Untitled

Funder

Organizational Unit

Publications

Target specific post-harvest treatment by gamma radiation for the microbial safety of dried Melissa officinalis and Aloysia citrodora

Publication . Meneses, Márcia; Antonio, Amilcar L.; Cabo Verde, Sandra

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 plants’ quality attributes. This will enhance the safety and quality of the dried plants to be used as raw materials in industrial applications.

2021Journal article

Open access

Food irradiation as a key to reduce food waste and guarantee food safety

Publication . Antonio, Amilcar L.; Ferreira, Isabel C.F.R.; Santos, Pedro M.P.; Cabo Verde, Sandra

Food waste is being in the focus of recent global policies, to tackle food scarcity and to overcome “nutritional poverty” 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.

2019Conference object

Open access

Extraction of mushrooms relevant compounds through gamma and electron beam irradiation

Publication . Fernandes, Ângela; Antonio, Amilcar L.; Santos, Pedro M.P.; Cabo Verde, Sandra; Barreira, João C.M.; Oliveira, Beatriz; Martins, Anabela; Ferreira, Isabel C.F.R.

Irradiation technologies are being used by the food industry as an alternative to other preservation processes. Its impact in minor compounds or different food matrices is still an open field. The use of irradiation to improve bioactive properties has been reported as a result of an increase in the levels of phenolic compounds in the extracts obtained from cooked and derived plant products. Previous results [1] indicated higher values of phenolic compounds concentration on irradiated food products compared with those found in non-irradiated samples. In this work, the effect of gamma and electron beam radiation processing on fresh and dried mushroom compounds extractability was studied. The mushroom samples were bought directly from the producer and divided in two groups, fresh to be immediately irradiated and to dry, before irradiation with gamma and electron beam (doses 0, 1, 2 and 5 kGy), that was carried out in the irradiation facilities of C2TN (Lisbon, Portugal). The irradiated fresh samples were immediately lyophilized for subsequent analysis by High Performance Liquid Chromatography (HPLC) and the dried samples were grounded into powder also to be analyzed after irradiation. The results were compared with a control (non-irradiated sample), obtaining the yield for each irradiation process (gamma and e-beam) or sample type (fresh or dried). Food irradiation besides being a preservation technology, suggested to promote food bioactive compounds.

2017Conference object

Open access

Avaliação dos efeitos da irradiação na composição química e bioatividade de plantas usadas na indústria farmacêutica e/ou alimentar

Publication . Pereira, Eliana; Barros, Lillian; Antonio, Amilcar L.; Bento, Albino; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.

Algumas plantas são uma fonte natural de compostos bioativos, tais como polifenóis, vitaminas, carotenóides e ácidos gordos insaturados. Esta diversidade de biomoléculas permite a sua utilização em diversas áreas, especialmente como aditivos alimentares e ingredientes naturais para promoção da saúde. Estes fitoquímicos têm sido utilizados na industria farmacêutica, bem como na formulação de suplementos dietéticos, alimentos funcionais e nutracêuticos. No entanto, a utilização de matérias-primas de boa qualidade microbiológica é um dos requisitos essenciais na indútria, uma vez que os microrganismos podem contaminar o produto final, levando à sua deterioração. Assim, a irradiação é creditada para que a sua aplicação seja permitida em ingredientes secos, sendo cada vez mais reconhecida mundialmente, devido à eficiência na redução das perdas causadas por processos fisiológicos naturais (brotamento, maturação e envelhecimento), para eliminar ou reduzir microorganismos, parasitas e pragas, sem que ocorra qualquer alteração (química ou organoléptica) no alimento, tornando-o mais seguro para o consumidor [1-3]. O objetivo deste estudo foi avaliar os efeitos da aplicação de diferentes doses de radiação gama e feixe de eletrões na composição química e bioatividade de várias plantas (Ginkgo biloba L., Melissa officinalis L., Melittis melissophyllum L., Mentha piperita L., Aloysia citrodora Palàu, Arenaria montana L. e Thymus vulgaris L.).

2016Conference object

Open access

Evaluation of gamma-irradiated aromatic herbs: Chemometric study of samples submitted to extended storage periods

Publication . Pereira, Eliana; Antonio, Amilcar L.; Barreira, João C.M.; Cabo Verde, Sandra; Barros, Lillian; Oliveira, Beatriz; Ferreira, Isabel C.F.R.

The preserving capacity of gamma radiation (10 kGy) on the chemical, nutritional and antioxidant components of Aloysia citrodora Paláu, Melissa officinalis L., Melittis melissophyllum L. and Mentha piperita L., stored for 12 and 18 months, was evaluated. Despite the maintenance of the main characteristics during the first 12 months of storage, the additional 6 months induced several significant changes in individual compounds. In general, the analyzed species reacted dissimilarly throughout time, but it was possible to verify that the fatty acids, tocopherols and antioxidant capacity presented the most significant changes after 18 months of storage, inclusively in samples submitted to gamma radiation. In fact, the applied treatment (10 kGy) did not seem to be effective to prevent the decrease of free sugars, organic acids and tocopherols, especially considering the 18 months period. On the other hand, the evolution in color parameters indicated a greener color (yet slightly more yellow) among irradiated samples. Likewise, gamma radiation had a positive effect on oleic acid, β-carotene bleaching inhibition (in infusions), DPPH scavenging activity and reducing power (in methanolic extracts). Nevertheless, it might be generally concluded that gamma radiation is less suitable than electron-beam to maintain the characteristics of dried herbs during extended storage periods.

2018Journal article

Open access