is an important food resource in severa l count ries. Portuga l and Turkey are among the major European producers. Due to the high value of chestnuts, there is a need for conservat ion methodologies that allow the complete maintenance of t heir properties. Food irradiation is a possible alternative to substitute the traditional quarantine chemical fumigation treatment [1,2). The fatty acid (FA) composition of chestnuts is important from several perspectives, including (1) nutritional quality; (2) possible health benefits offered by monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids {PUFA); {3) desirable flavors are often attributed to several FA; (4) contribution to texture; and (5) importance in keeping quality (shelf life). Therefo re, in addition to their health effects, fatty acids play an important role in ch estnut conservation quality. These lipidic compounds might be affected by the applied irradiation dose; oth erwise, the dose must be high enough to assure the elimination of the biological risks. Hence, it is primarily essential to define the t hreshold values that prevent the development of undesirable physico-chemical changes. Herein, the influence of gamma irradiation dose (0.50 and 3.00 kGy) over the FA profiles of Portuguese and Turkish chestnuts was evaluated by gas-chromatography coupled to flame ionization detection. Chestnuts from both countries revealed an identical profile, comprising C8:0, C12:0, C14:0, C16:0, C16:1, C17:0, C18 :0, C18:1n9, C18:2n6, C18:3n3, C20:0, C20:1n11, C20:2n11, C20:3n3+C21:0, C22:0 and C24:0 (C15 :0 was only found in Portuguese cultivars). Overall, the tested doses did not affect greatly the FA profiles. Nevertheless, some particular differences regarding individual FA were det ected allowing a better comprehension about the chemical interactions induced by irradiation treatment

Plasma electrolytic oxidation (PEO): An alternative to conventional anodization process

Due to the need to develop methods that optimize the surface properties of lightweight alloys such as aluminum, titanium, and magnesium and align with contemporary requirements of the 21st century, such as enhanced environmental and sanitary efficiency, the plasma electrolytic oxidation (PEO) process stands out as a comprehensive solution. This process can develop oxide coatings on the mentioned alloys, which exhibit superior physical and chemical properties compared with conventional methods. Since 2010, research in this area has been conducted with real-world applications. Recent studies have adopted experimental design approaches to optimize parameters to reduce operational costs and make the technology more accessible. The present study conducted a comparative analysis between treatments performed by conventional methods and by plasma processes, highlighting the most promising results

Efeito protector da radiação γ nos níveis de vitamina E em Castanea sativa

A vitamina E é o nome comum de um grupo de compostos que incluem tocoferóis e tocotrienóis. Estes compostos são antioxidantes lipofílicos com efeitos importantes no organismo nomeadamente, na prevenção do envelhecimento, no fortalecimento do sistema imunitário, na redução do risco de cancro e de infecções por HIV, ou até no tratamento da doença de Parkinson. Em particular, os tocoferóis podem contribuir para a diminuição dos efeitos adversos em doenças inflamatórias tais como artrite reumatóide ou hepatite [1-4]. O -tocoferol e o seu metabolito 2,7,8-trimetil-2-(β-carboxietil)-6-hidroxicromano provaram já ter actividade anti-inflamatória, constituindo alternativas promissoras aos fármacos utilizados como inibidores da ciclo-oxigenase (COX-2), uma enzima-chave em muitos processos inflamatórios. Da vitamina E presente na castanha (Castanea sativa), cerca de 95% está sob a forma de -tocoferol, podendo este fruto ser considerado um alimento funcional [5]. Neste estudo foi avaliado o efeito da radiação na concentração de tocoferóis, analisados por cromatografia líquida de alta eficiência (HPLC) acoplada a detecção por fluorescência. Verificou-se que a radiação exerceu um efeito protector nos níveis de -tocoferol, uma vez que nas amostras não irradiadas a concentração desta molécula diminui ao longo do tempo de armazenamento. A irradiação poderá ser uma alternativa promissora aos actuais tratamentos aplicados para o prolongamento do tempo de prateleira deste fruto, não afectando compostos de elevado valor nutracêutico como é o caso do -tocoferol aqui evidenciado.projecto ON.2/QREN/UE nº 13198/2010 pelo apoio financeiro. J.C.M. Barreira, L. Barros e A.L. Antonio agradecem à FCT, POPH-QREN e FSE pelas bolsas SFRH/BPD/72802/2010, SFRH/BPD/4609/2008 e SFRH/PROTEC/67398/2010

Chemometric characterization of gamma irradiated chestnuts from Turkey

Chestnuts (Castanea sativa Miller) is a valuable natural resource, with high exportation levels. Due to their water content, chestnuts are susceptible to storage problems like dehydration or development of insects and microorganisms. Irradiation has been revealing promising features to be considered as an alternative conservation technology, for Portugese cultivars. Hence, the assessment of irradiation effects in foreign cultivars might act as an important indicator of the versatility of this technology. In this work, the effects of gamma irradiation (0.0, 0.5 and 3.0 kGy) on proximate composition, sugars, fatty acids and tocopherols composition of Turkish chestnuts stored at 4 ºC for different periods (0, 15 and 30 days) was evaluated. Regarding proximate composition, the storage time (ST) had higher influence than irradiation dose (ID), especially on fat, ash, carbohydrates and energetic value. Sucrose exhibited similar behavior in response to the assayed ST and ID. The prevalence of ST influence was also verified for fatty acids (FA), tocopherols and sucrose. Lauric, palmitoleic and linolenic acids, were the only FA that undergone some differences with ID. Saturated, monounsaturated and polyunsaturated fatty acids levels were not affected neither by storage nor irradiation. α-Tocopherol was the only vitamer with significant differences among the assayed ST and ID. Overall, our results confirm that gamma-irradiation is a promising conservation methodology, without inducing changes in chestnut chemical and nutritional composition