Filters
Empirical Modeling of the Drying Kinetics of Red Beetroot (Beta vulgaris L.; Chenopodiaceae) with Peel, and Flour Stability in Laminated and Plastic Flexible Packaging
Despite the high global production of beetroot (Beta vulgaris L.), its peel is often discarded. Transforming beetroot into flour can reduce waste, improve food security, and decrease environmental pollution. However, large-scale feasibility depends on understanding drying kinetics and optimal storage conditions. This study aimed to investigate the effects of different temperatures in the convective drying of whole beetroot and evaluate the influence of laminated flexible and plastic packaging on flour stability over two months. Drying kinetics were analyzed using five models, with the Page and Logarithm models showing the best fit (R2 > 0.99). Def values (1.27 × 10−9 to 2.04 × 10−9 m2 s−1) increased with rising temperatures while drying time was reduced (from 820 to 400 min), indicating efficient diffusion. The activation energy was 29.34 KJ mol−1, comparable to other plant matrices. Drying reduced moisture and increased ash concentration in the flour. The flour showed a good water adsorption capacity and low cohesiveness, making it marketable. Laminated packaging was more effective in controlling physicochemical parameters, reducing hygroscopicity, and maintaining quality over 60 days. In summary, the Page model can predict beetroot drying kinetics effectively, and laminated packaging can control flour stability.
Impact of Dried Garlic on the Kinetics of Bacterial Growth in Connection with Thiosulfinate and Total Phenolic Content
The health properties of garlic (Allium sativum L.) are attributed to thiosulfinates, flavonoids, phenols, and bioactive polysaccharides. These compounds, however, can degrade during processing methods. As hot air-drying is a commonly used preservation method due to its relatively simple operation, this study investigated the effects of garlic slices dried at various temperatures (50, 70, and 90 °C) on the growth kinetic parameters of model strain Escherichia coli ATCC 25922, the total thiosulfinate content (TTC), and the total phenolic content (TPC). Observations showed that the concentration of garlic extracts was a significant factor influencing the kinetics of bacterial growth, while the garlic drying temperature appeared to have no effect on E. coli activity. Analysis of TTS in fresh and dried garlic did not reveal statistically significant differences in their levels. However, hot air drying at 50 °C significantly reduced the TPC by nearly 25%, whereas drying garlic at higher temperatures (70 °C and 90 °C) did not lead to a significant loss in TPC compared to the raw samples. The determined growth kinetic parameters of the tested E. coli strain could serve as a basis for selecting optimal drying process conditions and extract concentrations when designing garlic products with enhanced antimicrobial properties.