Detecting changes in industrial pollution by analyzing heavy metal concentrations in tree-ring wood from Romanian conifer forests.

The impact of air pollution on forests, especially in urban areas, has been increasingly discussed recently. Many pollutants, including heavy metals, are released into the atmosphere from various sources, such as mining, non-ferrous metal processing plants, and fossil fuel combustion. These pollutants can adversely affect not only tree growth but also other species, including humans. This study compared the concentrations of several elements in tree-ring wood from two conifer species (Silver fir, Abies alba; Norway spruce, Picea abies) growing in polluted and unpolluted areas. Two regions in northern Romania (Bicaz and Tarnița) that were subjected to historical pollution changes were selected. Two chemical analyses were used: inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF). The silver fir trees from the intensively polluted area in the Tarnița region were negatively impacted by industrial pollution: the Mn concentrations were, on average, three times higher in polluted areas than in unpolluted areas (ca. 30 vs. 10 mg kg-1). This finding was consistent for both ICP-MS and XRF analyses. However, in Norway spruce, this difference was found only in the XRF data, which detected Mn concentrations seven times higher in trees from polluted areas than those from unpolluted areas (ca. 700 vs. 100 mg kg-1). In the Tarnița region, Norway spruce accumulated more heavy metals than silver fir, but the most pronounced differences between polluted and unpolluted areas were found in silver fir. The two analytical methods are commonly used to determine metal concentrations in wood, and they complement each other, with ICP-MS having a low detection limit for some elements and XRF having higher detection limits and better accuracy. Each method has its advantages and disadvantages, and the optimal method depends on many factors, such as the type of heavy metal analyzed, its concentration in wood, sample type, cost, analysis time, and sample preparation.

Biopolymers-Based Macrogels with Applications in the Food Industry: Capsules with Berry Juice for Functional Food Products.

The present study focused on the development of gel-based capsules from sodium alginate and the fresh juice from different berries: chokeberry, sea buckthorn, and blueberry. Obtained through the extrusion method, the macrocapsules were added into yogurt, a well-known and consumed dairy product. In order to establish the changes that can occur for the food product, the samples were tested over 7 and 15 days of storage in refrigeration conditions. According to the results, the antioxidant activity increased during storage and gels can represent a good option for bioactive substances' encapsulation. Sensorial analysis performed indicated that consumers are open to consuming yogurt berry capsules and, according to the results observed in the scientific literature, they no longer rejected the product due to the bitterness and sourness of sea buckthorn or aronia. Sea buckthorn capsules were brighter (L*) than chokeberry and blueberry capsules due to carotene content and dark colors. Minimal diameter variations and small standard deviations (SD = 0.25/0.33) suggest that extrusion methods and the Caviar box are good for gel capsule development. Yogurt luminosity varied with capsules; control had the highest, followed by sea buckthorn yogurt. Samples with chokeberry and blueberry (dark) capsules had lower luminosity. Over 8 and 15 days, luminosity slightly decreased, while a* and b* (hue and saturation) increased. Post-storage, the sample with chokeberry capsules showed a light purple color, indicating color transfer from capsules, with increased antioxidant activity. Differences between the samples and control were less pronounced in the sample with sea buckthorn capsules. Values for color differences between yogurt samples during the storage period revealed the most significant difference during the first storage period (day 1-8), with blueberries showing the lowest difference, indicating the stability of the blueberry capsules' wall during storage.