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The present study was designed to extract the lignin fraction from date palm tree leaves and explore its incorporation into carboxymethyl cellulose (CMC) based composite films at varying concentrations as reinforcing agent. Structural studies revealed that the interaction between lignin and CMC improved the film characteristics and showed good compatibility between these polymers. X-ray diffraction (XRD) results revealed that the crystalline structure of CMC and lignin (CMC-Lignin) films was enhanced by the addition of lignin. The addition of lignin significantly enhanced the mechanical properties in terms of the tensile strength (TS) and elongation at break (EAB) of the CMC-Lignin films from 18.29 to 32.61 MPa and 32.5–45.3%, respectively. Physical properties in terms of thickness, solubility, moisture content, and water vapor permeability (WVP) were improved from 0.09 to 0.14 mm, 84.75 to 51.03%, 31.34 to 19.30%, and 4.98 to 1.08 × 10−10 g m−1s−1Pa−1, respectively. The addition of lignin changed the optical properties of the films, making them darker and opaquer. CMC-Lignin films showed improved antioxidant and antimicrobial properties and manifest as viable alternatives to plastic packaging and can be successfully used as a sustainable packaging material in the food industry. [ABSTRACT FROM AUTHOR]

Carboxymethyl cellulose (CMC) based edible films, reinforced with date seed powder (DSP) were investigated. An increasing concentration of DSP (5%, 10%, 15%, and 20%) was added to the carboxymethyl cellulose film-forming solution. The physical, antioxidant, antibacterial, mechanical, structural, and thermal properties of the films were studied to investigate the effect of DSP incoportation. The addition of DSP increased the thickness of the films from 0.11 to 0.15 mm, reduced the solubility (95.31–77.23%), and exhibited antibacterial activity against the food-borne pathogens: Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium. Especially for Escherichia coli, and Salmonella typhimurium, the antimicrobial activity was seen only at high concentrations (15% and 20%) of DSP. Besides, the antioxidant capacity increased with increasing concentration of DSP: the DPPH radical scavenging activity increased from 0 to 51.98% while ABTS increased from 0 to 84.58%, when the concentration of DSP increased from 0 to 20%. In addition, the water vapor permeability of the films improved but the tensile strength decreased from 7.66 MPa to 5.12 MPa and the elongation at break increased from 79.03 to 85.95%. This study clearly showed that the DSP could be valorised as an active and reinforcing component in CMC-based biodegradable and edible films to create natural active food packaging. [ABSTRACT FROM AUTHOR]

In this study, eight different natural deep eutectic solvents (NADESs) were utilized in combination with microwave-assisted extraction (MAE) as a green technique for the optimal extraction and achieve enhanced antioxidant activity of bioactive compounds from date seed powder (DSP). The two most efficient NADESs (choline chloride-lactic acid (ChCl-LA) and choline chloride-xylose (ChCl-Xylo) were further optimized for (MAE) using response surface methodology (RSM). Three factors considered for optimization were temperature (20, 55, and 80 ℃), irradiation time (5, 12.5, and 20 min), and percentage NADES contents (25, 55, and 85%). Total phenolic compounds (TPC), ferric reducing antioxidant power (FRAP), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) activity were used as response factors. The optimal conditions were temperature (80 °C), irradiation time (5 min), and NADES contents (63%) for ChCl-LA, and temperature (80 °C), irradiation time (20 min), and NADES contents (50%) for ChCl-Xylo, respectively. At the optimized conditions, the highest values for FRAP, DPPH, and TPC obtained were 771.54 and 734.34 mM TE/g powder, 503.75 and 396.73 mM TE/g powder, and 147.92 and 234.65 mg GAE/g powder respectively, for ChCl-LA and ChCl-Xylo. The main phenolic compounds found in the selected extracts were catechin, 3,4-dihydroxybenzoic acid, and caffeic acid. This study infers that the utilization of MAE with appropriate NADESs as green extraction approach under optimized conditions can produce enhanced yield of bioactive compounds from date seeds. The synthesized NADES after appropriate toxicity studies could be used in replacement of conventional solvents which could be utilized in the food, pharmaceutical, and cosmetic industry as green and safe ingredients. [ABSTRACT FROM AUTHOR]

Bio-based active food packaging containing natural antioxidants has gaining great attention these days. The food industry resulted in huge amount of waste rich in natural antioxidant and utilization of these wastes is very important from environmental viewpoint. In this study, apple peel was used to produce apple peel nanoparticles and later, chitosan (CS) and gelatin (G) based novel functional films were successfully fabricated. The prepared films were characterized for their structure, potential interaction and thermal stability. In addition, tensile strength and physical properties were also determined. Scanning electron microscopy (SEM) results revealed that higher concentration of apple peel ethanolic extract (APEE) triggered the sintering of nanoparticles within the films. The data of Fourier transform-infrared spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) revealed that the presence of apple peel related compounds in the films resulted decrease in availability of hydroxyl groups within the polymer matrix. The addition of APEE into CS/G significantly enhanced the physical properties of the film by increasing its thickness while solubility, swelling ratio, and water vapor permeability were decreased. It could be inferred that CS/G-APEE films exhibited good antioxidant properties, indicating that it could be developed as a bio-nanocomposite food packaging material for the food industry. [ABSTRACT FROM AUTHOR]

In this study, theaflavins (TF1, TF2A, TF2B and TF3) were prepared from black tea and their interaction with bovine serum albumin (BSA) was explored by fluorescence and CD spectroscopy. The results showed that the structures of theaflavins exhibited significant effects on the binding/quenching process, and the binding affinity increased with the increase of molecular weight of theaflavins and the presence of galloyl moiety. The quenching effects showed a sequence as TF3 > TF2A > TF2B > TF1, demonstrating the important role of the galloyl moiety on the C-3 position of theaflavins. CD spectra indicated that TF3 in high concentration could change the skeleton structure of BSA and induce the unfolding of BSA secondary structure. The present results provide a new perspective for better understanding of the likely physiological fate of theaflavins and help to control the functional characteristics of food. [ABSTRACT FROM AUTHOR]