Alessandro Cazonatto Galvão

Predicting the long-term stability of immobilized enzymes remains challenging due to the complex physicochemical interactions within immobilization matrices. In this study, a Physics-Informed Machine-Learning (PIML) framework was developed to investigate the deactivation behavior of β-D-galactosidase immobilized in pectin-based biohydrogels reinforced with eucalyptus sawdust (ES). The approach combines first-order deactivation kinetics with Gaussian process regression (GPR), integrating mechanistic interpretability with data-driven prediction. Structural descriptors of hydrogel rigidity, hydrogen-bond interactions, and diffusion behavior were incorporated to characterize the immobilization environment. The PIML framework provided a physically plausible representation of the experimental data while avoiding non-monotonic deactivation artifacts commonly observed in unconstrained machine learning models. Leave-one-condition-out validation yielded RMSE, MAE, and R2 values of 0.164, 0.119, and 0.625, respectively, indicating moderate predictive robustness under partially extrapolative conditions. External validation using independent, literature-derived datasets revealed reasonable transferability across thermal and storage stability regimes but substantially lower performance in operational reuse systems, suggesting the involvement of additional mechanisms, such as enzyme leakage and support degradation. The optimized formulation containing 5 wt % ES at pH 4.0 increased the estimated enzymatic half-life by 36.9%. These findings demonstrate the potential of physically constrained low-data machine learning for biocatalyst design while highlighting important transferability limitations across distinct immobilization architectures.

Salicylic acid is widely used in pharmaceutical and cosmetic applications, where reliable solubility data are critical for optimizing crystallization-based purification processes. While literature reports values for neat solvents, comprehensive measurements in binary water–alcohol mixtures over the full composition range remain scarce. In this work, the mole fraction solubility of salicylic acid was experimentally determined in the binary mixtures of water + methanol, water + ethanol, and water +2-propanol over the entire solvent composition range at temperatures from 283.2 to 323.2 K at atmospheric pressure using a gravimetric method. The experimental data were analyzed using analytical solutions of groups (ASOG), PC-SAFT, and PSRK thermodynamic models to describe the solid–liquid equilibrium behavior. PC-SAFT showed the best overall performance, yielding the lowest deviations, followed by PSRK and ASOG. The solubility increases monotonically with temperature in all systems, indicating an endothermic dissolution process. In mixed solvents, the solubility decreases sharply with an increasing water mole fraction, supporting the antisolvent effect of water. This behavior is associated with solvent polarity and specific solute–solvent interactions. Alcohols act as effective cosolvents, increasing solubility as the solvent polarity decreases. The new data sets fill important gaps in the literature and provide a consistent basis for thermodynamic modeling, supporting the improved design of crystallization and separation processes involving salicylic acid.

Intensive poultry production in humid subtropical agro-ecologies faces unique environmental challenges that compromise carcass quality, welfare, and food security. While climatic influences are recognized, the temporal dimensions of these effects remain largely underexplored. This study quantified the immediate and time-lagged (1–3 months) influences of climatic variables on 12 causes of broiler carcass condemnation in a representative subtropical hub. Longitudinal data (2021–2023) from federally inspected slaughterhouses in Santa Catarina, Brazil, a relevant case study for poultry production within Köppen Cfa and Cfb climate zones, were analyzed using Spearman rank correlation and robust regression models, including Generalized Linear Models (GLM) with a quasibinomial distribution. Total condemnation rates rose from 13.1% in 2021 to 15.5% in 2023, dominated by gastrointestinal contamination (5.0%) and skin lesions (3.5%). Regression analysis revealed that lagged precipitation was a significant predictor for arthritis and cellulitis ( p < 0.05), whereas higher temperatures and heat index reduced rejections for ascites and skin lesions ( p < 0.01). A quasibinomial GLM identified lagged heat index (β = − 0.096, p = 0.051) as a marginal predictor for inflammatory lesions. These findings suggest an association between environmental conditions during the initial stages of rearing and the final carcass quality. The established models offer insights for seasonal management across similar humid subtropical belts to mitigate economic losses and enhance production sustainability.

In many developing regions, the lack of a continuous cold chain poses a significant challenge for the preservation of table eggs. This study developed bioactive coatings based on citric pectin enriched with Cordia verbenacea DC aqueous extract to maintain egg quality under non-refrigerated conditions (25 days). A total of 144 fresh eggs were divided into a Control group and five treatment groups with increasing extract concentrations (0% to 100%). Quality was assessed through physical, chemical, and microbiological parameters, supported by principal component analysis (PCA) and random forest (RF) modeling. The results showed that all coated eggs maintained significantly higher Haugh units (classified as Grade B) compared to the control (grade C) (p < 0.05). The microbial load on the shell, a fundamental indicator of sanitary-hygienic conditions, was reduced from 70.0 ± 5.8 CFU/egg in the control to zero in the 100% extract treatment. The RF model achieved 97.06% accuracy in classifying the treatments, identifying microbial load and Haugh unit as the primary predictors of quality. This bioactive coating represents a sustainable and low-cost technology to enhance the shelf life and safety of eggs in markets without refrigeration infrastructure.