FT-IR and HPLC analysis of silver fir (Abies alba Mill.) bark compounds from different geographical provenances.

Fourier Transform Infrared Spectroscopy (FT-IR) and High-Performance Liquid Chromatography (HPLC) could be applied to study the provenance of wood, specifically the differentiation of wood resources, as well as the identification of chemical compounds that are connected to the changes that occur in wood as a result of drying treatments. To test this hypothesis, the bark of silver fir (Abies alba Mill.) from trees belonging to seven different geographical provenances was studied, using samples dried at three different temperatures (60, 80, and 100 °C). FT-IR spectroscopy revealed different band assignments in the mid-infrared region depending on fir provenances, whereas the vibrational bands of the biomass functional groups tended to shift to lower wavenumbers. Significant differences were identified between the chemical compounds in the bark depending on the provenances. The largest proportion of the total phenolics was represented by the epicatechin gallate, epicatechin, catechin, and procyanidin dimer B1. Exploratory data analysis was performed using principal component analysis (PCA), hierarchical clustering, and Pearson correlations. This allowed a comparative evaluation of the samples and interpret the findings according to the geographical provenances, respectively ecological conditions in the areas of origin, but also the influence of the drying temperatures of the samples on chemical compounds. The precipitation in the areas of origin decreased total phenolics in silver fir bark samples, and total phenolics differed not only due to the geographic provenance, but also due to drying temperature.

Phenolic profile of micro- and nano-encapsulated olive leaf extract in biscuits during in vitro gastrointestinal digestion.

Olive leaf was characterized by a high content of phenols and flavonoids (oleuropein, luteolin, and their derivatives), presenting functional and health-related properties. The chemical instability of phenolics through technological processes and their degradation in the digestive system may negatively impact them, leading to lower absorption. This study evaluates the phenolic profile of micro- and nano-encapsulated olive leaf extract in biscuits during the INFOGEST static in vitro digestion, aiming to enhance stability and sensorial properties. Ultrasound-assisted extraction and chromatography characterized the extract, while spray drying (maltodextrin-glucose) and nano-encapsulation (maltodextrin, whey protein isolate, and arabic gum) techniques were used with specific solutions. Encapsulated formulations underwent microscopy (TEM, SEM) and encapsulation efficiency analysis. Micro- and nano-encapsulation improved biscuit functionality by enhancing phenolic stability during digestion. However, the highest concentration adversely affected sensory and textural parameters. These findings contribute to developing functional food products enriched with bioactive compounds, providing improved health benefits while maintaining sensory attributes.