Characterization analysis of date fruit pomace: An underutilized waste bioresource rich in dietary fiber and phenolic antioxidants.

Date fruit pomace (DFP), an abundant byproduct of the date syrup industry, is currently underutilized. It is either fed to animals or landfilled where it ferments, causing serious environmental issues. Proper waste management through valorization strategies is required to reduce the environmental impact of date waste and foster the transition of the date processing industry towards sustainability. The implementation of valorization strategies requires characterizing the DFP composition. Herein, four DFP samples of Emirati varieties were characterized in terms of compositional and functional properties. The fresh DFPs contained moisture (∼60.0 g/100 g). On a dry matter basis, DFPs contained total dietary fiber (∼45.5 g/100 g), residual sugars (∼35.3 g/100 g), protein (∼10.6 g/100 g), ash (∼4.1 g/100 g), and fat (∼1.3 g/100 g). They were also rich in nutritionally important elements such as potassium (∼145.7 ppm), calcium (∼46 ppm), phosphorus (∼28.7 ppm), and magnesium (∼26.7 ppm). The total phenolic content varied from 170 to 260 mg gallic acid equivalents GAE/100 g, making DFP a good source of antioxidants. Scanning electron microscopy measurements revealed the presence of fibrous bundle-like structures, whose thermal stability was confirmed by thermogravimetric analysis, showing the dominance of insoluble over soluble fiber. Higher water- and oil-holding capacities were found for dried desugared pomace. The high fiber, phenolic, and elemental content highlight the high nutritional value of DFP, which can be used as dietary supplement, while its sugar content can be used to produce value-added biochemicals via fermentation. Thus, DFP may represent a valuable bioresource for food and non-food applications.

Synergistic interactions, kinetic and thermodynamic analysis of co-pyrolysis of municipal paper and polypropylene waste.

Co-pyrolyzing mixed wastes of the different physicochemical kinds is often a challenge. This study reports the co-pyrolysis of homogeneous polypropylene plastic and paper wastes, highlighting their characteristics, synergetic effects, and kinetic and thermodynamic parameters using robust thermal gravimetric analysis technique. Results show that 20% paper in the blend improved the bulky density, fuel ratio from 0.09 to 0.13, maximum degradation temperature from 369.55 to 447.88 °C and thermal stability from 381.60 to 393.82 °C. The average activation energies of the blend from Flynn-Wall-Ozawa, Friedman and Coats-Redfern were 148.73 ± 7.87, 133.98 ± 11.59 and 143.74 ± 13.83 kJ/mol, respectively, lower than at least one of the homogenous wastes. All the enthalpy and Gibbs free energy values were positive, thus, endothermic non-spontaneous pyrolysis. In addition, average enthalpies for the mixed sample were lower than homogeneous polypropylene (from 159.57 ± 11.86, 153.74 ± 16.07 and 181.27 ± 28.90 to 143.60 ± 24.42, 128.86 ± 34.61 and 138.61 ± 41.32 kJ/mol, respectively) in all models, respectively. The entropy values for all samples were negative. They decreased with increasing conversion rates for mixed waste samples, indicating ease to reach thermodynamic equilibrium during pyrolysis. There is an insignificant difference between the experimental and the calculated TGA/DTG curves, signifying meagre synergetic effects. In addition, the 3D surface response for the conversion rate against temperature and heating rate showed closeness in results between the homogeneous and mixed waste. The results of this study are vital in handling municipal solid waste without any need for isolation during the conversion process to valuable products.

Biomimetic PLGA/Strontium-Zinc Nano Hydroxyapatite Composite Scaffolds for Bone Regeneration.

Synthetic bone graft substitutes have attracted increasing attention in tissue engineering. This study aimed to fabricate a novel, bioactive, porous scaffold that can be used as a bone substitute. Strontium and zinc doped nano-hydroxyapatite (Sr/Zn n-HAp) were synthesized by a water-based sol-gel technique. Sr/Zn n-HAp and poly (lactide-co-glycolide) (PLGA) were used to fabricate composite scaffolds by supercritical carbon dioxide technique. FTIR, XRD, TEM, SEM, and TGA were used to characterize Sr/Zn n-HAp and the composite scaffolds. The synthesized scaffolds were adequately porous with an average pore size range between 189 to 406 µm. The scaffolds demonstrated bioactive behavior by forming crystals when immersed in the simulated body fluid. The scaffolds after immersing in Tris/HCl buffer increased the pH value of the medium, establishing their favorable biodegradable behavior. ICP-MS study for the scaffolds detected the presence of Sr, Ca, and Zn ions in the SBF within the first week, which would augment osseointegration if implanted in the body. nHAp and their composites (PLGA-nHAp) showed ultimate compressive strength ranging between 0.4-19.8 MPa. A 2.5% Sr/Zn substituted nHAp-PLGA composite showed a compressive behavior resembling that of cancellous bone indicating it as a good candidate for cancellous bone substitute.

A New Green Composite Based on Plasticized Polylactic Acid Mixed with Date Palm Waste for Single-Use Plastics Applications.

Petroleum-based plastic is widely used in almost all fields. However, it causes serious threats to the environment owing to its non-biodegradable properties, which necessitates finding biodegradable alternatives. Here, date palm rachis (DPR) waste was used as a filler (30, 40, and 50 wt%) to form a biodegradable composite with polylactic acid (PLA) and achieve cost-performance balance. DPR-PLA composites were prepared using a melt-mixing extruder at 180 °C by varying mixing time, DPR composition, and plasticizer type and composition. The biodegradable testing specimens were prepared by compression molding and analyzed using physical, thermal, and mechanical characterizations. Scanning electron microscopy images indicated a uniform dispersion of DPR (90 µm) in the PLA matrix. The esterification reaction resulting from this interaction between DPR and PLA was confirmed by Fourier transform infrared spectroscopy. The 30 wt% DPR-PLA composite was considered the optimal composite with the lowest melt flow index (16 g/10 min). This work confirmed the superior effect of addition of 10 wt% of triethyl citrate (TEC) compared with polybutylene adipate terephthalate (PBAT) by the improvement in the elongation at break of the optimal composite from 2.10% to 4.20%. Moreover, the addition of 10 wt% of PBAT to the optimal composite resulted in a lower tensile strength (21.80 MPa) than that of the composite with 10 wt% of TEC (33.20 MPa). These results show the potential of using the proposed composite as an alternative material for single-use plastics such as cutlery.

Effective and sustainable adsorbent materials for oil spill cleanup based on a multistage desalination process.

Oil spills, which are often caused by crude oil transportation accidents, contaminate coastal waters and land and can harm aquatic life, seabirds, humans, and the entire ecosystem. Ocean currents and wind complicate oil spill cleanup and extend the oil spill area. This study proposes a new approach to control oil spills using solids recovered from the treatment of reject brine through a novel multistage desalination process. The aim is to produce applicable adsorbent for oil spill cleanup especially in the final cleaning stages. The multistage desalination process is based on the electrochemical treatment of high-salinity reject brine and Solvay and modified Solvay liquid effluents in a closed Plexiglas electrocoagulation cell. After the electrochemical treatment, the collected solids were dried and ground for utilization as adsorbents in oil spill cleanup. Results were promising for the adsorbent produced from the electrochemical treatment of the modified Solvay effluent. A maximum adsorption capacity of 2.8 g oil/g adsorbent was achieved, with an oil recovery of 98%. In addition, the regenerated solids after toluene extraction process were recycled and achieved an adsorption capacity of 2.1 g oil/g adsorbent in the second oil spill clean-up cycle. The structural and chemical characteristics of the adsorbents produced from the multistage desalination process were investigated using X-ray powder diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Results support the adoption of the collected solids as effective oil-adsorbent materials.

Exopolysaccharide produced by the potential probiotic Lactococcus garvieae C47: Structural characteristics, rheological properties, bioactivities and impact on fermented camel milk.

Fermented camel milk possesses a weak (liquid-like) gel structure. We aimed to 1) investigate the characteristics, bioactivities and rheological properties of the exopolysaccharide (EPS) produced by Lactococcus garvieae-C47 (exopolysaccharide-C47 product), a potential probiotic bacterium, on milk extracted from camels and 2) examine the rheological properties of the fermented camel milk produced by L. garvieae-C47. Exopolysaccharide-C47 product (molecular weight: 7.3 × 106 Da) was composed of the following monosaccharides: glucose (82.51%), arabinose (5.32%) and xylose (12.17%). The antioxidant, antitumor and α-amylase inhibitory activities of exopolysaccharide-C47 product reached up to 67.52, 59.35 and 91.0%, respectively. The apparent viscosity of exopolysaccharide-C47 product decreased with the increase in shear rate and declined by increasing the temperature up to 50 °C. The rheological properties of exopolysaccharide-C47 product are influenced by the salt type and pH value. The exopolysaccharide product produced by L. garvieae C47 possesses valuable health benefits and has the ability to improve the weak structure of fermented camel milk.

Characterization, bioactivities, and rheological properties of exopolysaccharide produced by novel probiotic Lactobacillus plantarum C70 isolated from camel milk.

Various industries highly regard the functionalities and bioactivities of bacterial polysaccharides. We aimed to characterize the exopolysaccharide (EPS) produced by novel probiotic Lactobacillus plantarum C70 (accession number KX881779) isolated from camel milk and to investigate its bioactivities and rheological properties. EPS-C70 had a weight-average molecular weight (Mw) of 3.8 × 105 Da. Arabinose (13.3%), mannose (7.1%), glucose (74.6%), and galactose (5.0%) were the major monosaccharides constituents. EPS-C70 had two endothermic peaks at 76.95 °C and 158.76 °C corresponding to glass transition (Tg) and melting point (Tm), respectively. Zeta potential and particle size of EPS-C70 were -330.71 mV and 525.5 nm, respectively. DPPH and ABTS of EPS-C70 were 75.91% and 49.42% at 10 mg/mL concentration, respectively. The cytotoxic activities against colon cancer and breast cancer lines were 88.1% and 73.1% at concentration 10 mg/mL, respectively. EPS-C70 exhibited shear-thinning behaviour. Salts and pH values had a significant impact on the rheological properties of EPS-C70.

Isolation and characterization of cellulose and α-cellulose from date palm biomass waste.

Towards the utilization of different parts of date palm biomass waste, low-concentration acid-alkali treatment was used to isolate the contained cellulose and α-cellulose. The cellulose yields achieved from the rachis, leaflet, and fiber parts of the biomass were 74.70%, 71.50%, and 73.82%, respectively, while the corresponding α-cellulose yields were 78.63%, 75.64%, and 70.40%, respectively. The cellulose samples were bleached and characterized by thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The XRD results revealed high crystallinity of both the cellulose and α-cellulose samples, while the TGA thermograms indicated that the alkali treatment completely removed lignin and hemicelluloses from the rachis. The results of this study demonstrate the promise of using date palm biomass waste as raw material to produce cellulose and α-cellulose.