Volume 20 Issue 3

This study presents an eco-friendly strategy to valorize Polygonatum cryptonym Hua flavonoids (PC) from the residues of polysaccharide extraction by synthesizing silver nanoparticles (PC-AgNPs) with enhanced bioactivity. Optimized synthesis (pH 7.5, 10 mM Ag⁺, 55 °C, 30 min) yielded monodisperse, spherical PC-AgNPs (avg. 16.2 nm) with face-centered cubic crystal structure. Nanoparticles showed remarkable scavenging ability for DPPH free radical (SC₅₀ = 2.61 µg/mL) and ABTS free radical (SC₅₀ = 1.65 µg/mL) compared to the native PC samples. The PC-AgNPs were incorporated into polylactic acid (PLA) films (1% w/w), achieving superior mechanical performance (tensile strength: 54.6 MPa; elongation at break: 6.0%) while demonstrating broad-spectrum antimicrobial activity against E. coli, S. aureus, and A. niger. Mechanistic studies revealed that the nanocomposite film disrupted bacterial membrane integrity in E. coli. Applied to litchi preservation at -18°C, the 1%NPs/PLA coating effectively maintained mitochondrial enzyme activities (Succinate dehydrogenase, Cytochrome c oxidase, H⁺-ATPase, Ca²⁺-ATPase) at more than 80% of fresh fruit levels for a certain storage life, significantly delaying senescence compared to controls. These findings establish PC-AgNPs/PLA as a dual-functional active packaging material that synergistically combines antioxidant reinforcement, antimicrobial protection, and physiological regulation for postharvest fruit preservation.

The medicinal and aromatic plant species naturally found in Türkiye are particularly noteworthy. Among them, Phlomis L., a genus within the Lamiaceae family, stands out for its numerous species. This study, conducted in Uludağ (Bursa), aimed to analyze the morphological traits, volatile components, ratios, and molecules present in the leaves and flowers of Phlomis russeliana (Sims) Bentham and P. armeniaca Willd. Samples were collected during their flowering period using a random sampling method. Their morphological characteristics were analyzed using Microsoft Excel and IBM SPSS software, while the volatile components of the leaf and flower samples were identified through the HS-SPME/GC-MS method. The morphological characteristics of Phlomis russeliana and P. armeniaca were examined in detail. The leaf widths and lengths, petiole lengths, number of flowers, petal lengths, sepal lengths were measured. 32 different components were identified in P. russeliana and 43 different components in P. armeniaca, summing up to 56 different components. The main components identified were caryophyllene (31.6%; 26.4%), (E)-β-farnesene (19.6%; 25.2%), and germacrene-D (25.7%; 16.5%), respectively. Such studies are crucial for enhancing the protection and sustainable management of non-wood forest products, which significantly contribute to our country’s economy and play a pivotal role, especially in rural economies.

Enzymatic refining offers a sustainable alternative to mechanical refining for enhancing the quality of recycled paper fibers. This review examines (a) the benefits and limitations of enzymatic refining and (b) the most commonly used enzymes and their effectiveness. Studies from 2008 to 2023 were systematically analyzed using PRISMA screening to assess enzyme types, energy savings, and paper property improvements. Findings indicate that enzymatic refining reduces energy consumption by up to 20% while improving fiber bonding and drainage. Cellulases and hemicellulases are the most effective enzymes, enhancing mechanical strength and reducing water use. However, enzymatic refining alone is often insufficient, requiring additional mechanical refining for optimal results. Industrial adoption of enzymatic refining remains limited due to challenges in process integration and reaction optimization. This study highlights the role of this kind of refining in advancing circular economy goals and emphasizes future research needs, including enzyme formulation optimization and the development of scalable, one-step refining solutions.