A amora silvestre é um fruto com um alto conteúdo de nutrientes essenciais e de fitoquímicos que têm uma importância relevante na saúde humana. Pretendemos verificar o valor nutricional e avaliar as características físico-químicas e organoléticas de quatro espécies de amora de silva (Rubus brigantinus, Rubus henriquesii, Rubus radula, Rubus sampaioanus) ainda não comercializadas de modo a avaliar a sua qualidade para uma futura aceitação no mercado. Os frutos apresentaram valores de humidade entre 84,9 e 87,9%; proteína entre 1,2 e 1,4%, gordura entre 0,3 e 0,7%, cinzas entre 0,4 e 0,7% e glúcidos entre 9,9 e 12,4%. Os Sólidos solúveis, determinados no ano 2011, variaram entre 10,4 a 13,8º Brix e a acidez variou entre 4,4e 10,2%. No ano 2012, os sólidos solúveis variaram entre 11,1 a 14,1º Brix e a acidez variou entre 11,5 e 13,7%. Os parâmetros de cor medidos com o colorímetro são concordantes com a análise sensorial, indicam espécies com frutos escuros, de cor indefinida e com um brilho pouco intenso. A espécie Rubus brigantinus apresentou características mais próximas daquelas a que os elementos do painel estão habituados a percecionar nas amoras, pois foi nitidamente a espécie que mais agradou ao painel. Foi também a que em 2012 apresentou um maior teor de sólidos solúveis e a menor acidez e por consequência a razão “açúcar/ácidos” mais elevada o que indica um sabor mais doce, geralmente preferido pelos consumidores.

Short-term 48 h laboratory bioassays with water from an acid mine drainage (AMD: pH 3.3, 4.4, 5.0, 5.5, 6.4, control) and water from an arsenic containing reservoir were performed with the freshwater shrimp Atyaephyra desmaresti Millet, validated in situ and compared to acidified control water (ACID). Behaviour, mortality and time to death were monitored with the Multispecies Freshwater Biomonitor (MFB). The shrimps had equal 24 h-LC(50)s at pH 4 in AMD and ACID. However, after 48 h AMD proved more toxic (48 h-LC50 at pH 5.2) than ACID (48 h-LC50 at pH 4.5). Stress behaviour in AMD consisted at pH <= 6.4 of a pH-dependent decrease in activity, with disappearance of circadian rhythmicity, and at pH 4.4 a clear increase of ventilation. At pH 5.5 bioaccumulation of metals was higher and locomotion lower than at pH 5.0. In ACID, only at pH <= 4.4 locomotion became abated and arythmic. Locomotion in the field was equal or higher compared to the laboratory, whereas the ventilation was higher in the laboratory. A. desmaresti is a valuable species to be used in short term behavioural bioassays of AMD in Europe.

An integrated multilevel phytoassessment of an acid mine drainage (AMD, pH range 3.3-6.8) in southern Portugal was performed. A 7-day phytotoxicity bioassay with the duckweed Lemna gibba (chlorosis, necrosis, growth) was carried out, both in the laboratory and in situ, combined with an analysis of the resident epilithic diatom community. The toxicity test was performed with water from the AMD gradient, an unpolluted river control and acidified control water, in order to discriminate potential pH-effects from combined pH- and metal-effects. Diatom communities discriminated well among the sites (alkalophilic species versus halobiontic, acidobiontic and acidophilic species), showing inter-site differences to be larger than intra-site seasonal variations. In L. gibba exposed to AMD, necrosis and growth inhibition were higher in situ compared to the laboratory experiments. L. gibba was more sensitive to AMD than to acidified water. Already after 4 days, growth rate inhibition in L. gibba proved to be a reliable indicator of AMD-stress. Ecotoxicological thresholds obtained with L. gibba corresponded with those obtained previously with animals of intermediate tolerance to AMD. The results were summarised in a multimetric index.

The pH control during winemaking is a fundamental parameter by their influence on color, freshness and to achieve wine microbiological stability. The most common acidify correction performed in wineries is addition of natural tartaric acid; however, in some cases, this operation increases the risks of potassium bitartrate precipitations [1, 2]. The application of ion exchange resins for wine acidification is based on ability of exchanging ions fixed on functional groups, namely by exchanging cations, such as potassium, with hydrogen ions. Nevertheless, there is an important lack of knowledge on the impact of this operation on wine sensory characteristics. To adjust wine pH, a certain amount of treated wine by ion exchange resins is mixed with the untreated wine [3]. According to OIV [4], treatment must not lower the pH of wine below 3.0 and the decrease should not exceed 0.3 pH units. Anion exchangers are not allowed by the OIV [3] due to the negative effects on the wine sensory quality [5,6]. Therefore, the aim of this work was to evaluate the effect of cation exchange resins, authorized by the OIV, according to Resolution 43/2000 [3] on wine pH control and to evaluate their impact on wine sensory quality at industrial scale. In this study a white and a red wine from the Douro Valley region, 2015 vintage, was used. In this work ion exchange resin treated white wine was almost 20% from total white wine volume and red wine was almost 30% from total red wine volume. The present study indicated that there were no considerable changes in sensory attributes, although a slight improvement in the aroma and taste, as a result of the ion-exchange pH adjustment. These results show that the application of ion exchange resins process to wine could be an interesting tool for white and red wine pH adjustment, without interfering with wine sensorial quality.

The pH control during winemaking is a fundamental parameter by their influence on color, freshness and to achieve wine microbiological stability. The most common acidify correction performed in wineries is addition of natural tartaric acid; however, in some cases, this operation increases the risks of potassium bitartrate precipitations [1, 2]. The application of ion exchange resins for wine acidification is based on ability of exchanging ions fixed on functional groups, namely by exchanging cations, such as potassium, with hydrogen ions. Nevertheless, there is an important lack of knowledge on the impact of this operation on wine sensory characteristics. To adjust wine pH, a certain amount of treated wine by ion exchange resins is mixed with the untreated wine [3]. According to OIV [4], treatment must not lower the pH of wine below 3.0 and the decrease should not exceed 0.3 pH units. Anion exchangers are not allowed by the OIV [3] due to the negative effects on the wine sensory quality [5,6]. Therefore, the aim of this work was to evaluate the effect of cation exchange resins, authorized by the OIV, according to Resolution 43/2000 [3] on wine pH control and to evaluate their impact on wine sensory quality at industrial scale. In this study a white and a red wine from the Douro Valley region, 2015 vintage, was used. In this work ion exchange resin treated white wine was almost 20% from total white wine volume and red wine was almost 30% from total red wine volume. The present study indicated that there were no considerable changes in sensory attributes, although a slight improvement in the aroma and taste, as a result of the ion-exchange pH adjustment. These results show that the application of ion exchange resins process to wine could be an interesting tool for white and red wine pH adjustment, without interfering with wine sensorial quality.

The increase of soluble solids in milk by the addition of powdered products is a normal practice in the elaboration of yogurt in order to enhance viscosity, texture and sensory properties for the consumer. The purpose of this study was to evaluate the effect of adding jumbo squid (Dosidicus gigas) powder (protein content, 420 g/kg) on the aforementioned quality properties of yogurt. Six formulations of yogurt were prepared with the addition of 0, 1, 3, 5, 7 or 10 g/100 mL jumbo squid powder, plus one formulation with 3 g/100 mL maltodextrin. During fermentation, yogurts formulated with squid powder gradually achieved greater viscosity while producing both more acidity and at a higher rate than the controls. Apart from lower pH (hence, higher titratable acidity) and higher viscosity, the final enriched yogurts presented lower syneresis than the controls (p < 0.05). Although the highest viscosity (58.90 Pa.s) and the lowest syneresis (1.00%) was achieved by the yogurt with 10 g/100 mL jumbo squid powder, it was the treatment formulated with 3 g/100 mL (pH 4.31, acidity 0.85 g/100 g, viscosity 40.90 Pa.s and syneresis 9.10%) that kept constant sensory properties, as evaluated by the panelists, while improving some physical properties of the control yogurts.

A portable potentiometric electronic tongue (PE-tongue) was developed and applied to evaluate the quality of milk with different fat content (skimmed, semi-skimmed, and whole) and with different nutritional content (classic, calcium-enriched, lactose-free, folic acid-enriched, and enriched in sterols of vegetal origin). The system consisted of a simplified array of five sensors based on PVC membranes, coupled to a data logger. The five sensors were selected from a larger set of 20 sensors by applying the genetic algorithm (GA) to the responses to compounds usually found in milk including salts (KCl, CaCl2, and NaCl), sugars (lactose, glucose, and galactose), and organic acids (citric acid and lactic acid). Principal component analysis (PCA) and support vector machine (SVM) results indicated that the PE-tongue consisting of a five-electrode array could successfully discriminate and classify milk samples according to their nutritional content. The PE-tongue provided similar discrimination capability to that of a more complex system formed by a 20-sensor array. SVM regression models were used to predict the physicochemical parameters classically used in milk quality control (acidity, density, %proteins, %lactose, and %fat). The prediction results were excellent and similar to those obtained with a much more complex array consisting of 20 sensors. Moreover, the SVM method confirmed that spoilage of unsealed milk could be correctly identified with the simplified system and the increase in acidity could be accurately predicted. The results obtained demonstrate the possibility of using the simplified PE-tongue to predict milk quality and provide information on the chemical composition of milk using a simple and portable system.

A bentonite collected at Serra de Dentro (SD), Porto Santo Island, Portugal, and the source clay SAz-1 (Cheto, Arizona) were ion-exchanged with different cations (Al3+, Ni2+, Cr3+ and Na+ ). Variable temperature diffuse reflectance infrared Fourier transform spectroscopy (VT-DRIFTS) of pyridine treated samples, thermal desorption of cyclohexylamine and real time mass spectrometry of the evolved gases were used to evaluate the acidic properties of the prepared catalysts. The catalytic activity of these ion-exchanged clays was tested in the acid-catalysed conversion of limonene at 150 8C, to yield isomerization products (terpinolene, a-terpinene, g-terpinene and isoterpinolene), disproportionation products ( p cymene and p-menthenes) and high molecular-weight compounds. The possibility of increasing the selectivity toward p-cymene, over a catalyst with substantial Lewis acid character, was particularly envisaged. Catalysts derived from SD were significantly more active than their SAz-1 counterparts. This was mainly attributed to the greater inherent acidity, to the higher structural iron content (providing dehydrogenation activity) and to the higher nitrogen surface area of the starting SD clays. Within the Mn+ -SD series, the order of activity decreased as Ni2+ > Al3+ > Cr3+ > Na+ . A direct comparison between Al3+-SD (with maximized Bro¨nsted acidity) and Ni2+-SD (with predominant Lewis acid character) provided no support for enhanced p-cymene production over Lewis acid sites.

A series of acid-activated clay catalysts were prepared from a purified bentonite, rich in structural iron, collected at Serra de Dentro on the island of Porto Santo. The purified bentonite exhibited a surface area of 130 m2 g 1 which increased to values as high as 500 m2 g 1 following activation with 4M HCl at 95 8C for 30 min (SD-4M-95-30). The ability of the activated samples to convert limonene to p-cymene was evaluated using a reaction time of 15 min at 80 8C. The sample prepared using 3M HCl at 95 8C for 30 min (SD-3M-95-30) offered the optimum combination of surface area (470 m2 g 1 ) and acidity (0.26 mmol g 1 ) and 95% of the limonene was converted to product. About 15% of the product mixture was p-cymene whilst non-volatile products and polymeric species made up 54% of the product mixture. The presence of iron in the octahedral sheet of the SD bentonite appears responsible for the dehydrogenation activity. TG–MS analysis of acid activated samples, saturated with cyclohexylamine, reflected the dehydrogenation capabilities of the catalysts in that SD-3M-95-30 produced the most benzene and aniline as decomposition/ transformation products.

A presente investigação visa avaliar o efeito de intervenções de engenharia para a reabilitação de sítios mineiros sobre sistemas fluviais recetores de drenagem ácida. Estabelecendo a mina de Valdarcas como caso de estudo, a metodologia de trabalho consistiu em definir um plano de monitorização de modo a avaliar as propriedades gerais do efluente ao longo do tempo e o grau de cobertura vegetal das escombreiras. As propriedades do efluente evidenciam o efeito da paragénese do jazigo, revelando caraterísticas ácidas e indicando a sua proveniência a partir da dissolução de sulfuretos, principalmente sulfuretos de ferro. O efluente é conduzido por um sistema de tratamento simples de tipo passivo, implementado entre 2005 e 2007, através de obras de reabilitação ambiental efetuadas na área. Como tal, pretende-se observar a eficiência de processos de atenuação natural que decorram no sistema em estudo. Com base em dados obtidos em trabalhos anteriores foi possível avaliar a evolução temporal do sistema num período longo, que decorreu entre 2003 e 2015. Os resultados mostram que o efluente sofre grandes variações nos seus parâmetros ao longo do tempo. Contudo, apesar de ainda se verificar elevada acidez e sulfato, a análise dos resultados demonstra um decréscimo, não só destes valores, mas também dos teores de metais após a intervenção de reabilitação. A ocorrência de fenómenos de atenuação natural contribui para limitar os efeitos ambientais negativos desta drenagem. As escombreiras de Valdarcas, principal foco de contaminação aquática, mas também fonte de degradação paisagística, foram igualmente sujeitas a monitorização, revelando sucesso do processo de revegetação, caracterizado pela presença geral de espécies autóctones, tanto arbustivas como arbóreas. Este estudo lembra a utilidade de uma monitorização assídua após intervenção de reabilitação ambiental em áreas mineiras abandonadas, de modo a construir um núcleo de informação capaz de transmitir as dificuldades dos sistemas e permitir eleger ou melhorar o método de tratamento a ser implementado.