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Revalorization of spent coffee residues by a direct agronomic approach

Publication . Cruz, Rebeca; Mendes, Eulália; Torrinha, Álvaro; Morais, Simone; Pereira, J.A.; Baptista, Paula; Casal, Susana

Spent coffee grounds (SCG) represent a high-volume food waste worldwide, and several reuse approaches have been attempted. Herein, a greenhouse field experiment was carried out by cultivating Batavia lettuce with 5%, 10%, 15%, 20% and 30% (v/v) espresso SCG directly composted in the soil. Healthy vegetables were obtained for all treatments, without yield loss for up to 10% SCG. A progressive increment of green color intensitywith increasing SCG content was observed, corroborated by the increase of their photosynthetic pigments (chlorophylls and carotenoids). Furthermore, total ascorbic acid and tocopherols showed statistical significant increases (p b 0.001) between control and all tested groups.Marked variations of nutritionally relevant minerals, particularly potassium, phosphorous and sodiumwere also revealed at higher percentage treatments (20% and 30%). This approach constitutes a clean, direct, simple and cost-effective measure to produce value-added vegetables, while reducing food waste disposal.

2015Journal article

Restricted access

Autenticação de produtos cárneos com a designação Halal: Deteção e quantificação de derivados de suíno (Sus scrofa)

Publication . Amaral, Joana S.; Costa, Joana; Mafra, Isabel; Oliveira, Beatriz

Devido aos recentes escândalos alimentares relacionados com adulterações em produtos cárneos, tem-se assistido a uma maior atenção por parte dos consumidores e autorida-des sobre a ocorrência de fraudes neste setor, especialmen-te no que respeita a substituição de carne de espécies ani-mais de valor elevado por proteínas musculares de mais baixo custo. Em particular, devido ao seu baixo preço e ele-vada disponibilidade, a carne de porco e/ou derivados de suíno (gordura, plasma, colagénio, entre outros) podem ser fraudulentamente adicionados em produtos cárneos, tendo por objetivo o aumento de lucros de fabricantes pouco es-crupulosos [1,2]. Para além destas práticas representarem uma fraude económica, a presença de espécies animais não declaradas na rotulagem é algo que causa elevada preocu-pação em certos grupos religiosos para os quais o consumo de determinadas espécies é proibido.

2015Journal article

Open access

Safety concerns regarding plant food supplements

Publication . Rocha, Tiago; Amaral, Joana S.; Oliveira, Beatriz

In the last years, plant food supplements (PFS) consumption has been increasing in developed countries, in part reflecting the growing acceptance and use of alternative/traditional medicine but also due to the common idea that PFS are natural products posing no risks to human health. Being legally considered as foods under Directive 2002/46/EC, PFS are under control of the European Food Safety Agency (EFSA) and do not require the same requisites as traditional herbal medicines for legal authorization In practice, this means that several products are being sold under the umbrella of PSF, being easily avaiJable in supermarkets, .TV shops and the internet, and not under the supervision and control of the' health authorities.

2014Conference object

Open access

Detection of botanical adulterations in plant food supplements by molecular biology techniques

Publication . Amaral, Joana S.; Costa, Joana; Fernandes, Telmo J.R.; Batista, Andreia; Oliveira, Beatriz; Mafra, Isabel

In the last years, botanicals have become increasingly available in the EU market in the form of plant food supplements (PFS), which are legally considered as foods under Directive 2002/46/EC and consequently not submitted to safety assessment prior to commercialisation. A concern related with PFS regards its botanical composition since unintentional swap of plants has been reported and also because adulterations by the substitution of higher cost botanicals for closely related, but cheaper species, can occur. Thus, there is a need for reliable methodologies to authenticate botanicals in commercialised PFS. Recently, molecular biology techniques have been suggested for this purpose. However, difficulties in recovering DNA from some PFS samples have been described (1). Thus, as part of a study for the botanical authentication of PFS, this work aimed at assessing the interference of pharmaceutical excipients on the recovery/amplification of DNA. Different PFS (tablets and capsules) were submitted to DNA extraction and amplified by real-time polymerase chain reaction (PCR) targeting universal eukaryotic and plant genes using species-specific primers for Hypericum DNA barcode loci. However, some samples gave consistently negative PCR amplifications irrespective of the target gene or DNA extraction method used, raising the question of whether some excipients could interfere with DNA extraction from PFS. To address this question, model mixtures of pharmaceutical excipients and water as control, were spiked with known amounts of template maize DNA. Each mixture was then submitted to DNA extraction and maize DNA quantified by real-time PCR. The use of either 10% talc or 0.5 % dyes (iron oxide or titanium dioxide) completely adsorbed DNA, resulting in negative PCR amplifications. The use of 1% talc or 10% silica, both frequently used as diluents in PFS, allowed recovering very low amounts of maize DNA (7.1 % and 2.5%, respectively). The results showed a clear adsorption phenomena that justify the hampering effect on DNA extraction from PFS explaining the inability of recovering DNA from some samples reported in previous works. Thus, a strategy to release plant DNA from excipients, allowing its extraction and further analysis was also assayed. Hypericum species were not detected in four PFS, although being described on the label.

2015Conference object

Open access

Effect of Drying on Color, Proximate Composition and Drying Kinetics of Sliced Chestnuts

Publication . Delgado, Teresa; Pereira, J.A.; Casal, Susana; Ramalhosa, Elsa

In the present work, dried sliced chestnuts (Judia and Longal varieties), product with an increased shelf life, low calorie and gluten-free contents, were prepared. The effect of air convective drying on the drying kinetics, color and proximate composition of sliced chestnuts was evaluated. Even though significant differences in nutritional composition were found between both varieties at the beginning, the drying behaviors were similar; however, Judia dried at a slightly faster rate than Longal. The use of Page, two-term, and modified Henderson and Pabis models fitted well the experimental data (adjusted R 2 > 0.999). With drying, slight variations in color were observed for both varieties and only moisture content decreased significantly. The obtained product retained all chemical composition, and due to the low caloric value (367 kcal/100 g product), low fat and gluten-free contents of chestnut slices, this can be an interesting substitute to other high-calorie snacks available in the market. Practical Applications: The chestnut fruit is increasingly popular among consumers. The fruit is usually sold fresh or frozen while smaller fruits are generally rejected by industries. So, it is very important to find alternatives to valorize these fruits. Moreover, consumers search for healthy and easy-to-consume food. Chestnut follow these requisites, being a nut with interesting properties due to its low fat content, high levels of starch (sugar of slow absorption) and significant amounts of fibers. Furthermore, it is a gluten-free nut, ideal for celiac patients. On the other hand, the majority of snacks in the market are rich in fat and are made from wheat flour. So, the development of snacks based on chestnut would be innovative. This study intends to provide information on the effect of drying on color, nutritional composition and drying kinetics of sliced chestnut in order to obtain a healthy and low-calorie content snack.

2016Journal article

Open access