SOUTHERN JOURNAL OF SCIENCES

Background: Heat treatment is one of the most used methods to preserve food, such as orange juices, which are an excellent source of ascorbic acid. To avoid vitamin C degradation and reduce loss, fast heating is recommended. However, little is known about heat transfer during juice pasteurization. Aim: Therefore, this work aimed to determine the vitamin C content and the convective heat transfer coefficient in the pasteurization of orange juice. Methods: To perform the experiment, in the juice container, two regions were analyzed: the central region and near the wall. For the time-temperature control, thermometers were installed in the two regions mentioned. Every 120 seconds, the temperature was measured. The vitamin C content in the juice was evaluated before and after pasteurization using the iodometric method. The convective coefficient was evaluated using the method of dimensionless numbers and the experimental method. Results and Discussion: In pasteurization, the solution was heated to 80 °C, where heating lasted 3000 seconds and cooling for 2520 seconds. The graph showing the relationship of the convective heat transfer coefficient and temperature follows the same trend of the literature. The convective coefficient is higher in the region near the wall. As time passes and temperature decreases, the central region tends to equilibrium, and the coefficient becomes more constant. The vitamin C content remained constant before and after pasteurization. The values of the dimensionless numbers used in the calculations are in the same order of magnitude as the literature. Conclusions: The pasteurization did not cause ascorbic acid degradation since the heating step was fast in the heat treatment. The graphic showed that there is a dependence of the dimensionless of temperature with the dimensionless Biot and Fourier. It was noted that studying the thermal behavior in the cooling of orange juice is extremely important to ensure its quality.

Background: Background: Vitamin D plays an essential role in bone health and overall physiological function, and its deficiency is common in children and adolescents with β-thalassemia major (βTM). Iron overload, as reflected by elevated ferritin, may further influence vitamin D status. Aim: This study aimed to evaluate serum vitamin D levels in βTM patients and determine their association with ferritin levels. Methods: A total of 40 βTM patients and 20 age-matched healthy controls (aged 4–25 years) were enrolled between October 2024 and February 2025. Serum vitamin D, calcium, ferritin, and hemoglobin were measured. Statistical analysis, including correlation and logistic regression, was performed using SPSS v.26 to identify predictors of vitamin D deficiency. Results: Vitamin D deficiency was highly prevalent among βTM patients (70%) compared with controls. Patients showed significantly lower vitamin D levels (17.32±1.56) than controls (25.34±1.76). Vitamin D levels were positively correlated with age (r = 0.788), calcium (r = 0.772), and hemoglobin (r = 0.771), and negatively correlated with ferritin (r = −0.517). Logistic regression demonstrated that ferritin >1000 ng/mL strongly predicted vitamin D deficiency (OR = 17.875; 95% CI: 3.258–98.074; p = 0.001), while younger age ( < 10 years) also increased the odds of deficiency (OR = 5.200; p = 0.018). Discussion: D deficiency is a prevalent and intrinsic metabolic disturbance in β-thalassemia major, closely linked to chronic iron overload and elevated ferritin levels. This interplay disrupts hepatic vitamin D hydroxylation, induces inflammation, and contributes to endocrine and skeletal complications, highlighting ferritin as a key predictor of deficiency in these patients. Conclusion: Vitamin D deficiency is highly prevalent in βTM and is strongly associated with elevated ferritin levels, suggesting that iron overload is a significant predictor. Integrating vitamin D assessment into routine monitoring may support better management of disease-related metabolic disturbances in patients with βTM.

It is investigated the effect of synthesized organic compounds of 6-hydroxy-2,2,4-trimethyl-1,2- dihydroquinoline, its derivatives, and hydrogenated analogs. These compounds affected the height of seedlings when they were used for pre-sowing seed treatment of the following ornamental plants: annual ornamental grass – scarlet sage (Salvia splendens) and woody plant – yellow rhododendron (Rhododendron luteum). Prior to the sprouting process, the seeds of Rh. luteum and S. splendens were soaked in water solutions of compounds with concentrations of 0.01%, 0.05%, and 0.1% for 18 hours. Dihydro- and tetrahydroquinolines with a concentration of 0.05% proved to be the most effective for both plants. For Rhododendron luteum, the compounds of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline, its derivatives, and hydrogenated analogs with a concentration of 0.1% proved to be the most effective. Dihydroquinolines at concentrations of 0.05 and 0.1% proved to have the strongest effect when applied to the studied perennial woody plant (Rhododendron luteum). Dihydroquinoline at the concentration of 0.05% also proved to be effective when applied to the annual grass (Salvia splendens). For annual S. splendens, tetrahydroquinoline at concentrations of 0.01 and 0.05% appeared to be the most effective. The pre-sowing seed treatment of grass Salvia splendens and woody plant Rhododendron luteum with the studied compounds demonstrated that their effect on the height of the seedlings is species-specific. The pre-sowing seed treatment of Rh. luteum and S. splendens allows increasing the height of the seedlings by 3-61 % and 17-25 %, respectively. It is suggested using the compounds of 6-hydroxy-2,2,4- trimethyl-1,2-dihydroquinoline, its derivatives, and hydrogenated analogs as effective growth stimulators for ornamental grasses and woody plants.