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- Temperature Effect on Rheological Behavior of Portuguese HoneysPublication . Afonso, Maria João A.P.S.; Magalhães, Marta; Fernandes, Luana; Castro, Marina; Ramalhosa, ElsaIn the present work the temperature effect on rheological properties of Portuguese honeys was studied for the fi rst time. Two unifl oral honeys – heather and rosemary – and a polyfl ower honey were analyzed. All honeys showed fl ow independence over time and behaved as Newtonian fl uids at the studied temperature and shear rate ranges. For all honeys it was found that the viscosity decreased with temperature and the rosemary honey was the one that always presented the lowest viscosity at 30°C (6120 mPa·s), 50°C (603 mPa·s) and 70°C (145 mPa·s). The temperature dependence of viscosity was well described by the T B A K e 0 equation. Nevertheless, good regression coeffi cients were also obtained when fi tting the experimental data to the Arrhenius model, showing the rosemary honey to be less temperature sensitive. The results obtained in this study are of great interest to beekeepers and industrials that handle and prepare eatable honey-based products because they will be better informed about the best type of honey to use.
- Sensory analysis of pansies subjected to different post-harvest technologies: high hydrostatic pressure, alginate coating and crystallisationPublication . Fernandes, Luana; Casal, Susana; Pereira, J.A.; Saraiva, Jorge A.; Ramalhosa, ElsaThe present study aimed to investigate consumers’ knowledge about edible flowers and post-harvest technologies through an online survey. Simultaneously, the effects of some post-harvest technologies (high hydrostatic pressure (HHP), alginate coating and crystallisation) on sensory characteristics of pansies were evaluated in loco by chefs and consumers. Most of the participants recognised edible flowers as a food component and had a favourable opinion about them. 79% were willing to pay more to acquire a product with a longer shelf-life. The sensory profiles of chefs and consumers were different; however, the scores for HHP were similar, except for the overall acceptance (p=0.025). The chefs rated the HHP pansies with the highest scores for visual appearance (p=0.015), texture (p=0.032) and overall acceptance (p=0.001). The consumers did not find significant differences in overall acceptance between treatments. So, this work gives important information about the consumers’ opinion of edible flowers that can help the producers.
- Effect of high hydrostatic pressure on the quality of four edible flowers: Viola × wittrockiana, Centaurea cyanus, Borago officinalis and Camellia japonicaPublication . Fernandes, Luana; Casal, Susana; Pereira, J.A.; Pereira, Ermelinda; Ramalhosa, Elsa; Saraiva, Jorge A.The aim of the study was to evaluate the effect of high hydrostatic pressure (HHP) on the appearance, bioactivity and microbial content of four edible flowers along storage. Several treatments at 75–450 MPa and holding times (1, 5 and 10 min) were applied. Borage and camellia were unacceptable after all treatments, while centaurea showed good appearance at 100/5 MPa min -1 ; however, the shelf life did not increase. Pansies treated at 75/5 and 75/10 MPa min -1 also retained the appearance of fresh flowers. Furthermore, pansies submitted at 75/5 MPa min -1 maintained good appearance over 20 days of storage at 4 °C, while the untreated remained satisfactory only until 6 days. Even though no significant differences on microbial load were observed between untreated and HHP-treated pansies in day 0, HHP induced the production of bioactive compounds, increasing the shelf life of pansies. So, the HHP treatment is a promising technology for Viola × wittrockiana.
- Do jardim à mesaPublication . Fernandes, Luana; Saraiva, Jorge A.; Pereira, J.A.; Casal, Susana; Ramalhosa, ElsaDesde há muito que as flores são usadas na alimentação em diversos locais do mundo. Nos últimos anos, este segmento tem mostrado uma procura e utilização crescentes,nomeadamente em Portugal. No nosso País, em 2012, existiam 1 010 explorações a produzir culturas florícolas, numa área base de 1 365 ha, abrangendo três tipos de produção: flores de corte, folhagens de corte e complementos de flores (e.g. feto e asparagus), e plantas ornamentais (INE, 2013), não existindo, contudo, dados específicos para as flores comestíveis. No presente trabalho descrevem-se algumas flores comestíveis utilizadas na culinária, bem como alguns cuidados a ter na colheita, no processamento e armazenamento das mesmas.
- Borage, camellia, centaurea and pansies: Nutritional, fatty acids, free sugars, vitamin E, carotenoids and organic acids characterizationPublication . Fernandes, Luana; Ramalhosa, Elsa; Pereira, J.A.; Saraiva, Jorge A.; Casal, SusanaThe present study aimed to evaluate the nutritional and bioactive potential of four edible flowers (borage, centaurea, camellia, and pansies). Significant differences were observed among the four. Water was the main constituent (> 76%, fresh weight - fw). Linoleic and palmitic acids were the major fatty acids found in borage and red and yellow pansies, while in camellia it was the arachidic acid. In white pansies, behenic and arachidic acids were predominant. Concerning vitamin E, α-tocopherol was the major vitamer. Carotenoids values varied between 5.8 and 181.4 mg β-carotene/100 g dry weight (dw) in centaurea and borage, respectively, being particularly rich in lutein. Malic acid was the major organic acid, except in centaurea, where succinic acid was predominant. Fructose, glucose and sucrose were detected in all flowers. These results can contribute to the knowledge of these edible flowers and consequently increase their popularity among consumers and in the food industry.
- Effect of application of edible coating and packaging on the quality of pansies (Viola × wittrockiana) of different colors and sizesPublication . Fernandes, Luana; Pereira, J.A.; Baptista, Paula; Saraiva, Jorge A.; Ramalhosa, Elsa; Casal, SusanaThe effects of alginate edible coating on the quality of pansies (visual appearance, weight loss, water activity, color, and dimensions change) were studied during refrigerated storage (4 C). The role of pansies’ color and size, as well as packaging, was also studied. Alginate treatments resulted in a beneficial effect on the visual appearance of pansies under refrigerated storage when compared to the uncoated, delaying their degradation from 3–4 days up to 14 days, depending on the pansies’ color, probably derived from their different petal thicknesses (83 to 183 mm for yellow and red pansies). The unpackaged coated pansies had different behaviors during storage, associated with their dimensions (the larger coated pansies maintained good visual appearance during longer storage times than the smaller ones). However, the packaged pansies treated with edible coating showed to have lower weight loss and shrinkage than the unpackaged, irrespective of the color and size, with physical stability up to 14 days. In summary, the cumulative use of alginate coating with packaging under refrigerated storage may contribute to extend pansies’ shelf life.
- Efeito da humidade relativa nas propriedades físico-químicas e microbiológicas de miolo de amêndoa ao longo do armazenamentoPublication . Graeff, Francieli; Fernandes, Luana; Pereira, Ermelinda; Pereira, J.A.; Garcia, Carolina; Ramalhosa, ElsaA amêndoa (Prunus dulcis (Miller) Webb) é um fruto consumido em cru ou processado (ex. laminado, granulado, farinha) como ingrediente em diversos produtos de pastelaria, chocolates, entre outros. Ao contrário do fruto com casca que apresenta um tempo de prateleira longo, o miolo é mais suscetível a perder qualidade pela oxidação lipídica e desenvolvimento de bolores que podem pôr em causa a sua segurança. No presente trabalho, pretendeu-se avaliar o efeito da humidade relativa nas características físico-químicas e microbiológicas de miolo de amêndoa, armazenado a 25 °C, de modo a simular condições de armazenamento e de transporte marítimo que possam ocorrer em países tropicais, para os quais a amêndoa Portuguesa é exportada. Para tal, estudaram-se em armazenamento, o efeito de três humidades relativas (HR) (60, 70 e 80%) durante 2 meses, a 25 °C. Ao longo do tempo de armazenamento (0, 1 e 2 meses), avaliou-se a atividade da água, cor, teores de humidade, gordura e proteína, estabilidade oxidativa do fruto e óleo, e parâmetros microbiológicos. Em relação à atividade da água, os menores valores foram observados para a HR de 60%, após 1 (0,624±0,007) e 2 meses (0,595±0,006). Ao contrário das HRs de 60 e 70%, para a de 80% não se observaram diferenças significativas ao longo do tempo de armazenamento. No que respeita aos parâmetros nutricionais, para cada HR ao longo do tempo, não se observaram diferenças significativas. Ao comparar as HRs entre si, as únicas diferenças significativas foram detetadas para o teor de humidade após 1 mês (menores valores para HR=60%) e para a proteína após 2 meses (menores valores para a HR de 70%). Na estabilidade oxidativa, avaliada pelo método Rancimat, verificou-se que os frutos apresentaram maiores tempos de indução do que o óleo, para todas as condições estudadas. Salvo raras exceções, não se observaram diferenças significativas nos tempos de indução, tanto para o fruto como para o óleo, para as três HRs estudadas ao longo do tempo de armazenamento. Em relação à qualidade microbiológica, verificou-se um decréscimo significativo nos microrganismos a 30 °C após 2 meses em relação ao início. Pelo contrário, nos bolores e leveduras não se observaram diferenças significativas ao longo do armazenamento. Em conclusão, as humidades relativas de 60, 70 e 80% não afetaram de forma relevante a qualidade final do miolo de amêndoa.
- Lipid composition of seed oils of nine Spanish pomegranate (Punica granatum L.) cultivarsPublication . Fernandes, Luana; Pereira, J.A.; Lopéz-Cortés, Isabel; Salazar, Domingo M.; Casal, Susana; Ramalhosa, ElsaPomegranate (Punica granatum L.) is an ancient fruit tree traditionally cultivated in the Near and Middle East. Presently, it’s most important growing regions include Afghanistan, Iran, Israel, USA, Italy and Spain, being the last country the largest European exporter. Pomegranate fruit can be divided into several anatomical compartments: outside peel, inside peel, and arils (pulp and seeds), being the last usually used for fresh consumption, juice, jams and jellies production. Even though pomegranate seeds are an industrial byproduct, recent reports have highlighted their potential use as a source of oil with beneficial chemical attributes. In spite of this the main objective of the present work was to characterize the seed oils of nine pomegranate varieties of European origin, collected in Spain, including their fatty acid and vitamin E compositions, to assess their potential to be used as nutraceuticals or functional food ingredients. All seed lipid fraction consisted mainly on punicic acid (c9,t11,c13 C-18:3) (ranging between 77.3% and 83.6% of total fatty acids), followed by small amounts of linoleic acid (C18:2n6), oleic acid (C18:1n9) and palmitic acid (C16:0). Regarding vitamin E composition, α-, γ-, δ-tocopherols were found in all pomegranate seed oils, mainly γ-tocopherol, with total tocopherols ranging from 174.5 to 627.3 mg/100g oil. Conversely, tocotrienols were not detected. In conclusion, these results indicate that pomegranate seed oils are rich in punicic acid, a conjugated linolenic acid with interesting anti-carcinogenic activity, being simultaneously rich in tocopherols, of technological and nutritionally relevance.
- Efeito de três revestimentos comestíveis nas propriedades físico-químicas e qualidade microbiológica de castanhas durante o seu armazenamentoPublication . Ramalhosa, Elsa; Fernandes, Luana; Gomes, Auryo; Batista, Bianca; Barbosa, Larissa; Fidalgo, Maria do Céu; Galvão, Hilton; Pereira, ErmelindaPortugal é um importante produtor de castanha (Castanea sativa Mill.) a nível mundial. No entanto, as castanhas são um fruto muito suscetível ao crescimento microbiano e à desidratação. Os revestimentos comestíveis podem surgir como um novo tratamento para manter a qualidade da castanha durante mais tempo. Com vista a obter mais informação sobre este ponto, o presente trabalho visou avaliar o efeito de três revestimentos (proteína do soro, alginato e quitosano) nas propriedades físico-químicas e microbiológicas de castanhas, armazenadas durante 6 meses sob refrigeração. Os resultados indicaram que em todas as amostras poucas variações ocorreram no teor de humidade, atividade de água e textura ao longo do tempo de armazenamento. Pelo contrário, verificou-se uma diminuição nos valores de a*, b* e C da casca exterior em todas as amostras, e um aumento no valor de L* nas castanhas revestidas com alginato, até 3 meses. Em relação à acidez e ao teor de sólidos solúveis totais, observou-se um aumento para as amostras revestidas e controlo após 6 meses de armazenamento face ao início, bem como na contagem de microrganismos, com uma exceção. Após 6 meses de armazenamento, as amostras revestidas com quitosano foram as que apresentaram as menores contagens de microrganismos a 30 °C (4,30±0,26 log ufc/g) e de bolores e leveduras (5,24±0,11 log ufc/g). Assim, o revestimento de quitosano mostrou ter algum potencial para aumentar o tempo de vida útil da castanha, uma vez que retardou o crescimento microbiano.
- Borage, calendula, cosmos, Johnny Jump up, and pansy flowers: volatiles, bioactive compounds, and sensory perceptionPublication . Fernandes, Luana; Casal, Susana; Pereira, J.A.; Malheiro, Ricardo; Rodrigues, Nuno; Saraiva, Jorge A.; Ramalhosa, ElsaThe aim of the present work was to study the main volatile and bioactive compounds (monomeric anthocyanins, hydrolysable tannins, total flavonoids, and total reducing capacity) of five edible flowers: borage (Borage officinalis), calendula (Calendula arvensis), cosmos (Cosmos bipinnatus), Johnny Jump up (Viola tricolor), and pansies (Violaxwittrockiana), together with their sensory attributes. The sensory analysis (10 panelists) indicated different floral, fruity, and herbal odors and taste. From a total of 117 volatile compounds (SPME-GC-MS), esters were most abundant in borage, sesquiterpenes in calendula, and terpenes in cosmos, Johnny Jump up, and pansies. Some bioactive and volatile compounds influence the sensory perception. For example, the highest content of total monomeric anthocyanins (cosmos and pansies) was associated with the highest scores of colors intensity, while the floral and green fragrances detected in borage may be due to the presence of ethyl octanoate and 1-hexanol. Therefore, the presence of some volatiles and bioactive compounds affects the sensory perception of the flowers.