Physicochemical Properties and Antioxidant Activity of Portuguese Craft Beers and Raw Materials.

There is an increase in the popularity of craft beer, which is produced by small, independent, and traditional breweries. Since craft beer popularity is rising in Portugal this research focused on assessing physicochemical parameters, total phenolic content (TPC) and the antioxidant capacity of Portuguese craft beers and raw materials used in beer production. In this experimental study, 19 beer samples were analyzed. Parameters such as pH, Total Acidity, Reducing Sugar Content and TPC were evaluated. For the determination of antioxidant activity, DPPH scavenging activity and metal chelating activity (MCA) were analyzed in all samples. Craft beers demonstrated a high phenolic content (ranging from 343.78 mg GAE/L to 2172.49 mg GAE/L), significantly different from industrial beers. Craft beers demonstrated a higher inhibition of DPPH radicals and higher MCA than the raw materials. DPPH inhibition ranged from 36.5% to 96.0% for malt and 64.7% to 79.6% in hops samples. MCA also varied between the different samples, with results of 12.0% to 24.8% in malt samples and 3.8% to 23.5% in hops. Raw materials can potentially influence the antioxidant activity of the resulting beer. Positive correlations between TPC and physicochemical properties can be useful to help consumers choose beers with added value for health.

On the dual nature of lichen-induced rock surface weathering in contrasting micro-environments.

Contradictory evidence from biogeomorphological studies has increased the debate on the extent of lichen contribution to differential rock surface weathering in both natural and cultural settings. This study, undertaken in Côa Valley Archaeological Park, aimed at evaluating the effect of rock surface orientation on the weathering ability of dominant lichens. Hyphal penetration and oxalate formation at the lichen-rock interface were evaluated as proxies of physical and chemical weathering, respectively. A new protocol of pixel-based supervised image classification for the analysis of periodic acid-Schiff stained cross-sections of colonized schist revealed that hyphal spread of individual species was not influenced by surface orientation. However, hyphal spread was significantly higher in species dominant on northwest facing surfaces. An apparently opposite effect was noticed in terms of calcium oxalate accumulation at the lichen-rock interface; it was detected by Raman spectroscopy and complementary X-ray microdiffraction on southeast facing surfaces only. These results suggest that lichen-induced physical weathering may be most severe on northwest facing surfaces by means of an indirect effect of surface orientation on species abundance, and thus dependent on the species, whereas lichen-induced chemical weathering is apparently higher on southeast facing surfaces and dependent on micro-environmental conditions, giving only weak support to the hypothesis that lichens are responsible for the currently observed pattern of rock-art distribution in Côa Valley. Assumptions about the drivers of open-air rock-art distribution patterns elsewhere should also consider the micro-environmental controls of lichen-induced weathering, to avoid biased measures of lichen contribution to rock-art deterioration.

The introduction and spread of rye (Secale cereale) in the Iberian Peninsula.

Some of the earliest Western European macroremains of rye (Secale cereale) have been recently recovered in Northwest Iberia. However, the chronological and cultural contexts of these remains have not been yet exhaustively analysed. To address this gap of research, previous and unpublished assemblages have been reviewed and analysed through an analytical set of methods: biometry, radiocarbon dates and integrating the remains of rye in the broad archaeobotanical record of the region. Results show the earliest macroremains of rye in the Iberian Peninsula date to a period between the 3rd century and the first half of the 1st century BCE. Rye was usually found in assemblages dominated by spelt and other cereals, in whose fields it was likely acting as a weed. There is no record of rye for about the two following centuries, after which it is probably reintroduced, now as a crop. It is found in several sites from the 3rd-4th centuries CE onwards, suggesting it is a staple crop as in other regions in Europe. Significant differences in grain size are only recorded in a 10th-11th century settlement, suggesting few changes in grain morphometry before Medieval times.

Late Quaternary range shifts of marcescent oaks unveil the dynamics of a major biogeographic transition in southern Europe.

Marcescent forests are ecotones distributed across southern Europe that host increased levels of biodiversity but their persistence is threatened by global change. Here we study the range dynamics of these forests in the Iberian Peninsula (IP) during the Late Quaternary, a period of profound climate and anthropic changes. We modeled and compared the distribution of eight oak taxa for the present and two paleoclimatic environments, the Last Glacial Maximum (LGM, ~ 21 kya) and the Mid-Holocene (MH, ~ 6 kya). Presence records were combined with bioclimatic and topographic data in an ensemble modelling framework to obtain spatial projections for present and past conditions across taxa. Substantial distribution shifts were projected between the three studied periods, that were explained by precipitation, winter cold and terrain ruggedness. Results were congruent with paleoclimatic records of the IP and showed that range shifts of these contact zones concurred with range dynamics of both Submediterranean and Temperate oaks. Notably, the distribution ranges of hybrid oaks and marcescent forests matched throughout the late Quaternary. This study contributes to unveil the complex Late-Quaternary biogeography of the ecotone belt occupied by marcescent forests and, more broadly, of Mediterranean oaks. Improved knowledge of species' responses to climate dynamics will allow us to anticipate and manage future range shifts driven by climate change.