Verbascum sinaiticum (Qetetina or yeahya Joro) is a medicinal plant with secondary metabolites such as phenolics, flavonoids, glycosides, saponins, and alkaloids. This study was designed to optimize the ultrasonic-assisted extraction (UAE) parameters to enhance the phenolic content and characterize the phenolic compounds using ultra-high-performance liquid chromatography, coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-ESI-QTOF-MS/MS), and antioxidant activities in Verbascum sinaiticum extract. Extraction time, sample-to-solvent ratio, and extraction temperature were considered for UAE optimization. It was found that UAE generated the highest extraction yield (21.6%), total phenolic content (179.8 GAE mg/g), total flavonoid content (64.49 CE mg/g), DPPH (61.85 µg/mL), and ABTS (38.89 µg/mL) when compared to maceration extraction. Metabolite analysis in this study showed the detection of 17 phenolic compounds, confirming antioxidant capacities. The optimization parameters have significant effects on phenolic compounds. Scanning electron microscopy showed the presence of structural changes when UAE was used over the maceration method. The optimized UAE parameters for extraction temperature (41.43 °C), sample-to-solvent ratio (36.32 g/mL), and extraction time (33.22 min) for TPC were obtained. This study shows the potential application for UAE of Verbascum sinaiticum leaves in the development of pharmaceutical and nutraceutical products.

Verbascum sinaiticum (V. sinaiticum), locally known as “Qetetina” in Ethiopia, is a rich source of phenolic compounds, but its stability and sensory limitations restrict its application. This study evaluated the physicochemical, functional, morphological, structural, storage stability, and in vitro digestibility characteristics of V. sinaiticum extract encapsulated with 100% Gum Arabic (GA), 100% maltodextrin (MD), and a mixed coating material (MD:GA = 8:2 ratio) using freeze-drying. MD-based microcapsules demonstrated superior functional properties, including high water solubility (98.48%), low moisture content (1.36%), low hygroscopicity (14.61%), and high encapsulation efficiency (81.31%). During 32 days of storage, MD microcapsules retained 71.84% of total phenolic content and showed minimal release under gastric and thermal conditions, while GA encapsulates were less stable. Structural analysis using XRD, FTIR, and SEM confirmed successful encapsulation, with compact morphology, consistent phenolic preservation, and structural integrity. Furthermore, encapsulation masked the undesirable sensory attributes of the extract, enhancing its potential use in nutraceuticals. Overall, freeze-drying with MD provided the most effective encapsulation system, significantly improving the stability and storage potential of V. sinaiticum extract.

The aim of this study was to evaluate the effects of different drying methods on bioactive compounds and to analyze their composition in Verbascum sinaiticum (V. sinaiticum) leaf extracts using UHPLC-ESI-QTOF-MS/MS. V. sinaiticum is traditionally used as an herbal medicine, yet it has undergone limited scientific investigations regarding its secondary metabolites. V. sinaiticum leaves were dried using oven dryers at 50 °C, 60 °C, and 70 °C, as well as a freeze dryer. The leaves were then extracted using 50% and 70% aqueous ethanol and 100% aqueous solutions. The results showed that the highest contents of TPC and TFC were observed when 70% aqueous ethanol was used during freeze drying, reaching 181.73 mg GAE/g dw and 78.57 mg CE/g dw, respectively. The strongest correlations were observed between the TFC and DPPH radical scavenging activity (0.9082), followed by TPC and ABTS assays (0.8933) and TPC and DPPH (0.8272). In the FTIR analysis, freeze drying exhibited a lower intensity of the phenolic -OH functional groups, contrasting with significant denaturation observed during oven drying at 70 °C. Metabolite analysis identified 29 compounds in V. sinaiticum leaves, further confirming the presence of 14 phenolic and flavonoid compounds, including kaempferol, catechin, gallic acid, and myricetin derivatives, consistent with the experimentally observed antioxidant capacity. This study highlights the impact of drying methods on the bioactive composition of V. sinaiticum and underscores its potential as a source of antioxidants for food, nutraceutical, and pharmaceutical applications.

The efficacy of plant-derived antimicrobials in meat systems is frequently limited by interactions with proteins, lipids, and other food matrix components that reduce the bioavailability and antimicrobial activity of phytochemicals. This study evaluated the antimicrobial effectiveness of Verbascum sinaiticum (V. sinaiticum) leaf extract encapsulated using maltodextrin (MD), gum arabic (GA), and a maltodextrin–gum arabic blend (MDGA, 8:2 w/w) through freeze-drying for application in raw beef during refrigerated storage (4 °C). The encapsulation systems exhibited process yields of 42.5–54.7%, encapsulation efficiencies of 78.3–92.5%, and loading capacities of 18.5–24.3 mg GAE/g DW, with MDGA showing the highest encapsulation efficiency. The effects of encapsulation on microbial inhibition, physicochemical properties, and sensory quality were investigated over 15 days of storage. Aerobic plate counts in the control increased from 3.04 to 8.26 log CFU/g, whereas encapsulated treatments showed significantly lower final counts (p < 0.05), reaching 7.89 log CFU/g (MD), 7.96 log CFU/g (MDGA), and 7.95 log CFU/g (GA). Similarly, encapsulated treatments reduced Escherichia coli counts during storage, with maltodextrin (MD) exhibiting the greatest inhibitory effect (6.23 × 10⁵ CFU/g) compared with the control (6.93 × 10⁵ CFU/g) on day 15. However, reductions in Staphylococcus aureus, E. coli, Candida albicans, and Bacillus cereus remained below 1 log CFU/g, indicating limited antimicrobial efficacy under the tested conditions. All encapsulated treatments slowed pH increases during storage (6.20–6.34) relative to the control (6.62) on day 15 and preserved aroma quality throughout the storage period. Overall, encapsulation improved the antimicrobial performance of V. sinaiticum extract compared with the free extract, particularly in MD-based systems; however, the antimicrobial effects in beef remained modest. These findings highlight both the potential and current limitations of encapsulated plant-derived antimicrobials for meat preservation and emphasize the need for optimized delivery systems to enhance efficacy in complex food matrices.