The increasing environmental and health concerns associated with conventional chemical coagulants have stimulated the search for natural, biodegradable, and renewable alternatives for water and waste-water treatment. This study investigated different cultivars of common bean (Phaseolus vulgaris) as potential sources of natural coagulants and evaluated the effects of cultivar, harvest year, extraction solvent, pH, and raw material origin on coagulation activity. Natural coagulants were obtained from 12 common bean cultivars by ultrasound-assisted extraction using distilled water and 0.5 mol/L NaCl. In addition, the feasibility of utilizing harvest and sorting residues of the Sremac cultivar as a source of natural coagulants was evaluated. Coagulation performance was assessed by jar tests using kaolin-based model water with an initial turbidity of 200 NTU at pH 6, 8, and 10. All investigated cultivars exhibited coagulation activity, although substantial differences were observed among the extracts. The highest activities were obtained from the Balkan, Gradistanac, and Maksa cultivars, with maximum coagulation activities of 95.4% ± 0.08%, 94.5% ± 0.22%, and 90.1% ± 0.08%, respectively. In general, pH 6 was the most favorable condition for coagulation, while extracts prepared using 0.5 mol/L NaCl frequently exhibited higher activities than those obtained using distilled water. The harvest year also affected coagulation performance, particularly for the Levac cultivar. Extracts obtained from bean sorting residues showed lower coagulation activities than those prepared from the corresponding cultivar, although their use may provide a means of valorizing an otherwise low-value waste material. Overall, the results demonstrate that common bean, particularly the Gradistanac, Balkan, and Maksa cultivars, represents a promising and readily available source of natural coagulants for water and wastewater treatment.
This study aimed to investigate the influence of hot trub (HT) drying methods on the content of bio-active compounds (total phenols and flavonoids). The research evaluated the effects of various drying methods - conventional drying (50, 65, and 80°C), vacuum drying (50, 65, and 80°C at -0.95 bar), and lyophilization (-40°C at 0.128 mbar) - on the total phenolic and flavonoid contents, as well as the anti-oxidant activity (DPPH assay), of HT extracts. The results indicated that the applied drying method and temperature influenced the retention of target bioactive compounds and antioxidant capacity. Although freeze-drying preserved the highest content of flavonoids and overall antioxidant capacity, vacuum drying at moderate temperatures (50 - 65 °C) represents the most viable industrial approach, offering a superior balance between shorter drying duration, reduced operational demands, and high retention of bioactive polyphenols. These findings, based on a single processing batch, should be confirmed through further studies incorporating independent drying replicates.
Yoghurt is a widely consumed fermented dairy product recognized for its nutritional benefits. Improving the sensory attributes and nutritional properties of yoghurts can be done by the addition of fruits. Banana is also a highly nutritious fruit and a rich source of phenolic compounds, resistant starch, fiber, and protein, and also contains natural sugars. Owing to these benefits, the incorporation of banana in yoghurt would enhance its nutritional benefits and sensory attributes. This study focuses on evaluating the effects of spray-dried banana powder concentration (control (0%), 20%, 25% and 30%) and fermentation time (4 and 6 hours) on selected vitamin content and sensory attributes of the yoghurts. Vitamin C and ?-carotene, total flavonoid, phenolic content, and proximate composition of the yoghurt were evaluated using Analysis of Variance (ANOVA), and sensory evaluation was also conducted using a 9-point hedonic scale. The incorporation of banana powder and varied fermentation time increased the vitamin C, total phenolic, and ?-carotene content at 20% for 4 hours, 30% for 6 hours, and 25% for 4 hours, respectively. Samples A2 and D1 were not significantly different for total flavonoids. The sensory attributes of the yoghurt were most preferred at 30% spray-dried banana powder concentration fermented for 6 hours. However, the control showed the lowest vitamin C and ?-carotene content and also the lowest sensory scores, most expected to be due to no addition of fruits. This study proposes that yoghurts incorporated at 20-30% and fermented for 6 hours improve yoghurt?s nutritional value as well as sensory attributes.
The present study deals with the modeling of antibacterial activity of a series of forty-four compounds consisted of aliphatic sulfonamide derivatives, s-triazine based chalcones and arylpropenone derivatives towards Listeria monocytogenes, a pathogenic bacteria causing the infections well-known as listeriosis. The purpose of the study was to reveal the molecular features (physicochemical and topological molecular descriptors) that influence the antibacterial activity, as well as to form quantitative structure-activity relationship (QSAR) models to predict minimum inhibitory concentrations (MIC) of the analyzed derivatives against L. monocytogenes. The research methodology included molecular modeling that provided molecular descriptors that were further correlated with antibacterial activity, as well as correlation and regression analyses. Multiple linear regression (MLR) and artificial neural networks (ANN) regression approaches were applied in QSAR modeling and each approach resulted in one QSAR model. The QSAR models were evaluated applying cross-validation methodology. The applicability domains for each QSAR model were defined. Generally, the ANN modeling resulted in a more reliable predictive model. Additionally, hierarchical cluster analysis (HCA) was performed based on molecular descriptors in order to gain an overview of structural similarities and differences between the analyzed compounds. The HCA indicated certain overlapping between aliphatic sulfonamides and arylpropenones in the space of considered molecular descriptors. To conclude, the obtained results can be considered a useful tool in estimation and prediction of antibacterial activity against L. monocytogenes.
Current trends in food packaging emphasize the use of biodegradable, renewable materials instead of fossil-derived polymer materials. In this study, edible films were prepared from both pure casein and casein extracted from skim milk powder. Potassium sorbate was incorporated as a preservative in the film-forming solutions. The study was conducted in two sequential stages. In the first stage, various concentrations of glycerol (1%, 2%, and 3% v/v) were tested to identify the optimal level of plasticizer based on the physical and mechanical properties of the films. Once the optimal glycerol concentration was determined, it was kept constant for the preparation of films reinforced with silver nanoparticles (AgNPs). Subsequently, AgNPs were incorporated at different concentrations (20, 30, 40, and 50 ppm), and their effects on the physical, mechanical, and antimicrobial properties of the films were evaluated. The results showed that glycerol improved elongation at break but reduced tensile strength. The optimum concentration (2% v/v) provided a balance between tensile strength (5.4 MPa) and elongation at break (26%) for films prepared from extracted casein. A decrease in water vapour permeability (WVP) was observed with increasing AgNPs concentration, where WVP decreased by 20.12% and 23.76% at 50 ppm for pure and extracted casein films, respectively. Mechanical properties were also enhanced, with tensile strength increasing by 63.41% and 35.18% for extracted and pure casein films, respectively. Furthermore, AgNPs significantly reduced the total bacterial count by 90% and 70% for extracted and pure casein films, respectively, as well as yeast and mold counts.
