Preservation treatment of fresh raspberries by e-beam irradiation

E-beam irradiation was studied as a post-harvest treatment for red raspberries (Rubus idaeus L.). Microbial inactivation (natural microbiota and potential pathogenic bacteria) and bioactive properties (phenolic content, vitamin C content and antioxidant activity and cytotoxicity) of these fruits were evaluated before and after irradiation and during storage of 14 days at 4 °C. A reduction of 2 log CFU/g of mesophilic bacteria and 3 log CFU/g on filamentous fungi, and no detection of foodborne inoculated pathogens (3 log CFU/g) was achieved with an e-beam treatment at 3 kGy and during 7 days of refrigerated storage. Regarding bioactive properties, the results suggested that irradiation could preserve the phenolic content and antioxidant activity of raspberries through 7 days of cold storage, even though a decrease of 80% on ascorbic acid concentration was observed. Furthermore, no in vitro inhibitory effect on human cells lines was observed for the extracts from e-beam-treated raspberries. The overall results suggested that use of e-beam irradiation as post-harvest treatment of raspberries as an emergent, clean and environmental friendly process to extend the shelf-life of this fruit with safety and preservation of bioactivity.info:eu-repo/semantics/publishedVersio

Degradation of phenolic acids by gamma radiation as model compounds of cork wastewaters

The degradation by gamma radiation of four phenolic compounds (gallic acid, protocatechuic acid, vanillic acid and syringic acid) present in cork wastewaters was studied in several treatment conditions. The irradiations were performed under different pH (natural, 3, 7 and 10) and atmospheres (aerated, N2O and O2) for isolated and aqueous mixture solutions of standard phenolic acids. The degradation of the compounds was higher in isolated than in the mixture solutions indicating a protective effect in the quaternary mixture solution. The saturation with N2O promoted the highest degradation rates for all phenolic acids in the mixture. However, at natural pH and in air it was achieved degradation efficiencies>50% for gallic, vanillic and syringic acids in isolated and mixture solutions for a treatment dose of 20 kGy. It was verified that some of the compounds are a degradation product of the others, for example gallic acid was found to be a radiolytic product of syringic, vanillic and protocatechuic acids. Two different compounds were identified as radiolytic products of the studied phenolic acids, and their fragmentation pathways were proposed. The results highlighted that ionizing radiation could be used as clean technology for pollutants degradation using doses of 20 kGy.info:eu-repo/semantics/publishedVersio

Ionizing radiation technologies to increase the extraction of bioactive compounds from agro-industrial residues: a review

Due to the growing demand in society for healthier foods, scientific communities are searching and developing new ingredients. In this context, agro-industrial residues, which can have a negative impact on the environment, represent a natural source for bioactive compounds and their recovery can contribute to economic and environmental sustainability. Ionizing radiation is a clean and eco-friendly technology that can be used to improve the extraction of bioactive compounds. The aim of this review, after presenting general aspects about bioactive compounds in agro-industrial residues and radiation technologies, is to focus on the effects of ionizing radiation on the extraction of bioactive compounds from these residues and related bioactive properties. Irradiated residues were demonstrated to have enhanced bioactive characteristics that turn the prepared extracts suitable for applications in food industry, resulting in high-added-value products as well as reducing adverse impacts on the environment.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to C2TN (UIDB/04349/2020), CIMO (UIDB/00690/2020), and J.M. (SFRH/BD/136506/2018); L.B. thanks FCT for the national funding, P.I., through the institutional scientific employment program-contract; FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_ 6_E.info:eu-repo/semantics/publishedVersio

Padrões de inativação microbiana em hortelã-pimenta por radiação gama

As plantas podem ter várias aplicações, especialmente como aditivos alimentares e na promoção da saúde, como ingredientes em formulações de alimentos funcionais e nutracêuticos. Contudo, um dos maiores problemas associados ao seu consumo e comercialização é a sua contaminação microbiana. Esta contaminação pode ocorrer ao longo da colheita, processamento e distribuição. Deste modo, torna-se necessário encontrar uma solução viável para a conservação de plantas comestíveis ou medicinais e que cumpra as normas de segurança alimentar e farmacêutica. Atualmente, o processamento de ervas e especiarias por radiação ionizante é aceite como uma tecnologia segura e eficaz na descontaminação e desinfeção microbiana. Porém, a maioria dos estudos em irradiação de plantas incide nos efeitos da tecnologia nas propriedades químicas das plantas. O objetivo específico deste trabalho foi estudar os padrões de inativação por radiação gama da microbiota de Mentha x piperita (hortelã-pimenta). A metodologia seguida baseouse na determinação da carga microbiana (bactérias mesófilas e fungos filamentosos) de amostras secas de hortelãpimenta antes e após irradiação a várias doses de radiação gama (1,5 kGy e 10 kGy), recorrendo a métodos convencionais de cultura. As irradiações foram efetuadas num equipamento de Co-60 a um débito de dose de 1,2 kGy/h. Os resultados obtidos indicaram uma cinética de inativação não-linear (côncava) para a população bacteriana das plantas, e uma curva de sobrevivência linear para a população de fungos filamentosos. A análise da contaminação diferencial das amostras indicou após irradiação a 10 kGy, um decréscimo de 3 log em relação à carga bacteriana inicial de 5 log UFC/g, e uma redução de 2 log para a população fúngica inicial de 4 UFC/g. De referir, que não foi detetada a presença de coliformes totais nas amostras irradiadas a partir dos 1,5 kGy. Resumidamente, as eficiências máximas de inativação para as condições do estudo foram de 99,9% para a população bacteriana e de 99% para a população fúngica. Assim, este estudo sugere a tecnologia de irradiação, como um tratamento promissor e mais amigo do ambiente, pretendendo-se validar a sua aplicação na descontaminação/desinfeção microbiana de plantas secas com interesse alimentar e medicinal, sobre as quais este tipo de processamento e seus efeitos não se encontra documentado

Phenolic compounds from irradiated olive wastes: optimization of the heat-assisted extraction using response surface methodology

Olive pomace, an environmentally detrimental residue generated during olive oil extraction, contains bioactive compounds in demand by the food industry. To valorize this waste product a suitable yield for the extraction process is required. Heat-assisted extraction of bioactive compounds from olive pomace was optimized by a circumscribed central composite design and response surface methodology. Our previous studies indicated that irradiation could improve 2.4-fold the extractability of the main phenolic compounds from olive pomace. The effect of extraction time, temperature and solvent concentration on the yield of polyphenols from irradiated olive pomace at 5 kGy was tested. Hydroxytyrosol-1- -glucoside, hydroxytyrosol, tyrosol and caffeic acid were quantified by High Performance Liquid Chromatography to calculate the total polyphenol content. The optimal general conditions by RSM modeling were extraction time of 120 min, temperature of 85 C, and 76% of ethanol in water. Using these selected conditions, 19.04 1.50 mg/g dry weight, 148.88 8.73 mg/g extract of total polyphenols were obtained, representing a yield of 13.7%, which was consistent with the value predicted by the model. This work demonstrated the potential of residues from the olive oil industry as a suitable alternative to obtain compounds that could be used as ingredients for the food industry.This work was funded by the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to C2TN (UIDB/04349/2020), CIMO (UIDB/00690/2020), J.M. (SFRH/BD/136506/2018); L.B. thank the national funding by FCT, P.I., through the institutional scientific employment program-contract; and the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project OliveBIOextract (NORTE-01-0247-FEDER-049865). The GIP-USAL is funded by the Strategic Research Programs for Units of Excellence (ref CLU-2018-04) and Consejería de Educación de la Junta de Castilla y León (Project SA093P20).info:eu-repo/semantics/publishedVersio

Padrões de inactivação microbiana em hortelã-pimenta por radiação gama

As plantas podem ser utilizadas como aditivos alimentares e em benefício da saúde, como ingredientes em formulações de alimentos funcionais e nutracêuticos. Um dos principais problemas associado ao seu consumo e comercialização é a sua contaminação microbiana, que pode ocorrer ao longo da colheita, no processamento e na distribuição. Deste modo, torna-se necessário encontrar uma solução viável para a conservação de plantas comestíveis ou medicinais e que cumpra as normas de segurança alimentar e farmacêutica. Actualmente, o processamento de ervas e especiarias por radiação ionizante é reconhecido como uma tecnologia segura e eficaz na descontaminação e desinfecção microbiana. Porém, a maioria dos estudos em irradiação de plantas incide nos efeitos da tecnologia nas propriedades químicas das plantas. O objectivo específico deste trabalho foi estudar os padrões de inactivação por radiação gama da microbiota de Mentha x piperita (hortelã-pimenta). A metodologia seguida baseou-se na determinação da carga microbiana (bactérias mesófilas e fungos filamentosos) de amostras secas de hortelã-pimenta antes e após irradiação a várias doses de radiação gama (1,5 kGy a 10 kGy), recorrendo a métodos convencionais de cultura. As irradiações foram efectuadas num equipamento de 60Co a um débito de dose de 1,2 kGy/h. Os resultados obtidos indicaram uma cinética de inactivação não-linear (côncava) para a população bacteriana das plantas, e uma curva de sobrevivência linear para a população de fungos filamentosos. A análise da contaminação diferencial das amostras indicou após irradiação a 10 kGy, um decréscimo de 3 log em relação à carga bacteriana inicial de 5 log UFC/g, e uma redução de 2 log para a população fúngica inicial de 4 UFC/g. De referir, que não foi detectada a presença de coliformes totais nas amostras irradiadas a partir dos 1,5 kGy. As eficiências máximas de inactivação observadas nas condições do estudo foram de 99,9% para a população bacteriana e de 99% para a população fúngica. Assim, este estudo sugere a tecnologia de irradiação, como um tratamento promissor e mais amigo do ambiente, pretendendo-se validar a sua aplicação na descontaminação/desinfecção microbiana de plantas secas com interesse alimentar e medicinal, sobre as quais este tipo de processamento e seus efeitos não se encontra documentado.PRODER - Projecto AROMAP e FCT (Portugal) RECI/AAG-TEC/0400/2012 pelo apoio financeiro à execução do trabalho e à empresa “MaisErvas - Aromáticas e Medicinais” (Portugal), pela disponibilização das amostras

Effects of gamma radiation on cork wastewater: Antioxidant activity and toxicity

A comprehensive assessment of the toxicity and antioxidant activity of cork boiling wastewater and the effects of gamma radiation on these parameters was performed. Antioxidant activity was evaluated using different methodologies as DPPH radical scavenging activity, reducing power and inhibition of ß-carotene bleaching. The results have shown that gamma radiation can induce an increase on the antioxidant activity of cork boiling wastewater. Toxicity tests were performed to access the potential added value of the irradiated wastewaters and/or minimization of the impact for discharge in the environment. Two different methods for toxicity evaluation were followed, bacterial growth inhibition test and cytotoxicity assay, in order to predict the behavior of different cells (prokaryotic and eukaryotic) in the presence of cork wastewater. Non-treated cork boiling wastewater seemed to be non-toxic for prokaryotic cells (Pseudomonas fluorescens and Bacillus subtilis) but toxic for eukaryotic cells (A549 human cells and RAW264.7 mouse cells). The gamma radiation treatment at doses of 100 kGy appeared to increase the toxicity of cork compounds for all tested cells, which could be related to a toxic effect of radiolytic products of cork compounds in the wastewaters.This work was supported by Fundação para a Ciência e a Tecnologia (FCT, Portugal) through financial support of RECI/AAG-TEC/0400/2012 “Application of Ionizing Radiation for a Sustainable Environment” project. C2TN/IST authors gratefully acknowledge the FCT support through the UID/Multi/04349/2013 project. The authors are also grateful to International Atomic Energy Agency (Contract No. 16513) and to the cork industry (Amorim S.A) for allowing us to collect all the samples necessary for the accomplishment of this work.info:eu-repo/semantics/publishedVersio

The use of gamma radiation for extractability improvement of bioactive compounds in olive oil wastes

Olive pomace is an environmentally detrimental waste from olive oil industry, containing large amounts of bioactive compounds that might be used by the food industry. In this work, the effects of gamma radiation on phenolic compounds and bioactive properties (antioxidant, antimicrobial activities and hepatotoxicity) of Crude Olive Pomace (COP) and Extracted Olive Pomace (EOP) extracts were evaluated. Hydroxytyrosol was the main phenolic compound identified in both olive pomace extracts (24–25 mg/g). The gamma radiation treatment of olive pomace improved at least 2-fold the extractability of phenolic compounds. Moreover, results suggested that gamma radiation at 5 kGy increased the antioxidant activity in EOP, while keeping the ability to protect erythrocytes against oxidation-induced haemolysis. Gamma radiation at 5 kGy could be a suitable technology for olive oil pomaceswaste valorization, contributing to enhance extraction of phenolic compounds and bioactive properties, especially when applied on extracted material.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to C2TN UID/Multi/04349/2019, CIMO UID/AGR/00690/2019, J. Madureira [SFRH/BD/136506/2018]; L. Barros, J. Pinela and M.I. Dias thank the national funding by FCT, P.I., through the institutional scientific employment programcontract; FEDER-Interreg España-Portugal program for financial support through the project 0377_Iberphenol_6_E; “UCASUL - União de Cooperativas Agrícolas do Sul” agro industrial cooperative for providing the samples; to Technological Unit of Radiosterilization (University of Lisbon) for the samples irradiation; and to Molecular Materials Synthesis Laboratory (responsible Researcher Dr. Dulce Belo, C2TN) for the solvent evaporations.info:eu-repo/semantics/publishedVersio

Assessment of gamma radiation effects on antioxidant activity of cork wastewater

Cork cooking wastewater results from the process of boiling cork planks. It is an aqueous and complex dark liquor with high concentration of phenolic compounds such as phenolic acids and tannins [1, 2], which are known for their high antioxidant activity. The aim of this work is to perform a compreensive assessment of the effects of gamma radiation on the antioxidant activity of cork cooking water. The irradiation experiments were carried out at room temperature in a Co-60 experimental equipment (Prescisa 22, Graviner, Lda, UK), with an activity of 140 Tbq (3.77 kCi) and at a dose rate of 1.5 kGy/h, located at the Centro de Ciências e Tecnologias Nucleares (Portugal). Samples of wastewater were irradiated at. three distinct. doses (10, 20 and 50 KGy) and the antioxidant activity was evaluated by in vitro assays based on different mechanisms of action: DPPH radical scavenging activity, reducing power and inhibition of β-carotene bleaching. Antioxidant capacity was compared with the physico-chemical characterization [3) of cork wastewater - Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS) and Total Phenolic Content. (TP) - when exposed to gamma radiation. The obtained results point out that gamma radiation induces changes in complex compounds leading to an increase in the antioxidant capacity. These results demonstrate the potential of this technology in order to increase the added value of cork wastewaters.We are grateful to FCT (Portugal) by the supporting of RECI/AAG-TEC/0400/2012 "Application of lonizing Radiation for a Sustainable Environment" project and to lnternational Atomic Energy Agency (Austria) by the supporting of CRP 1539 - F23029 "Radiation Treatment of Wastewater for Reuse with Particular Focus on Wastewaters Containing Organic Pollutants"' project.info:eu-repo/semantics/publishedVersio

Gamma radiation induces degradation of phenolic acids

The aim of this work was to study the degradation by gamma radiation of four phenolic acids (gallic acid, protocatechuic acid, vanillic acid and syringic acid) that are recalcitrant pollutants present in cork wastewaters [1]. The irradiations were carried out at room temperature using a Co-60 experimental equipment, under different pH (natural, 3, 7 and 10) and atmospheres (aerated, N2O and O2) for isolated and aqueous mixture phenolic acids’ solutions. The applied absorbed doses were 5-20 kGy at a dose rate of 1.5 kGy/h. The degradation of phenolic acids was analyzed by HPLC-DAD and the identification of radiolytic products was carried out by LCDAD- ESI/MS. The obtained results indicated that the degradation of the compounds was higher in isolated than in the mixture solutions suggesting a protective effect in the quaternary mixture solution. The N2O saturation promoted the highest degradation rates in the mixture, at natural pH, however in aerated conditions it was achieved degradation efficiencies >50% for a treatment dose of 20 kGy. Concerning the identification of the radiolytic products two different compounds were identified (trihydroxybenzoic acid, [M-H]- at m/z 169, and methyl gallate, [M-H]- at m/z 183) as radiolytic products of the studied phenolic acids (Figure 1). The degradation mechanisms of the studied phenolic acids was proposed. The results highlighted that ionizing radiation could be used as clean technology for pollutants degradation using doses of 20 kGy.The authors are grateful to the FCT support: C2TN (UID/Multi/04349/2013, RECI/AAG-TEC/0400/2012), CIMO (UID/AGR/00690/2013), L. Barros contract; FEDER-Interreg España-Portugal programme (0377_Iberphenol_6_E).N/