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- Antimicrobial and wound healing effects associated to cytocompatibility and the relationship with phytochemical profile of selected Portuguese monofloral honeysPublication . Machado, Alexandra M.; Marto, Joana; Gonçalves, Lídia Maria; Ribeiro, Helena Margarida; Duarte, Aida; Tomás, Andreia; Falcão, Soraia; Vilas-Boas, Miguel; Miguel, Maria Graça; Figueiredo, Ana CristinaOwing to its applications in both food and pharmaceutical industries honey is regarded as a functional product. This study evaluated 32 Portuguese monofloral honeys and their activity was compared with manuka honey 850 + . The antimicrobial activity was determined against Gram-positive and negative bacteria, and yeast. Antioxidant activity, wound healing ability, and cell viability were studied in the human keratinocyte cell line (HaCaT). Phytochemical profile analysis was performed by UPLC/DAD/ESI-MSn. Chestnut, bell heather, eucalyptus, manuka, and strawberry tree honeys demonstrated higher antioxidant activity and were effective against S. aureus. Incense and orange honeys showed wound healing rates of 89 % and 86 %, respectively. All the honeys had cell viability above 76 %. Bell heather and strawberry tree honeys showed the highest total phenolic content, while incense and orange honeys, showed the lower ones. Phytochemical profile analysis evidenced two main clusters, one dominated by isoprenoids and norisoprenoids, as well as phenolic acids and derivatives, while the other included flavonoids as main compounds. Blending different Portuguese monofloral honeys may be an alternative to faster wound healing, by combining their diverse bioactive components. The gathered knowledge can be further explored in formulations that consider the biological activity capacity and composition of each honey.
- Mixture of bee bread with honey: nutritional and microbiological characterizationPublication . Fortes, Adriana; Tomás, Andreia; Rodrigues, Paula; Vilas-Boas, Miguel; Martins, Vitor Manuel RamalheiraBeebread is a hive product produced in the honeycomb, through the lactic fermentation of pollen collected and partially processed by bees. This hive product has a chemical composition that makes it an interesting product, not only because of its nutritional value, but also related with its biological properties, such as antiinflammatory, anticancer, antinociceptive, and antidiabetic. In fact, beebread has earned some attention from the scientific community, being reported as a functional food with nutritional benefits, healing and preventive effects of some diseases.
- Production of chitosan-based biodegradable active films using bio-waste enriched with polyphenol propolis extract envisaging food packaging applicationsPublication . Carli, Cristiane de; Aylanc, Volkan; Mouffok, Kheira; Santamaria-Echart, Arantzazu; Barreiro, M.F.; Tomás, Andreia; Pereira, Celeide; Rodrigues, Paula; Vilas-Boas, Miguel; Falcão, SoraiaDeveloping biodegradable active films has been a promising green approach to overcoming global concerns over the environmental pollution and human health caused by plastic utilization. This study aimed to develop active films based on chitosan (CS), produced from waste crayfish (Procambarus clarkii) shells enriched with bioactive extract (5–20%) of propolis (PS) and to characterize its properties, envisaging food packaging applications. The chromatographic profile of PS extract confirmed its richness, with 41 phenolic compounds. With increasing extract addition to the chitosan, the thickness of the films increased from 61.7 to 71.7 μm, causing a reduction in the light transmission rate, along with a greenish colour shift. The interactions between PS extract and CS was confirmed by infrared spectroscopy, at the same time that the microstructural integrity of the films was checked on the scanning electron microscopy micrographs. The findings also showed that addition of PS enhanced the films thermal stability and mechanical properties e.g., tensile modulus, yield strength, and stress at break. Besides, it improved the antioxidant and antimicrobial activities. Overall, CS-based composite films seem a promising green alternative to petroleum-based synthetic plastics allowing to extend the shelf life of food products due to their eco-friendly nature.
- Stability evaluation of a bee bread and honey mixturePublication . Fortes, Adriana; Tomás, Andreia; Vilas-Boas, Miguel; Rodrigues, Paula; Martins, Vitor Manuel RamalheiraBee bread is a bee product prepared in honeycombs by fermenting bee pollen collected and partially processed by bees. The interest in bee bread is justified by the fact that it is a nutritionally rich food with potential biological activity, often being classified as a functional food. However, due to the difficulty normally associated with its production, beekeepers have not properly valued bee bread.
- Composição e caracterização do mel de urze (Erica app.) portuguêsPublication . Caveiro, Elsa; Falcão, Soraia; Tomás, Andreia; Martins, Vitor Manuel Ramalheira; Vilas-Boas, MiguelO mel de urze (Erica spp.), é um produto apícola que possui alto valor nutricional, antimicrobiano e antioxidante. Este trabalho teve como objetivo a caracterização de 12 amostras de mel de urze (Erica spp.) português proveniente de sete áreas geográficas de Portugal, através da avaliação dos seus parâmetros de qualidade.
- Nutritional value and antioxidant activity of bee pollen submitted to different preservation techniquesPublication . Lema, Filipe; Tomás, Andreia; Vilas-Boas, Miguel; Martins, Vitor Manuel RamalheiraThe moisture content in bee pollen is one parameter of greatest interest for the preservation and quality of this product, since bee pollen is subject to the proliferation of microbiological contaminations that can make its consumption and commercialization unfeasible [1]. Various studies have stated that the choice of preservation technique can have an impact on the chemical composition and antioxidant activity of pollen [2,3,4,5]. Thus, this work intends to evaluate the immediate impact, and also over a storage period of 9 months, of the application of several preservation techniques in the chemical composition and antioxidant activity of the pollen. The bee pollen was collected in Bragança region and frozen at -18ºC, being subsequently preserved through lyophilization or drying in an oven at 35ºC, 40ºC or 45ºC. The chemical composition (moisture content, ash, fat, protein, fructose, glucose and total phenolic compounds) and antioxidant activity (DPPH and reducing power) were analysed immediately after the application of the preservation technique and after 1, 3, 6, and 9 months of storage. In addition to the expected reduction in moisture content, other chemical parameters were significantly affected during the storage period. In general, considering the maintenance of the nutritional value of the pollen, lyophilization was shown to be the most appropriate preservation technique. However, the use of lyophilization appears to have a more evident negative impact on the content of total phenolic compounds and on the antioxidant activity of the pollen, when compared with the oven drying technique, performed at a temperature of 45°C.
- Potentialities of beebread as a food supplement and source of nutraceuticals: botanical origin, nutritional composition and antioxidant activityPublication . Tomás, Andreia; Falcão, Soraia; Russo-Almeida, Paulo; Vilas-Boas, MiguelBeebread is a honey bee product resulting from the storage and lactic fermentation of pollen within the hive. The potential use of beebread as a food supplement and nutraceutical greatly depends on its chemical richness, which varies upon the flora diversity of the region and the season of pollen collection by the bees. To evaluate the potential of this bee product as a food supplement and source of nutraceuticals, we analyzed beebread produced in the northeast region of Portugal, along with a commercial sample. The analysis focused on pollen composition, nutritional parameters (moisture, ash, fats, proteins and sugars), the presence of vitamin E, the phenolic content, and its antioxidant activity. Beebread proved to be a good source of nutrients, with high protein and carbohydrate content, where fructose and glucose were the main sugars resembling the honey sugar profile. Its nutritional value, together with the richness in phenolics and its high bioactivity, makes this product an excellent choice to be consumed as nutraceutical in food supplementation.
- Assessment of bioactive compounds under simulated gastrointestinal digestion of bee pollen and bee bread: Bioaccessibility and antioxidant activityPublication . Aylanc, Volkan; Tomás, Andreia; Russo-Almeida, Paulo; Falcão, Soraia; Vilas-Boas, MiguelBee pollen and bee bread have always been regarded as excellent natural resources for application in food and pharmaceutical fields due to their rich nutrient content and diversity of bioactive compounds with health-improving properties. Extensive studies on both bee products as ingredients for a healthy diet were reported, although the data concerning their metabolization on the gastrointestinal tract is quite limited. Here, we report, at each digestive stage, the bioactive profile for both bee products, their bioaccessibility levels and the antioxidant activity evaluation. The findings indicated that the average bioaccessibility level of total phenolic and total flavonoid content for bee pollen was 31% and 25%, respectively, while it was 38% and 35% for bee bread. This was reflected in a decrease of their antioxidant capacity at the end of in vitro gastrointestinal digestion, both in free radicals scavenging capacity and in reducing power. Moreover, within the 35 phytochemicals identified, the most affected by gastrointestinal digestion were phenylamides, with a complete digestibility at the end of the intestinal phase. Overall, our results highlight that bioactive compounds in both raw products do not reflect the real amount absorbed in the intestine, being bee bread more accessible in bioactive content than bee pollen.
- Phenolic quantification and botanical origin of Portuguese propolisPublication . Falcão, Soraia; Tomás, Andreia; Vale, Nuno; Gomes, Paula; Freire, Cristina; Vilas-Boas, MiguelThe production of propolis by honeybees results from a selective collection of exudates from leaf buds and plants present in the hive neighborhood leading to a resin with many potentialities in the pharmaceutical industry. This study aims to quantify the phenolic content in propolis from different Portuguese regions and in the potential floral sources, Populus x Canadensis Moench buds and Cistus ladanifer L., in order to establish links with geographical and botanical origin. The Portuguese propolis revealed a phenolic profile with marked differences in concentrations: the richness in flavonoids is common in all regions, but more evident in propolis from central interior, south and Madeira. The composition of poplar type propolis common in temperate zones was observed in the north, central coast and Azores, while the central interior and south samples, with a composition rich in kaempferol derivatives, resemble the C. ladanifer exudates, a spontaneous bush widespread in the Mediterranean. The compound kaempferol-3,7-dimethyl-ether, absent in the poplar type propolis, can be regard as a possible marker for the discrimination of these two types of propolis. (C) 2013 Elsevier B.V. All rights reserved.
- Composição fenólica e citotoxicidade de amostras de pão de abelha obtidas no Nordeste de PortugalPublication . Sobral, Filipa; Barros, Lillian; Calhelha, Ricardo C.; Tomás, Andreia; Dueñas, Montserrat; Santos-Buelga, Celestino; Vilas-Boas, Miguel; Ferreira, Isabel C.F.R.O pão de abelha (PA) é uma mistura fermentada de pólen das plantas, mel e saliva das abelhas. As abelhas obreira usam o PA como alimento para as larvas e para que as abelhas jovens produzam geleia real. No presente trabalho, foram estudadas cinco amostras de PA recolhidas em colmeias de Apis mellifera iberiensis em diferentes apiários de Bragança, e uma amostra de PA comercial. Todas as amostras foram caracterizadas por HPLC-DAD-ESI/MS em termos de compostos fenólicos e testandose a sua citotoxicidade em diferentes linhas celulares tumorais humanas (HeLa, MCF-7, HepG2 e NCI-H460), bem como numa cultura primária de células de fígado de porco não tumorais (PLP2). Os principais compostos fenólicos encontrados foram derivados de flavonoides, principalmente quercetina, canferol, miricetina, isoramnetina e herbacetrina. No total, foram identificados trinta e dois compostos nas seis amostras de PA, apresentando as amostras PA1 e PA3 o teor mais elevado e uma maior diversidade de compostos identificados. No entanto, não foi possível estabelecer uma correlação ente os flavonoides presentes nas amostras estudadas e a sua baixa a moderada citotoxicidade. Pelo que percebemos da literatura, este é o primeiro trabalho de caracterização exaustiva dos flavonoides glucosilados em amostras de PA, contribuindo assim para a caracterização química deste produto apícola ainda pouco explorado.