AppliedChem, Volume 5, Issue 2 (June 2025) – 6 articles

The effects of different carrier agents—pea protein (PP), rice protein (RP), bean protein (BP), whey protein (WP), and maltodextrin (MT, as a control)—on pitaya juice encapsulation via spray drying were evaluated. Juice and carrier mixtures (30% w/v) were dried at 150 °C, and the resulting powders were analyzed for water activity (aw), hygroscopicity (Hg), water solubility (WSI), bulk density (BD), glass transition temperature (Tg), water absorption (WAI), antioxidant activity (AA), total polyphenol content (TPC), total betalain (TB) content, and TB stability. Vegetable proteins showed promising results, significantly impacting the protein content, Hg content, WAI, WSI, AA, TPC, and TB content and resulting in high Tg values. PP showed the best results, with high betalain retention (>30%), high TPC and AA, high protein levels, and low Hg, similarly to MT. WP had the highest TB, AA, and TPC but the lowest Tg (47.21 °C), thus reducing stability. Encapsulates obtained with plant protein-based wall materials presented high Tg (>58 °C); low aw, WSI, and Hg; high protein contents >40%; and adequate retention of bioactive compounds, with low degradation rate constants and long half-lives. Overall, plant proteins are promising alternatives to traditional carriers, offering improved stability and functionality in encapsulated products. Full article

The aim of this study was to quantify the total extraction yield (GEY) of polyphenols from pomegranate peels using a solid–liquid extraction process without evaporation but with UV-Vis spectrophotometry. Extraction kinetics models were tested to evaluate the extract yield (GEY), total phenolic compounds (TPCs), total flavonoids (TFCs), and condensed tannins (CTCs). The results showed maximum values of 45% for GEY, 97.560 mg EAG/g db for TPC, 4.416 mg EQ/g db for TFC, and 0.412 mg EC/g db for CTC, obtained with a methanol/water mixture (75/25, v/v) for 24 h. Spectrophotometry proved to be a reliable method for quantifying the total extraction yield, with a correlation of 99.79% compared to the conventional method. The second-order kinetic model accurately described the mass transfer mechanisms of the bioactive compounds studied. This study provides important insights into the mass transfer mechanisms during the extraction of bioactive compounds, facilitating the design, optimization, and control of large-scale processes for the recovery of pomegranate waste. Full article

The photochemical production of tropospheric ozone (O₃) is very closely linked to seasonal cycles and peaks in solar radiation occurring during warm seasons. In the Mediterranean Basin, which is a hotspot for climate and air mass transport mechanisms, boreal warm seasons cause a notable increase in tropospheric O₃, which unlike stratospheric O₃ is not beneficial for the environment. At the Lamezia Terme (code: LMT) World Meteorological Organization—Global Atmosphere Watch (WMO/GAW) station located in Calabria, Southern Italy, peaks of tropospheric O₃ were observed during boreal summer and spring seasons, and were consequently linked to specific wind patterns compatible with increased photochemical activity in the Tyrrhenian Sea. The finding resulted in the introduction of a correction factor for O₃ in the O₃/NO_x (ozone to nitrogen oxides) ratio “Proximity” methodology for the assessment of air mass aging. However, some of the mechanisms driving O₃ patterns and their correlation with other parameters at the LMT site remain unknown, despite the environmental and health hazards posed by tropospheric O₃ in the area. In general, the issue of ozone photochemical pollution in the region of Calabria, Italy, is understudied. In this study, the behavior of O₃ at the site is assessed with remarkable detail using nine years (2015–2023) of data and correlations with surface temperature and solar radiation. The evaluations demonstrate non-negligible correlations between environmental factors, such as temperature and solar radiation, and O₃ concentrations, driven by peculiar patterns in local wind circulation. The northeastern sector of LMT, partly neglected in previous works, yielded higher statistical correlations with O₃ than expected. The findings of this study also indicate, for central Calabria, the possibility of heterogeneities in O₃ exposure due to local geomorphology and wind patterns. A case study of very high O₃ concentrations reported during the 2015 summer season is also reported by analyzing the tendencies observed during the period with additional methodologies and highlighting drivers of photochemical pollution on larger scales, also demonstrating that near-surface concentrations result from specific combinations of multiple factors. Full article

In this study, copper ferrite nanoparticles, a type of ferrimagnetic spinel ferrite, were synthesized using the sol-gel auto-combustion method with three different fuels: citric acid, urea, and ethylene glycol. The crystal structures of the synthesized samples were analyzed using X-ray diffraction (XRD), and the growth of secondary phases like Fe₂O₃ and CuO for samples prepared with urea and ethylene glycol indicated the presence of impurities. Additionally, we observed that the particle size varied significantly with the type of fuel, being the smallest for citric acid and the largest for urea. The electrical and magnetic properties showed strong correlations with the particle size and the presence of impurities. In particular, the optical band gap values, derived from UV-Vis spectroscopy, varied significantly with the choice of fuel, ranging from 2.06 to 3.75 eV. The highest band gap of 3.75 eV was observed in samples synthesized with citric acid. Magnetic properties were measured using a vibrating sample magnetometer (VSM), and it was found that the copper ferrite synthesized with citric acid exhibited the highest values of magnetic saturation and coercivity. These findings demonstrate that the choice of fuel during the synthesis process has substantial impacts on the structural, optical, and magnetic properties of CuFe₂O₄ nanoparticles. Full article

This study investigated the effectiveness of a ligand known as (2-Mercapyo-phenylimino)-1,3-dihydro-indol-2-one-based ligand, in removing stable/radioactive cesium and cobalt from contaminated wastewater. Several parameters, such as contact duration, temperature, adsorbent quantity, pH of the medium, and concentration of adsorbate, have been investigated as primary active parameters impacting the adsorption process. Regarding the stable isotopes, the concentrations of Co²⁺ and Cs⁺ were measured before and after the treatment processes using the Optical Emissions Spectroscopy with Inductively Coupled Plasma (ICP-OES) technique. Additionally, kinetic and equilibrium isotherm models were applied to understand the equilibrium data. Both Cs⁺ and Co²⁺ were ideally eliminated after 120 and 60 min, respectively. The optimal pH for Cs⁺ was 6.3, while that for Co²⁺ was 5. The results indicate that the adsorption process is endothermic for Co²⁺ and exothermic for Cs⁺. Three thermodynamic parameters (∆G°, ∆H°, and ∆S°) were calculated. The reported R² values for the Freundlich and Langmuir models showed that the adsorption process for Cs⁺ and Co²⁺ always followed these isotherms, regardless of the temperature used. For Cs⁺, the maximum single-layer capacity (q_max) was 15.10 mg g⁻¹, while for Co²⁺, it was 62.11 mg g⁻¹. When the aqueous medium was spiked with both radioisotopes individually, the elimination of ⁶⁰Co and ¹³⁴Cs achieved maximum values of 99 and 86%, respectively, within 120 min. It can be concluded that the ligand effectively removed cobalt and cesium from wastewater, with higher adsorption for cobalt. Full article

Capsaicinoids obtained from lyophilized serrano chili by sorbitan monooleate solutions were investigated. Sorbitan monooleate was as effective as methanol in extracting capsaicin and dihydrocapsaicin (DHC). Subsequently, a Box–Behnken design was used to optimize capsaicin, DHC, and polyphenol extraction, as well as to evaluate the antioxidant capacity of dehydrated serrano chili. Particle size (PS) (20–60 mesh), processing temperature (55–75 °C), and sorbitan concentration (1.5–2.5%) were selected as independent variables. The statistical analysis showed that the quadratic models adequately describe the response of the concentration of capsaicin and DHC, but not with polyphenols and antioxidant capacity. The highest extraction of capsaicin (~620 mg/100 g dw) and DHC (~520 mg/100 g dw) was achieved with the combination of sorbitan at 2%, temperature at 65 °C, and PS from 40 mesh. Experimental and predicted values were closely consistent. Meanwhile, extracts with the highest antioxidant potential (~7510 and ~5820 µM of Trolox Eq/100 g dw for ABTS and FRAP, respectively) were those extracted in sorbitan and PS from 40 mesh. In contrast, the highest values of polyphenols (~171 mg gallic acid Eq/100 g dw) were found in the extracts prepared at 75 °C. These results suggest that sorbitan monooleate solutions can be an effective, non-toxic, and environmentally responsible way to obtain capsaicinoids and bioactive compounds from dehydrated serrano chili. Full article