GeoBioSciences GeoTechnologies and GeoEngineering

Funder

Organizational Unit

Publications

Soil arsenic toxicity impact on the growth and C-Assimilation of Eucalyptus nitens

Publication . Ramalho, José C.; Pelica, João; Lidon, Fernando C.; Silva, Maria M. A.; Simões, Maria M.; Guerra, Mauro; Reboredo, Fernando H.

The selection of adequate plants that can cope with species that can live in contaminated/ degraded and abandoned mining areas is of utmost importance, especially for environmental management and policymakers. In this framework, the use of a fast-growing forestry species, such as Eucalyptus nitens, in the recovery of arsenic (As) from artificially contaminated soils during a longterm experiment was studied. Roots can accumulate to levels ranging between 69.8 and 133 g g􀀀1 for plants treated with 100 and 200 g As mL􀀀1, respectively, while leaves between 9.48 g g􀀀1 (200 As) and 15.9 g g􀀀1 (100 As) without apparent morphological damage and toxicity symptoms. The C-assimilation machinery performance revealed a gradual impact, as evaluated through some gas exchange parameters such as the net photosynthetic rate (Pn), stomatal conductance to H2O (gs), and transpiration rate (E), usually with the greater impacts at the highest As concentration (200 As), although without significantly impacting the PSII performance. The As effects on the uptake and translocation of Ca, Fe, K, and Zn revealed two contrasting interferences. The first one was associated with Zn, where a moderate antagonism was detected, whereas the second one was related to Fe, where a particular enrichment in leaves was noted under both As treatments. Thus, it seems to exist a synergistic action with an impact on the levels of the photosynthetic pigments in As-treated plant leaves, compared with control plants. E. nitens must be considered as an alternative when phytoremediation processes are put into practice in our country, particularly in areas with cool climatic conditions.

2023-04Journal article

Open access

Elemental Composition of Commercial Herbal Tea Plants and Respective Infusions

Publication . Fernandes, Jaime; Reboredo, Fernando H.; Luís, Inês; Silva, Maria Manuela; Simões, Maria M.; Lidon, Fernando C.; Ramalho, José C.

This study evaluated the elemental composition of 25 herbal tea plants commonly used in infusions by Portuguese consumers and the contribution to the elemental daily intake of some essential elements. Hydrocotyle asiatica (L.), Matricaria chamomilla (L.), and Melissa officinalis (L.) samples are a rich source of K with around 6.0 mg g-1 while the Asteraceae Silybum marianum (L.) and Echinacea angustifolia (DC.) exhibited 4.9 and 5.6 mg g-1 Ca, respectively. The highest concentrations of S and Zn were noted in Hydrocotyle asiatica (L.), while the highest concentration of Sr was found in Cassia angustifolia (Vahl.). In general, a large variability in the concentrations among different families and plant organs had been observed, except Cu with levels around 30 g g-1. The principal component analysis (PCA) showed positive correlations between Zn and S and Sr and Ca, also revealing that Hydrocotyle asiatica (L.), Echinacea angustifolia (DC.), Silybum marianum (L.), and Cassia angustifolia (Vahl.) samples, stands out about all other samples regarding the enrichment of macro and micronutrients. The elemental solubility of macronutrients in the infusion is greater than the micronutrient solubility, despite the contribution to the recommended daily intake was weak. As a whole, Cynara scolymus (L.) and Hibiscus sabdariffa (L.) are the species with the best elemental solubilities, followed by Hydrocotyle asiatica (L.). No harmful elements, such as As and Pb, were observed in both the raw material and the infusions

2022Journal article

Open access

Influence of air-drying conditions on quality, bioactive composition and sensorial attributes of sweet potato chips

Publication . Gonçalves, Elsa M.; Pereira, Nelson; Silva, Mafalda; Alvarenga, Nuno; Ramos, Ana Cristina; Alegria, Carla; Abreu, Marta

The drying process is an essential thermal process for preserving vegetables and can be used in developing dried products as healthy alternative snacks. The effects of air-drying conditions using a convection dryer with hot air at different temperatures (60 , 65 , 70 , 75 , and 80 C, in the range 5–200 min, at a fixed air speed of 2.3 m/s) were tested on the quality of slices (2.0 0.1 mm) of dried sweet potato (Bellevue PBR). For each time and temperature, drying condition, physicochemical parameters (moisture content, CIELab color, texture parameters, total phenolic and carotenoid contents) and a sensory evaluation by a panel at the last drying period (200 min) were assessed. Drying time was shown to have a more significant effect than temperature on the quality of dried sweet potato as a snack, except for carotenoid content. Given the raw tuber content, thermal degradation (p < 0.05) of total phenolic compounds (about 70%), regardless of tested conditions, contrasted with the higher stability of total carotenoids (<30%). The dried product, under optimal conditions ( 75 C for 200 min), achieved a moisture content ( 10%) suitable for preservation, providing a crispy texture with favourable sensory acceptance and providing a carotenoid content similar to the raw product.

2023-03Journal article

Open access

Multi-Target Alternative Approaches to Promoting Fresh-Cut Carrots’ Bioactive and Fresh-like Quality

Publication . Alegria, Carla; Gonçalves, Elsa; Moldão, Margarida; Abreu, Marta

Fresh-cut fruits and vegetables, as near-fresh foods, are a quick and easy solution to a healthy and balanced diet. The rapid degradation of nutritional and sensory quality during the processing and storage of a product is critical and plant-type-dependent. The introduction of disruptive technological solutions in fresh-cut processing, which could maintain fresh-like quality with less environmental impact, is an emerging research concept. The application of abiotic stress treatments (heat shock and UV-C) induces metabolic responses and microbial effects in plant tissues, potentially slowing down several quality senescence pathways. The previously selected combined and single effects of heat shock (100 C/45 s; in the whole root) and UV-C (2.5 kJ/m2) treatments and two packaging conditions (oriented polypropylene (OPP) vs. micro-perforated OPP films) on controlling critical degradation pathways of fresh-cut carrots and on promoting bioactive and sensory quality during storage (5 C, 14 days) were studied. Among the tested combinations, synergistic effects on the quality retention of fresh-cut carrots were only attained for applying heat shock associated with micro-perforated OPP film packaging. Its effects on reducing (3.3 Log10 CFU/g) the initial contamination and controlling microbiological spoilage (counts below the threshold limit of 7.5 Log10 CFU/g), increasing the bioactive content (38% and 72% in total phenolic content and chlorogenic acid, respectively), and preserving fresh quality attributes prove to be a viable alternative technology for shredded carrot processing

2022Journal article

Open access

Valorisation of wasted immature tomato to innovative fermented functional foods

Publication . Pereira, Nelson; Farrokhi, Mahsa; Vida, Manuela; Lageiro, Manuela; Ramos, Ana Cristina; Vieira, Margarida C.; Alegria, Carla; Gonçalves, Elsa M.; Abreu, Marta

In this study, the lactic fermentation of immature tomatoes as a tool for food ingredient production was evaluated as a circular economy-oriented alternative for valorising industrial tomatoes that are unsuitable for processing and which have wasted away in large quantities in the field. Two lactic acid bacteria (LAB) were assessed as starter cultures in an immature tomato pulp fermentation to produce functional food ingredients with probiotic potential. The first trial evaluated the probiotic character of Lactiplantibacillus plantarum (LAB97, isolated from immature tomato microbiota) andWeissella paramesenteroides (C1090, from the INIAV collection) through in vitro gastrointestinal digestion simulation. The results showed that LAB97 and C1090 met the probiotic potential viability criterion by maintaining 6 log10 CFU/mL counts after in vitro simulation. The second trial assessed the LAB starters’ fermentative ability. Partially decontaminated (110 C/2 min) immature tomato pulp was used to prepare the individually inoculated samples (Id: LAB97 and C1090). Non-inoculated samples, both with and without thermal treatment (Id: CTR-TT and CTR-NTT, respectively), were prepared as the controls. Fermentation was undertaken (25 C, 100 rpm) for 14 days. Throughout storage (0, 24, 48, 72 h, 7, and 14 days), all the samples were tested for LAB and Y&M counts, titratable acidity (TA), solid soluble content (SSC), total phenolic content (TPC), antioxidant capacity (AOx), as well as for organic acids and phenolic profiles, and CIELab colour and sensory evaluation (14th day). The LAB growth reached ca. 9 log10 CFU/mL for all samples after 72 h. The LAB97 samples had an earlier and higher acidification rate than the remaining ones, and they were highly correlated to lactic acid increments. The inoculated samples showed a faster and higher decrease rate in their SSC levels when compared to the controls. A nearly two-fold increase (p < 0.05) during the fermentation, over time, was observed in all samples’ AOx and TPC (p < 0.05, r = 0.93; similar pattern). The LAB97 samples obtained the best sensory acceptance for flavour and overall appreciation scores when compared to the others. In conclusion, the L. plantarum LAB97 starter culture was selected as a novel probiotic candidate to obtain a potential probiotic ingredient from immature tomato fruits.

2023-04Journal article

Open access